JP2016177917A - Circuit connection material and connection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit connection material excellent in electrical connection even when a first circuit member and a second circuit member having a protective layer are connected and the circuit connection material is arranged to overlap with the protective layer of the second circuit member.SOLUTION: There is provided a circuit connection material having an anisotropic conductive layer containing conductive particles and being belt like, where the anisotropic conductive layer has a belt like thick film part and a belt like thin film part neighboring in a width direction of the circuit connection material and the average thickness of the thin film part is 40% o 60% to the average thickness of the thin film part.SELECTED DRAWING: Figure 3B

Description

  The present invention relates to a circuit connection material 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.

  The anisotropic conductive film includes, for example, a terminal of a flexible printed circuit (FPC) or an IC (Integrated Circuit) chip, and an ITO (Indium Tin Oxide) electrode formed on a glass substrate of an LCD (Liquid Crystal Display) panel. It is used when various terminals are bonded and electrically connected to each other, starting with the case of connecting the terminals.

  Recently, for the purpose of narrowing the display panel, a connection portion between the display panel and the flexible printed board using the ACF is close to an end portion of the display panel. And the said flexible printed circuit board may be bent and used for the surface (back surface) side opposite to the said connection part side of the said display panel. At that time, in order to prevent the wiring on the flexible printed circuit board from coming into contact with the end of the display panel and being disconnected, a protective layer is provided on the flexible printed circuit board (see, for example, Patent Document 1). ).

JP 2002-358026 A

In the connection portion between the first circuit member such as the display panel and the second circuit member such as the flexible printed board using the circuit connection material which is the ACF, in order to increase the adhesive strength of the connection portion. In addition, the circuit connection material may be disposed so as to overlap the protective layer.
However, when the conventional circuit connection material is arranged so as to overlap the protective layer, there is a problem that the conductive particles in the circuit connection material in the connection portion are not sufficiently crushed and electrical connection becomes insufficient. .

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, according to the present invention, in the connection between the first circuit member and the second circuit member having the protective layer, the circuit connection material is disposed so as to overlap the protective layer of the second circuit member. An object of the present invention is to provide a circuit connection material excellent in electrical connection and a connection method using the same.

Means for solving the problems are as follows. That is,
<1> A circuit connection material having an anisotropic conductive layer containing conductive particles and having a strip shape,
The anisotropic conductive layer has a strip-shaped thick film portion and a strip-shaped thin film portion adjacent to the width direction of the circuit connecting material,
The circuit connection material is characterized in that an average thickness of the thin film portion is 40% to 60% with respect to an average thickness of the thick film portion.
<2> The circuit connection material according to <1>, wherein a width of the thin film portion with respect to a width of the anisotropic conductive layer is 30% to 50%.
<3> Furthermore, it has a release film,
The circuit connection material according to any one of <1> to <2>, wherein at least a part of the thin film portion and the thick film portion in the anisotropic conductive layer are arranged on the release film. .
<4> Furthermore, it has a 2nd peeling film on the opposite side to the said peeling film side of the said anisotropic conductive layer,
<3 where the second release film is disposed on the thin film portion of the thick film portion and the thin film portion in the anisotropic conductive layer and on at least a part of the thin film portion. > Is a circuit connecting material.
<5> The circuit connection material according to <4>, wherein the second release film, the thick film portion, and the thin film portion satisfy the following formula (1).
0 (μm) ≦ R− (AB) ≦ 18 (μm) Formula (1)
However, in said Formula (1), R represents the average thickness of a said 2nd peeling film, A represents the average thickness of the said thick film part, and B represents the average thickness of the said thin film part.
<6> A connection method for connecting a first circuit member having a terminal and a second circuit member having a protective layer and a terminal for protecting the wiring,
A first disposing step of disposing the anisotropic conductive layer in the circuit connection material according to any one of <1> to <5> on the terminal of the first circuit member;
On the anisotropic conductive layer, the second circuit is arranged such that the terminal of the second circuit member is in contact with the thick film portion and the protective layer of the second circuit member is in contact with the thin film portion. A second arrangement step of arranging the members;
And a heating and pressing step of heating and pressing the second circuit member with a heating and pressing member.

  According to the present invention, the conventional problems can be solved and the object can be achieved. In the connection between the first circuit member and the second circuit member having the protective layer, a circuit connection material is used. Even when it arrange | positions so that it may overlap with the said protective layer of a said 2nd circuit member, the circuit connection material excellent in electrical connection and the connection method using the same can be provided.

