JP6456170B2 - Connection method and joined body - Google Patents

Description

  The present invention relates to a connection method and a joined body.

  Conventionally, an ultraviolet curable adhesive is used as an adhesive for connecting a substrate and an electronic component such as an IC chip or a flexible flat cable. The ultraviolet curable adhesive is applied between the substrate and the electronic component, and is cured by being irradiated with ultraviolet rays. By doing so, the substrate and the electronic component are connected.

In the connection, when the ultraviolet curable adhesive is used, unlike the case of using the thermosetting adhesive, there is no step of heating and pressing the substrate and the electronic component. Therefore, there is no warping of the substrate due to heating, and connection using an ultraviolet curable adhesive is suitable for connection to a thin substrate in recent years.
Further, when an ultraviolet curable adhesive is used, the substrate and the electronic component are not damaged by heat.

  On the other hand, a joined body connected using an ultraviolet curable adhesive may have poor connection reliability. In addition, when exposed to a high temperature and high humidity environment for a long period of time, there is a problem that the connection resistance between the substrate and the electronic component is increased.

Therefore, for the purpose of improving connection reliability, in the terminal electrode that is formed on the translucent insulating substrate and is pressure-bonded and fixed to the bump electrode of the connection plate or semiconductor chip of the connection film via the ultraviolet curable resin, A terminal electrode made of a metal having an opening has been proposed (see, for example, Patent Document 1).
However, this proposed technique is not sufficient as a countermeasure for the problem that the connection resistance between the substrate and the electronic component increases when exposed to a high temperature and high humidity environment for a long period of time.

Japanese Examined Patent Publication No. 6-42124

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, an object of the present invention is to provide a connection method and a bonded body that are excellent in connection reliability even when exposed to a high temperature and high humidity environment for a long period of time.

Means for solving the problems are as follows. That is,
<1> A connection method for anisotropically connecting the wiring of the first circuit member and the terminal of the second circuit member,
Light is transmitted from the first circuit member side to the photocurable anisotropic conductive film disposed between the first circuit member and the second circuit member through the first circuit member. Including a light irradiation step of irradiating
In the first circuit member, the wiring is disposed on a light transmissive substrate,
The wiring has an opening;
The area ratio of the opening in the wiring is 5% to 70%,
In the connection method, a width of the wiring in the first circuit member is 400 μm or more.
<2> The connection method according to <1>, wherein an area ratio of the opening in the wiring is 10% to 50%.
<3> The photocurable anisotropic conductive film contains conductive particles,
<1> to <2> in which the width [A (μm)] of the opening and the average particle diameter [B (μm)] of the conductive particles satisfy (A) / (B) ≦ 4.0. The connection method according to any one of the above.
<4> A joined body produced by the connection method according to any one of <1> to <3>.

  According to the present invention, it is possible to solve the conventional problems and achieve the object, and a connection method and a joined body that are excellent in connection reliability even when exposed to a high temperature and high humidity environment for a long period of time. Can be provided.

FIG. 1 is a schematic top view of an example of a first circuit member. FIG. 2 is a schematic top view of another example of the first circuit member. FIG. 3 is a schematic top view of an example of wiring.

(Connection method and joined body)
The connection method of the present invention includes at least a light irradiation step, and further includes other steps as necessary.
The connection method is a connection method in which the wiring of the first circuit member and the terminal of the second circuit member are anisotropically conductively connected.

  The joined body of the present invention is manufactured by the connection method.

<Light irradiation process>
As the light irradiation step, a first photoconductive anisotropic conductive film disposed between the first circuit member and the second circuit member is formed on the first circuit member side from the first circuit member side. If it is the process of irradiating light through this circuit member, there will be no restriction | limiting in particular, According to the objective, it can select suitably.

<< first circuit member >>
The first circuit member is not particularly limited as long as it has wiring on a light-transmitting substrate, and can be appropriately selected according to the purpose. For example, the first circuit member can be selected from a wiring board, an electronic component, a flexible wiring board (FPC). ) And the like. There is no restriction | limiting in particular as said wiring board, According to the objective, it can select suitably, For example, an LCD board | substrate, a PDP board | substrate, an organic electroluminescent board | substrate etc. are mentioned.