FIG. 1A is a schematic top view of an example of the circuit connection material of the present invention. FIG. 1B is a schematic cross-sectional view in the width direction of an example of the circuit connection material of the present invention, and is a cross-sectional view taken along line AA in FIG. 1A. FIG. 2A is a schematic top view of another example of the circuit connection material of the present invention. FIG. 2B is a schematic cross-sectional view in the width direction of another example of the circuit connection material of the present invention, and is a cross-sectional view taken along line AA in FIG. 2A. FIG. 3A is a schematic top view of another example of the circuit connection material of the present invention. FIG. 3B is a schematic cross-sectional view in the width direction of another example of the circuit connecting material of the present invention, and is a cross-sectional view taken along line AA in FIG. 3A. FIG. 4A is a schematic diagram for explaining an example of a method for producing a circuit connecting material according to the present invention (part 1). FIG. 4B is a schematic diagram for explaining an example of a method for producing a circuit connecting material of the present invention (part 2). FIG. 4C is a schematic diagram for explaining an example of a method for producing a circuit connecting material according to the present invention (part 3). FIG. 4D is a schematic diagram for explaining an example of a method for producing a circuit connecting material according to the present invention (part 4). FIG. 4E is the schematic for demonstrating an example of the manufacturing method of the circuit connection material of this invention (the 5). FIG. 5A is a schematic diagram for explaining an example of the connection method of the present invention (part 1). FIG. 5B is a schematic diagram for explaining an example of the connection method of the present invention (part 2). FIG. 5C is a schematic diagram for explaining an example of the connection method of the present invention (part 3). FIG. 5D is a schematic diagram for explaining an example of the connection method of the present invention (part 4). FIG. 5E is a schematic diagram for explaining an example of the connection method of the present invention (part 5). FIG. 5F is a schematic diagram for explaining an example of the connection method of the present invention (part 6). FIG. 5G is a schematic diagram for explaining an example of the connection method of the present invention (part 7).

(Circuit connection material)
The circuit connection material of this invention has an anisotropic conductive layer at least, Preferably, it has a peeling film and a 2nd peeling film, and also has another member as needed.
The circuit connection material has a strip shape. In other words, the strip shape is a rectangle, and is also referred to as a strip shape.

There is no restriction | limiting in particular as the width | variety of the said circuit connection material, According to the objective, it can select suitably, For example, 0.5 mm-5 mm etc. are mentioned.
There is no restriction | limiting in particular as the length of the said circuit connection material, According to the objective, it can select suitably, For example, 50m-200m etc. are mentioned in the state wound by the reel. Moreover, when removing and using from a reel, it is cut out to the length of 1 cm-10 cm, for example.

<Anisotropic conductive layer>
The anisotropic conductive layer contains at least conductive particles, and further contains other components such as a film-forming resin, a curable resin, and a curing agent as necessary.

  The anisotropic conductive layer has a strip-shaped thick film portion and a strip-shaped thin film portion adjacent to each other in the width direction of the circuit connecting material.

<< Thick film part >>
There is no restriction | limiting in particular as average thickness of the said thick film part, Although it can select suitably according to the objective, 5 micrometers-50 micrometers are preferable, and 10 micrometers-30 micrometers are more preferable.
The average thickness is an arithmetic average value when the thicknesses of arbitrary 10 locations are measured. The thickness can be measured, for example, by observation with a scanning electron microscope.

<< Thin film part >>
The average thickness of the thin film portion is 40% to 60% with respect to the average thickness of the thick film portion.
Even if the average thickness of the thin film portion is less than 40% or more than 60% with respect to the average thickness of the thick film portion, the conductive particles are not sufficiently crushed, and as a result, the electrical connection becomes insufficient.

  There is no restriction | limiting in particular as a width | variety of the said thin film part, Although it can select suitably according to the objective, 30%-50% are preferable with respect to the width | variety of the said anisotropic conductive layer. If the width of the thin film portion is less than 30% of the width of the anisotropic conductive layer, the resin component filled between terminals of circuit members such as FPC becomes excessive, and electrical connection is insufficient. If it exceeds 50%, the resin component filled between terminals of circuit members such as FPC may be insufficient, and electrical connection may be insufficient. When the width of the thin film portion is within a preferable range, it is advantageous in that a resin component filled between terminals of a circuit member such as an FPC is filled without excess and deficiency, and a stable electrical connection can be obtained.

<< 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 arithmetic average value of particle diameters arbitrarily measured for 10 conductive particles.
The particle diameter can be measured, for example, by observation with a scanning electron microscope.

  It is preferable that the conductive particles are uniformly dispersed in the thick film portion and the thin film portion in the anisotropic conductive layer.

  There is no restriction | limiting in particular as content of the said electroconductive particle in the said anisotropic conductive 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.

<< 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.

  It is preferable that the film forming resin is uniformly distributed in the thick film portion and the thin film portion in the anisotropic conductive layer.

  There is no restriction | limiting in particular as content of the said film formation resin in the said anisotropic conductive layer, Although it can select suitably according to the objective, 25 mass%-65 mass% are preferable, 35 mass%-55 mass% % Is more preferable.

<< Curable resin >>
There is no restriction | limiting in particular as said curable resin, According to the objective, it can select suitably, For example, an epoxy resin, an acrylate resin, 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.

-Acrylate resin-
The acrylate resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, epoxy acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylol Propane triacrylate, dimethylol tricyclodecane diacrylate, tetramethylene glycol tetraacrylate, 2-hydroxy-1,3-diaacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2, 2-bis [4- (acryloxyethoxy) phenyl] propane, dicyclopentenyl acrylate, tricyclodecanyl acrylate, tris (acryloxyethyl) i Cyanurates, such as urethane acrylate, and the like. These may be used individually by 1 type and may use 2 or more types together.
Moreover, what made the said acrylate into the methacrylate is mentioned, 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 curable resin in the said anisotropic conductive layer, Although it can select suitably according to the objective, 25 mass%-65 mass% are preferable, and 35 mass%-55 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 organic peroxide include lauroyl peroxide, butyl peroxide, benzyl peroxide, dilauroyl peroxide, dibutyl peroxide, peroxydicarbonate, dibenzoyl peroxide, and the like.
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.

  There is no restriction | limiting in particular as content of the said hardening | curing agent in the said anisotropic conductive layer, Although it can select suitably according to the objective, 1 mass%-10 mass% are preferable, 2 mass%-8 mass% Is more preferable.

  The combination of the curable resin and the curing agent is not particularly limited and may be appropriately selected depending on the purpose. The combination of the epoxy resin and the cationic curing agent, the acrylate resin and the organic A combination with a peroxide is preferred.

<Peeling film>
The release film is not particularly limited as long as it is a film having releasability, and can be appropriately selected according to the purpose. For example, it can be obtained by applying a release agent on a plastic film.

  When the circuit connection material has the release film, it is preferable that at least a part of the thin film portion and the thick film portion in the anisotropic conductive layer are arranged on the release film.

  Examples of the material of the plastic film include PET (Poly Ethylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methylpentene-1), and PTFE (Polytetrafluoroethylene).

  Examples of the release agent include silicone.

  There is no restriction | limiting in particular as average thickness of the said peeling film, According to the objective, it can select suitably.

<Second release film>
The circuit connection material preferably further includes a second release film on the opposite side of the anisotropic conductive layer to the release film side.

The second release film is preferably disposed on at least a part of the thin film portion on the thin film portion of the thick film portion and the thin film portion in the anisotropic conductive layer. .
By doing so, it is possible to prevent at least one of collapse and blocking in the winding quality when the circuit connecting material is wound on a reel.

In the circuit connection material, the second release film, the thick film portion, and the thin film portion preferably satisfy the following formula (1), and more preferably satisfy the formula (2).
0 (μm) ≦ R− (AB) ≦ 18 (μm) Formula (1)
0 (μm) ≦ R− (AB) ≦ 15 (μm) Formula (2)
However, in said Formula (1) and said Formula (2), R represents the average thickness of the said 2nd peeling film, A represents the average thickness of the said thick film part, B represents the said thin film part. Represents the average thickness.
When [R- (AB)] is less than 0 [mu] m, no winding collapse occurs when the circuit connecting material is wound around the reel. However, when the circuit connection material is wound around the reel, the binder of the thick film portion wraps around the surface of the second release film. As a result, when the circuit connection material is pulled out from the reel and the second release film is peeled off, the anisotropic conductive layer is pulled away from the release film simultaneously with the second release film, and blocking occurs. .
On the other hand, when [R- (AB)] exceeds 18 μm, blocking does not occur when the circuit connecting material is pulled out from the reel. However, when the circuit connection material is wound around the reel, the circuit connection material falls off the reel, and the winding collapses.
[R- (AB)] preferably satisfies the above formula (1) and more preferably satisfies the above formula (2) from the viewpoint of achieving both prevention of collapse and blocking.