-Light transmissive substrate-
Examples of the light transmissive substrate include a glass substrate and a plastic substrate. The light transmittance in the light transmissive substrate is not particularly limited as long as it can transmit the light irradiated to the photocurable anisotropic conductive film, and can be appropriately selected according to the purpose. Note that the light transmittance of the light-transmitting substrate with respect to the irradiated light does not need to be 100%.

  There is no restriction | limiting in particular as the transmittance | permeability of the light of wavelength 200nm-750nm in the said light-transmitting base material, Although it can select suitably according to the objective, 50%-100% are preferable, and 70%-100% More preferred.

−Wiring−
In the first circuit member, the wiring is disposed on the light transmissive substrate.
The wiring has an opening.
The area ratio of the opening in the wiring is 5% to 70%.
The width of the wiring in the first circuit member is 400 μm or more.

  In order to photocure the photocurable anisotropic conductive film in the anisotropic conductive connection, it is necessary to irradiate the photocurable anisotropic conductive film with light. Done. In that case, a light-transmitting substrate is usually used as the substrate of the circuit member, but the wiring arranged on the light-transmitting substrate is usually a metal or the like and does not transmit light. . Therefore, due to the presence of the wiring, photocuring may not be sufficiently performed in a part of the photocurable anisotropic conductive film.

  The inventors examined the relationship between the arrangement of the wiring and the photocuring of the photocurable anisotropic conductive film. As a result, when the width of the wiring is narrow (less than 400 μm), even if light is shielded by the wiring, the light irradiated to the photocurable anisotropic conductive film from between the wiring is diffracted. The present inventors have also found that sufficient photocuring for anisotropic conductive connection can be performed in the back side portion of the wiring in the photocurable anisotropic conductive film. In other words, if the width of the wiring is wide (400 μm or more) even if the light irradiated to the photocurable anisotropic conductive film from between the wirings is diffracted, the photocurable anisotropic conductive film It has been found that photocuring sufficient for anisotropic conductive connection cannot be performed in the back side of the wiring.

  The inventors further studied. As a result, it has been found that even when the width of the wiring is wide (400 μm or more), the photocurable anisotropic conductive film can be irradiated with light through the wiring by providing an opening in the wiring. However, if the opening is provided too much in the wiring, the conductivity of the wiring is lowered. On the other hand, when there are few openings in the said wiring, the photocuring of the part of the back side of the said wiring in the said photocurable anisotropic conductive film will become inadequate. Therefore, the present inventors have found that there is a suitable range for the ratio of the area of the opening in the wiring, which is 5% to 70%.

The width of the wiring is not particularly limited as long as it is 400 μm or more, and can be appropriately selected according to the purpose. There is no restriction | limiting in particular as an upper limit of the width of the said wiring, According to the objective, it can select suitably, For example, 1,000 micrometers, 2,000 micrometers, etc. are mentioned.
Here, the width of the wiring is an average value, but it does not mean the average value of the widths of all the wirings arranged on the first circuit member, but an anisotropic conductive connection. It is an average value of the width in the wiring part which contacts the said photocurable anisotropic conductive film.

The area ratio of the opening in the wiring is 5% to 70%, preferably 10% to 50%. When the area ratio is within a preferable range, the connection resistance after the environmental test is more excellent.
The area ratio of the opening can be obtained by the following formula.
Opening area ratio (%) = (total opening area) / (total wiring area)
Here, the total area of the opening is the total area of the opening in the wiring portion that contacts the photocurable anisotropic conductive film when anisotropic conductive connection is made. The total area of the wiring is the total area of the wiring in the wiring portion in contact with the photocurable anisotropic conductive film when anisotropic conductive connection is made.

There is no restriction | limiting in particular as an opening shape in the said wiring, According to the objective, it can select suitably, For example, circular, a rectangle, etc. are mentioned.
There is no restriction | limiting in particular as a formation method of the said opening, According to the objective, it can select suitably, For example, photolithography etc. are mentioned.