  From the viewpoint of preventing blocking, the second release film is preferably a release film whose both surfaces have been release-treated.

  The second release film is not particularly limited as long as it is a film having releasability, and can be appropriately selected according to the purpose. For example, the second release film can be obtained by applying a release agent on a plastic film. There is no restriction | limiting in particular as said plastic film and said release agent, According to the objective, it can select suitably, For example, the said plastic film illustrated in description of the said release film, and the said release agent are each mentioned.

<Manufacturing method of circuit connection material>
The method for producing the circuit connection material is not particularly limited and may be appropriately selected depending on the intended purpose, but includes a film laminate production process, a cutting process, an arrangement process, and a pressing process, and is further necessary. Depending on the, it is preferable to include other steps.

<< Film Laminate Production Step >>
The film laminate production step is not particularly limited as long as it is a step of producing a film laminate in which a flat anisotropic conductive layer is formed by applying an anisotropic conductive composition on a release film. And can be appropriately selected according to the purpose.

-Anisotropic conductive composition-
The anisotropic conductive composition contains at least conductive particles, and further contains other components such as a film-forming resin, a curable resin, and a curing agent as necessary.
As these each component, each component illustrated in description of the said anisotropic conductive layer in the said circuit connection material is mentioned, for example.

  There is no restriction | limiting in particular as the method of the said application | coating, According to the objective, it can select suitably.

<< Cutting process >>
The cutting step is not particularly limited as long as it is a step of cutting the film laminate to obtain a strip-shaped film laminate, and can be appropriately selected according to the purpose.
There is no restriction | limiting in particular as the width | variety of the said strip | belt-shaped film laminated body, According to the objective, it can select suitably, For example, 0.5 mm-5 mm etc. are mentioned.

<< Placement process >>
As the arrangement step, a second strip-like release film is arranged along a longitudinal direction of the belt-like film laminate on a part of the surface of the flat anisotropic conductive layer in the belt-like film laminate. If it is a process to perform, there will be no restriction in particular and it can choose suitably according to the object.

  There is no restriction | limiting in particular as a material etc. of the said strip | belt-shaped 2nd peeling film, According to the objective, it can select suitably, For example, the said 1st illustrated in description of the said 2nd peeling film in the said circuit connection material The material of the release film of 2 is mentioned.

<< Pressing process >>
The pressing step is not particularly limited as long as it is a step of pressing the strip-shaped second release film and pressing the strip-shaped second release film into the flat anisotropic conductive layer, depending on the purpose. Can be selected as appropriate.

  The circuit connection material is manufactured through the above steps.

Here, an example of the circuit connection material of the present invention and the manufacturing method thereof will be described with reference to the drawings.
FIG. 1A is a schematic top view of an example of the circuit connection material of the present invention.
FIG. 1B is a schematic cross-sectional view in the width direction of an example of the circuit connection material of the present invention, and is a cross-sectional view taken along line AA in FIG. 1A.
1A and 1B has an anisotropic conductive layer 2 composed of a thick film portion 2A and a thin film portion 2B.
The thick film portion 2A and the thin film portion 2B are both strip-shaped.
The anisotropic conductive layer 2 has a thick film portion 2 </ b> A and a thin film portion 2 </ b> B adjacent to the width direction of the circuit connection material 1.

FIG. 2A is a schematic top view of another example of the circuit connection material of the present invention.
FIG. 2B is a schematic cross-sectional view in the width direction of another example of the circuit connection material of the present invention, and is a cross-sectional view taken along line AA in FIG. 2A.
2A and 2B includes a release film 3, an anisotropic conductive layer 2 including a thick film portion 2A and a thin film portion 2B, and a second release film 4.
The thick film portion 2A and the thin film portion 2B are both strip-shaped.
The anisotropic conductive layer 2 has a thick film portion 2 </ b> A and a thin film portion 2 </ b> B adjacent to the width direction of the circuit connection material 1.
The anisotropic conductive layer 2 is formed on the release film 3.
The 2nd peeling film 4 is arrange | positioned on the thin film part 2B.