There is no restriction | limiting in particular as the width | variety of the said opening, Although it can select suitably according to the objective, 1 micrometer-20 micrometers are preferable, 2 micrometers-15 micrometers are more preferable, and 3 micrometers-9 micrometers are especially preferable.
The width of the opening is not particularly limited and may be appropriately selected depending on the purpose. However, the width of the opening [A (μm)] and the conductive property are related to the size of the conductive particles described later. The average particle diameter [B (μm)] of the conductive particles preferably satisfies (A) / (B) ≦ 4.0. If (A) / (B)> 4.0, the conductive particles crushed during anisotropic conductive connection are trapped in the opening and do not come into contact with the conductive portion of the wiring, resulting in connection resistance. May decrease.
Here, the width of the opening means a diameter of an inscribed circle of the opening. That is, when the shape of the opening is circular, the diameter of the circle is the width. When the shape of the opening is a square, the length of one side of the square is the width. When the shape of the opening is a rectangle, the length of the short side of the rectangle is the width.
The width of the opening is an average value of 50 openings.

There is no restriction | limiting in particular as a material of the said wiring, According to the objective, it can select suitably, For example, a metal, a metal oxide, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
The conductive portion in the wiring is preferably non-light transmissive. The conductive portion is a portion excluding the opening in the wiring. When the conductive portion is light transmissive, the significance of providing the opening in the wiring is lowered.

  There is no restriction | limiting in particular as a magnitude | size and a shape of a said 1st circuit member, According to the objective, it can select suitably.

Here, an example of the first circuit member will be described with reference to the drawings.
FIG. 1 is a schematic top view of an example of a first circuit member.
The first circuit member 1 includes a light transmissive substrate 12 and a wiring 11 disposed on the light transmissive substrate 12. In the wiring 11, square openings 11A are formed at equal intervals in a rectangular conductive portion 12B.

FIG. 2 is a schematic top view of another example of the first circuit member.
The first circuit member 1 includes a light transmissive substrate 12 and a wiring 11 disposed on the light transmissive substrate 12. In the wiring 11, circular openings 11A are formed at equal intervals in a rectangular conductive portion 12B.

Subsequently, an example of the opening in the wiring will be described with reference to the drawings.
FIG. 3 is a schematic top view of an example of wiring.
In the wiring 11, square openings 11A are formed at equal intervals in the conductive portion 12B. One side of the opening is 3 μm, and the interval between adjacent openings is also 3 μm. Therefore, the area ratio of the opening in the wiring is 25% as can be seen from FIG.

<< second circuit member >>
As long as it has a terminal, there is no restriction | limiting in particular as said 2nd circuit member, According to the objective, it can select suitably, For example, a wiring board, an electronic component, a flexible wiring board (FPC) etc. are mentioned.

  There is no restriction | limiting in particular as said wiring board, According to the objective, it can select suitably, For example, an LCD board | substrate, a PDP board | substrate, an organic electroluminescent board | substrate etc. are mentioned.

  Examples of the electronic component include an IC chip and a TAB tape on which the IC chip is mounted.

  There is no restriction | limiting in particular as a magnitude | size and a shape of a said 2nd circuit member, According to the objective, it can select suitably.

<< Photocurable Anisotropic Conductive Film >>
The photocurable anisotropic conductive film preferably contains conductive particles, and further contains other components such as a photocurable resin and a photocuring agent as necessary.
The photocurable anisotropic conductive film is disposed between the first circuit member and the second circuit member.
Examples of a method for disposing the photocurable anisotropic conductive film between the first circuit member and the second circuit member include, for example, the photocurable resin on the first circuit member. The method of performing the 1st arrangement | positioning process which arrange | positions an anisotropic conductive film, and the 2nd arrangement | positioning process which arrange | positions the said 2nd circuit member on the said photocurable anisotropic conductive film is mentioned.

-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 during 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 photocurable anisotropic conductive film, Although it can select suitably according to the objective, With respect to the said photocurable anisotropic conductive film, 1 mass%-15 mass% are preferable, and 3 mass%-10 mass% are more preferable.

-Photocurable resin-
There is no restriction | limiting in particular as said photocurable resin, According to the objective, it can select suitably, For example, photoradical curable resin, photocationic curable resin, etc. are mentioned.

There is no restriction | limiting in particular as said radical photocurable resin, According to the objective, it can select suitably, For example, epoxy (meth) acrylates, urethane (meth) acrylates, (meth) acrylate oligomer etc. are mentioned. .
Other examples of the photo radical curable resin include methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylol propane triacrylate, dimethylol tricyclodecane diacrylate, tetra Methylene glycol tetraacrylate, 2-hydroxy-1,3-diacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxyethoxy) phenyl] Examples include propane, dicyclopentenyl acrylate, tricyclodecanyl acrylate, and tris (acryloxyethyl) isocyanurate. Moreover, what made these acrylates into methacrylate can also be used.
These may be used individually by 1 type and may use 2 or more types together.

The photocationic curable resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, oxetane resin, alicyclic type Examples thereof include epoxy resins and modified epoxy resins thereof.
These may be used individually by 1 type and may use 2 or more types together.

  Further, the photo radical curable resin and the photo cation curable resin may be mixed and used together.

  There is no restriction | limiting in particular as content of the said photocurable resin in the said photocurable anisotropic conductive film, Although it can select suitably according to the objective, With respect to the said photocurable anisotropic conductive film 20 mass%-60 mass% are preferable, and 30 mass%-50 mass% are more preferable.

-Light curing agent-
There is no restriction | limiting in particular as said photocuring agent, According to the objective, it can select suitably, For example, the hardening | curing agent etc. which generate | occur | produce active cation seed | species or radical seed | species by the light of wavelength range 200nm -750nm are mentioned.

  There is no restriction | limiting in particular as a radical photocuring agent which generate | occur | produces radical seed | species, According to the objective, it can select suitably, For example, an alkyl phenone type photoinitiator, an acyl phosphine oxide type photoinitiator, a titanocene type | system | group Examples thereof include polymerization initiators and oxime ester photopolymerization initiators. These can harden various said photo-radical curable resins satisfactorily.

  There is no restriction | limiting in particular as a photocationic hardening | curing agent which generate | occur | produces a cationic seed | species, According to the objective, it can select suitably, For example, a sulfonium salt, onium salt, etc. are mentioned. These can well cure various photocationic curable resins.

  In addition, as a hardening | curing agent which generate | occur | produces an active cation seed | species or radical seed | species by the light of the said wavelength region 200nm-750nm, a photoradical hardening | curing agent (Brand name: Irgacure 651, Ciba Specialty Chemicals company make), a photocation, for example. Examples thereof include a curing agent (trade name: Irgacure 369, manufactured by Ciba Specialty Chemicals).

  Further, the photo radical curing agent and the photo cation curing agent may be mixed and used together.

  The content of the photocuring agent in the photocurable anisotropic conductive film is not particularly limited and can be appropriately selected according to the purpose.For the photocurable anisotropic conductive film, 0.5 mass%-10 mass% are preferable, and 1 mass%-5 mass% are more preferable.

-Other ingredients-
Examples of the other components include a film forming resin, rubber, and a silane coupling agent.

--- 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.

  The content of the film-forming resin in the photocurable anisotropic conductive film is not particularly limited and can be appropriately selected according to the purpose.For the photocurable anisotropic conductive film, 20 mass%-60 mass% are preferable, and 30 mass%-50 mass% are more preferable.

--Rubber--
There is no restriction | limiting in particular as said rubber | gum, According to the objective, it can select suitably, For example, urethane rubber, acrylic rubber, silicone rubber etc. are mentioned.

  There is no restriction | limiting in particular as content of the said rubber in the said photocurable anisotropic conductive film, Although it can select suitably according to the objective, 1 mass with respect to the said photocurable anisotropic conductive film % To 10% by mass is preferable, and 2% to 8% by mass is more preferable.

--Silane coupling agent--
The silane coupling agent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include an epoxy silane coupling agent, an acrylic silane coupling agent, a thiol silane coupling agent, and an amine silane. A coupling agent etc. are mentioned.
There is no restriction | limiting in particular as content of the said silane coupling agent in the said photocurable anisotropic conductive film, According to the objective, it can select suitably.

  There is no restriction | limiting in particular as average thickness of the said photocurable anisotropic conductive film, Although it can select suitably according to the objective, 2 micrometers-60 micrometers are preferable, 5 micrometers-30 micrometers are more preferable, 10 micrometers-20 micrometers are especially. preferable.

  In the light irradiation step, the light curable anisotropic conductive film is irradiated with light from the first circuit member side through the first circuit member.

The light is not particularly limited as long as it is a light capable of curing the photocurable resin, and can be appropriately selected according to the purpose. However, light having a wavelength of 200 nm to 750 nm is preferable, and a wavelength of 200 nm to 400 nm is preferable. Light is more preferred.
Moreover, there is no restriction | limiting in particular as a light source which emits the said light, According to the objective, it can select suitably, For example, an LED light source, a UV lamp light source, etc. are mentioned.