FIG. 3A is a schematic top view of another example of the circuit connection material of the present invention.
FIG. 3B is a schematic cross-sectional view in the width direction of another example of the circuit connecting material of the present invention, and is a cross-sectional view taken along line AA in FIG. 3A.
3A and 3B includes a release film 3, an anisotropic conductive layer 2 including a thick film portion 2A and a thin film portion 2B, and a second release film 4.
The thick film portion 2A and the thin film portion 2B are both strip-shaped.
The anisotropic conductive layer 2 has a thick film portion 2 </ b> A and a thin film portion 2 </ b> B adjacent to the width direction of the circuit connection material 1.
The anisotropic conductive layer 2 is formed on the release film 3.
The 2nd peeling film 4 is arrange | positioned on the thin film part 2B.
A part of the thin film portion 2B protrudes from the release film 3.
A part of the second release film 4 protrudes from the thin film portion 2B.
The second release film 4 has the same thickness as the thick film portion 2A.

Next, an example of the method for producing the circuit connecting material of the present invention will be described with reference to FIGS. 4A to 4B.
First, an anisotropic conductive composition is applied on the release film 3 to produce a flat anisotropic conductive layer 2C (FIGS. 4A and 4B). 4B is a cross-sectional view taken along the line AA in FIG. 4A. Here, the release film 3 has a strip shape.
Next, the 2nd peeling film 4 is arrange | positioned along the longitudinal direction of the peeling film 3 in a part of surface of the flat anisotropic conductive layer 2C (FIG. 4C and FIG. 4D). 4D is a cross-sectional view taken along the line AA in FIG. 4C. Here, the 2nd peeling film 4 is strip | belt shape.
Next, the second release film 4 is pressed, and the second release film 4 is pressed into the flat anisotropic conductive layer 2C. By doing so, the thick film portion 2A and the thin film portion 2B are formed from the flat anisotropic conductive layer 2C.
As a result, a circuit connection material as shown in FIG. 4E is obtained.

(Connection method)
The connection method of 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 a first circuit member having a terminal and a second circuit member having a protective layer and a terminal for protecting the wiring.

<First circuit member>
The first circuit member is not particularly limited as long as it is a circuit member that has terminals and is an object of anisotropic conductive connection using the circuit connection material, and can be appropriately selected according to the purpose. For example, a glass substrate having terminals, a plastic substrate having terminals, IC (Integrated Circuit), TAB (Tape Automated Bonding) tape, Flex-on-Glass (Flex-on-glass, FOG), Chip-on-Glass (chip) On-glass, COG), Chip-on-Flex (chip-on-flex, COF), Flex-on-Board (flex-on-board, FOB), Flex-on-Flex (flex-on-flex, FOF), liquid crystal panels, etc. It is done.

<Second circuit member>
The second circuit member is not particularly limited as long as it is a circuit member that has a protective layer and a terminal and is an object of anisotropic conductive connection using the circuit connection material, and is appropriately selected according to the purpose. For example, a glass substrate having terminals, a plastic substrate having terminals, IC (Integrated Circuit), TAB (Tape Automated Bonding) tape, Flex-on-Glass (Flex-on-glass, FOG), Chip-on- Glass (chip-on-glass, COG), Chip-on-Flex (chip-on-flex, COF), Flex-on-Board (flex-on-board, FOB), Flex-on-Flex (flex-on-flex, FOF), liquid crystal panel Etc.

  The protective layer in the second circuit member is not particularly limited as long as the wiring in the second circuit member is protected, and can be appropriately selected according to the purpose. Examples thereof include an insulating resin layer. It is done. The insulating resin layer can be formed, for example, by applying a solder resist.

  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.

<First arrangement step>
The first disposing step is not particularly limited as long as it is a step of disposing the anisotropic conductive layer in the circuit connecting material on the terminal of the first circuit member. You can choose.

  In the first arrangement step, the anisotropic conductive layer arranged on the terminal of the first circuit member may be only the thick film part, or the thick film part and the thin film part. It may be.

<Second arrangement step>
In the second disposing step, the terminal of the second circuit member is in contact with the thick film portion on the anisotropic conductive layer, and the protective layer in the second circuit member is in contact with the thin film portion. If it is the process of arrange | positioning the said 2nd circuit member so that it may contact, there will be no restriction | limiting in particular, According to the objective, it can select suitably.