  There is no restriction | limiting in particular as irradiation time of the said light, Although it can select suitably according to the objective, 0.3 second-5.0 second is preferable and 0.5 second-2.0 second is more preferable.

  When irradiating the light, it is preferable to further press the second circuit member. There is no restriction | limiting in particular as pressure of a press, Although it can select suitably according to the objective, 1 MPa-5 MPa are preferable.

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

Example 1
<Production of photocurable anisotropic conductive film>
The following formulations were mixed uniformly to prepare a mixture.
-Formulation-
Phenoxy resin (Product name: YP50, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) 40 parts by mass Acrylate (Product name: M-315, manufactured by Toagosei Co., Ltd.) 15 parts by mass Urethane acrylate (Product name: M-1600, manufactured by Toagosei Co., Ltd.) 25 Part by mass Rubber component (Product name: SG80H, manufactured by Nagase ChemteX Corporation) 5 parts by mass Phosphoric acid acrylate (Product name: P-1M, manufactured by Kyoeisha Chemical Co., Ltd.) 1 part by mass Photoradical curing agent (Product name: Irgacure OXE02, BASF Corporation) 3 parts by mass Ni / Au plated acrylic resin particles (average particle diameter 5 μm) 5 parts by mass A bar coater so that the average thickness after drying on the silicone-treated PET (polyethylene terephthalate) is 10 μm. It apply | coated and dried for 5 minutes at 70 degreeC, and produced the photocurable anisotropic conductive film.

<Manufacture of joined body>
The joined body was manufactured by the following method.

-First circuit member-
As the first circuit member, a PET film having ITO / metal wiring (Dexerials Corporation evaluation base material, PET film thickness 0.5 mm) was used.
The first circuit member has an ITO / metal wiring having a width of 590 μm, and the pitch between the ITO / metal wiring is 600 μm and L / S = 59/1.
In addition, a square opening with a side of 3 μm is formed in a mesh shape on the ITO / metal wiring by photolithography. The distance between the openings is 3 μm. The area ratio of the opening in the ITO / metal wiring is 25%.

-Second circuit member-
As a second circuit member, a flexible substrate (chip on flex: COF) (base material for evaluation by Dexerials Corporation, 600 μm P (pitch), Cu 12 μmt (thickness) -Au plating, L / S = 59/1, PI (polyimide) 25 μmt (thickness) —S′perflex substrate) was used.

The photocurable anisotropic conductive film slit to a width of 1.5 mm was disposed on the first circuit member. When arranging, it was pasted at 80 ° C., 1 MPa, and 1 second. Subsequently, the second circuit member was arranged on the photocurable anisotropic conductive film so as not to protrude from the photocurable anisotropic conductive film. Subsequently, while applying a pressure of 3 MPa with a pressing tool (width 1.5 mm) through a buffer material (Teflon (registered trademark), thickness 0.2 mm), the first circuit member side from the first circuit member side The photocurable anisotropic conductive film was irradiated with 180 mW / cm ² (wavelength 365 nm) for 1 second through the circuit member. Thus, a joined body was obtained.

<Evaluation>
The following evaluation was performed about the produced joined_body | zygote. The results are shown in Table 1-1.

<< Connection reliability >>
Using a digital multimeter (trade name: Digital Multimeter 7561, manufactured by Yokogawa Electric Corporation), connection resistance after initial connection resistance (Ω) and environmental test (60 ° C./95% RH / 100 hr) ( Ω) was measured. Evaluation was made according to the following evaluation criteria. The results are shown in Table 1-1.
〔Evaluation criteria〕
○: Connection resistance value is 1Ω or less △: Connection resistance value is more than 1Ω and 10Ω or less ×: Connection resistance value is more than 10Ω

(Examples 2 to 11 and Comparative Examples 1 to 4)
In Example 1, a joined body was obtained in the same manner as in Example 1 except that the interval between the openings, the length of one side of the opening, and the opening area ratio were as shown in Table 1-1 and Table 1-2. Was made.
About the obtained joined body, evaluation similar to Example 1 was performed. The results are shown in Table 1-1 and Table 1-2.