<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.

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.

(Joint)
The joined body according to the present invention includes at least a first circuit member, a second circuit member, and a cured product of the circuit connection material, and further includes other members as necessary.

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

Here, an example of the connection method of the present invention will be described with reference to the drawings.
5A to 5G are schematic views for explaining an example of the connection method of the present invention.
First, a first circuit member 11 as shown in FIGS. 5A and 5B is prepared. The first circuit member 11 includes a substrate 11A, a display panel unit 11B, an integrated circuit 11C, and a terminal 11D. The display panel unit 11B, the integrated circuit 11C, and the terminal 11D are formed on the substrate 11A and are connected by wiring (not shown). The terminal 11D is formed at the end of the substrate 11A. Here, FIG. 5A is a top view and FIG. 5B is a cross-sectional view.

Next, a circuit connection material 1 shown in FIG. 4E is prepared. Then, the second release film 4 is peeled from the circuit connection material 1. Then, as shown in FIG. 5C, the circuit connecting material having the anisotropic conductive layer 2 and the release film 3 on the terminal 11 </ b> D of the first circuit member 11 is replaced with the thick film portion of the anisotropic conductive layer 2. It arrange | positions so that 2A may contact the terminal 11D.
Then, as shown in FIG. 5D (sectional view) and FIG. 5E (top view), the release film 3 is peeled from the anisotropic conductive layer 2.

Next, the second circuit member 12 (FIG. 5F) is prepared. The second circuit member 12 includes a substrate 12A, a terminal 12B, and a protective layer 12C. The terminal 12B and the protective layer 12C are formed on the substrate 12A. The terminal 12B is formed at the end of the substrate 12A. The protective layer 12C protects wiring (not shown).
As shown in FIG. 5F, the terminal 12B of the second circuit member 12 is in contact with the thick film portion 2A and the protective layer 12C of the second circuit member 12 is in contact with the thin film portion 2B on the anisotropic conductive layer. In this manner, the second circuit member 12 is arranged.

  Next, as illustrated in FIG. 5G, the terminal 11 </ b> D and the terminal 12 </ b> B are connected to each other by the circuit connecting material 1 by heating and pressing the second circuit member 12 with a heating pressing member (not illustrated).

  At this time, the anisotropic conductive layer 2 in the circuit connecting material 1 has the thick film portion 2A and the thin film portion 2B, so that the anisotropic conductive layer 2 in which the second circuit member 12 has the protective layer 12C. Insufficiency can be prevented and a good connection can be made.

  5G, the second circuit member 12 is bent at the end on the terminal 11D side of the first circuit member 11, and the end opposite to the end on the terminal 12B side of the second circuit member 12 The portion may be folded on the opposite side of the first circuit member 11 from the display panel portion 11B side.

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

Example 1
<Production of circuit connection material>
The following formulations were mixed uniformly to prepare a mixture.
-Formulation-
Phenoxy resin (Product name: jER4256, manufactured by Mitsubishi Chemical Corporation) 46 parts by mass Urethane acrylate (Product name: U-2PPA, manufactured by Shin-Nakamura Chemical Co., Ltd.) 25 parts by mass Bifunctional acrylate (Product name: A-200, manufactured by Shin-Nakamura Chemical Co., Ltd.) 20 Part by mass Phosphate ester acrylate (Product name: PM-2, manufactured by Nippon Kayaku Co., Ltd.) 1 part by mass Conductive particles (Product name: AUL704, manufactured by Sekisui Chemical Co., Ltd.) 2 parts by mass Dilauroyl peroxide 3 parts by mass Dibenzoylper 3 parts by mass of oxide

  The obtained mixture was coated on a polyester film (release film) so that the average thickness after drying was 25 μm, dried by blowing hot air at 70 ° C. for 5 minutes, and flat anisotropy was formed on the release film. A film laminate in which a conductive layer (flat AC layer) was formed was obtained.

Next, the film laminate is cut into a width of 2.0 mm, and then a spacer film (SF: second release film) having the same width as the cut width and an average thickness of 25 μm is cut into the cut width of the film laminate ( 2.0 mm) is laminated so as to cover 50% (wrap width: 1.0 mm), heated and pressurized by heat lamination at 60 ° C., and a spacer film is buried in 10 μm of the anisotropic conductive layer and wound on a plastic reel. Thus, a wound body of the circuit connecting material was obtained.
The spacer film used was a film whose both surfaces were release-treated.