When the area ratio of the opening of the wiring was less than 5%, the light did not sufficiently reach the photocurable anisotropic conductive film on the back side of the wiring, and the connection resistance before and after the environmental test was insufficient.
On the other hand, when the area ratio of the opening of the wiring exceeds 70%, the conductive portion in the wiring is reduced, so that the connection resistance after the environmental test is insufficient.

  When the area ratio of the opening in the wiring was 10% to 50%, the connection resistance after the environmental test was very excellent.

(Examples A-1 to A-4 and Comparative Examples A-1 to A-4)
Subsequently, the wiring width (Line Width) and the wiring interval (Space Width) in the first circuit member were varied, and the connection resistance value and the reaction rate were evaluated. The manufacturing conditions of the joined body were the same as in Example 1.
The results are shown in Tables 2-1 to 2-4.

The connection resistance value was measured by the same method as in Example 1.
The reaction rate was measured using an HPLC analyzer after peeling the flexible substrate from the bonded body, sampling from the ACF pressure-bonded portion. A sample of 0.05 mg was dissolved in acetonitrile and injected into a separation column (10 cm, 40 ° C.) to obtain a chromatogram. The analysis conditions were as follows.
Acetonitrile room temperature extraction-HPLC / DAD method Extraction: Acetonitrile 40 μL
Equipment: UPLC (manufactured by Waters), Method: Hannorutu
Gradient conditions: A60%, B40% (hold for 1 minute) → A1%, B99% (hold for 6 minutes) after 5 minutes, A is water, B is acetonitrile Analysis wavelength: 210-400 nm

The photocurable anisotropic conductive film used in Comparative Examples A-1 to A-4 and Examples A-1 to A-4 is the same as the photocurable anisotropic conductive film used in Example 1. is there.
In Comparative Examples A-1 to A-4, no opening is provided in the wiring of the first circuit member. That is, the distance between the openings, the length of one side of the opening, and the opening area ratio are the same as in Comparative Example 1.
In Examples A-1 to A-4, the wiring conditions of the first circuit member are the same as the wiring conditions of the first circuit member of Example 1. That is, the opening interval is 3 μm, the length of one side of the opening is 3 μm, and the opening area ratio is 25%.

From Comparative Examples A-1 to A-4, if the width of the wiring is not 400 μm or more, good connection resistance is excellent even if no opening is provided in the wiring. This is presumably because when the width of the wiring is narrow, light reaches the photocurable anisotropic conductive film on the back side of the wiring due to light diffraction.
From Examples A-2 to A-4, even when the width of the wiring is wide, if the opening is provided in the wiring, the connection resistance is better than that in the case where the opening is not provided in the wiring.

  In the connection method of the present invention, even when a non-light-transmitting wiring material is used for the wiring of the circuit member, a bonded body that sufficiently cures the photocurable anisotropic conductive film and has excellent connection resistance after an environmental test is obtained. Since it is obtained, it can be suitably used for anisotropic conductive connection by photocuring.

DESCRIPTION OF SYMBOLS 1 1st circuit member 11 Wiring 11A Opening 11B Conductive part 12 Light transmissive base material

Claims (4)

A connection method for anisotropically conductively connecting the wiring of the first circuit member and the terminal of the second circuit member,
Light is transmitted from the first circuit member side to the photocurable anisotropic conductive film disposed between the first circuit member and the second circuit member through the first circuit member. Including a light irradiation step of irradiating
In the first circuit member, the wiring is disposed on a light transmissive substrate,
The wiring has an opening;
The area ratio of the opening in the wiring is 5% to 70%,
Connection lateral direction of the width of the wiring in the first circuit member, characterized in that at 400μm or more.   The connection method according to claim 1, wherein an area ratio of the opening in the wiring is 10% to 50%. The photocurable anisotropic conductive film contains conductive particles,
The width [A (μm)] of the opening and the average particle diameter [B (μm)] of the conductive particles satisfy (A) / (B) ≦ 4.0. The connection method described in 1. A joined body in which the wiring of the first circuit member and the terminal of the second circuit member are anisotropically conductively connected through a cured product of a photocurable anisotropic conductive film,
In the first circuit member, the wiring is disposed on a light transmissive substrate,
The wiring has an opening;
The area ratio of the opening in the wiring is 5% to 70%,
The joined body, wherein a width of the wiring in the first circuit member is 400 μm or more.