<Manufacture of joined body>
The joined body was manufactured by the following method.
<< FPC >>
The following A and B were prepared as evaluation flexible printed circuit boards (evaluation FPC).

  The protective layer was formed from a solder resist.

<< Display panel >>
Aluminum vapor-deposited glass was used as a display panel for evaluation.

The spacer film was peeled from the wound body, and the circuit connection material from which the spacer film was peeled was disposed on the edge side of the aluminum vapor-deposited glass so that the anisotropic conductive layer was in contact with the aluminum vapor-deposited glass.
By pressing a pressure-bonding head having a width of 2.0 mm against the upper surface of the release film through a buffer material (silicon rubber) having a thickness of 200 μm, and heating and pressurizing the film laminate under the conditions of 80 ° C., 1 MPa, and 1 second. The anisotropic conductive layer was affixed on the aluminum vapor-deposited glass.
The release film was peeled off and placed on the anisotropic conductive layer so that the protective layer of the evaluation FPC (A) overlapped by 100 μm.
Through a buffer material (silicon rubber) having a thickness of 200 μm, the pressing position of a 2.0 mm-wide crimping head is aligned with the edge of the aluminum-deposited glass, and from the FPC (A) side for evaluation, 160 ° C., 3 MPa, The aluminum vapor-deposited glass and the evaluation FPC (A) were connected by heating and pressurizing for 2 seconds to obtain a joined body.

<Evaluation>
The following evaluation was performed about the produced joined_body | zygote. The results are shown in Table 2-1.

<< Connection status >>
A metal microscope (manufactured by Olympus Co., Ltd., trade name: MX51) was used, and the observation was performed by a differential interference observation method in which a differential interference prism and a polarizing plate were attached for observation.
Of the width from the position where the particle trace was observed on the end side of the FPC for evaluation to the end of the protective layer (the effective crimping width), the width where the particle trace was observed was measured and evaluated according to the following evaluation criteria. did.
〔Evaluation criteria〕
○: The width in which the particle trace was observed is 90% or more on the average of the effective crimping width Δ: The width in which the particle trace was observed is 80% to less than 90% on the average in the effective crimping width ×: The width in which the particle trace was observed was crimped The average effective width is less than 80% Here, the particle mark means the conductive particles in a crushed state.

<< Evaluation of winding quality >>
When obtaining the wound body of the circuit connection material, the circuit connection material having a width of 2.0 mm and a length of 100 m was wound around a reel having a core diameter of 55 mm with a tension of 0.2 N / mm ² . Then, a weight of 50 g was left hanging on the circuit connecting material at the end of the wound body in a 30 ° C. environment.
The collapse was confirmed by appearance observation.
Moreover, the circuit connection material was pulled out from the reel, the spacer film was peeled off, and the presence or absence of peeling (blocking) of the anisotropic conductive layer from the peeling film was confirmed.
The evaluation criteria are shown below.

[Evaluation criteria for rollover]
○: No collapse of the circuit connection material occurred.
(Triangle | delta): The spacer film or the binder of the anisotropic conductive layer contacted the reel flange.
X: The circuit connecting material dropped from the reel and collapsed.

[Evaluation criteria for blocking]
○: Blocking did not occur.
X: Blocking occurred.

(Examples 2 to 15 and Comparative Examples 1 to 6)
In Example 1, the average thickness of the spacer film, the buried depth of the spacer film, the wrap width of the spacer film, the average thickness of the thick film portion in the anisotropic conductive layer, and the average thickness of the thin film portion in the anisotropic conductive layer, And the winding body of the circuit connection material was produced like Example 1 except having changed the kind of FPC for evaluation as described in Table 2-1-Table 2-3.
About the obtained circuit connection material, evaluation similar to Example 1 was performed. The results are shown in Tables 2-1 to 2-3.

Here, the buried depth of the spacer film (SF) represents the depth at which the spacer film is buried with respect to the flat anisotropic conductive layer, and the difference between the average thickness of the thick film portion and the average thickness of the thin film portion. Corresponding to The ratio corresponds to 1- (average thickness of thick film portion / average thickness of thin film portion).
The wrap width of the spacer film (SF) corresponds to the width of the thin film portion, and the ratio corresponds to the ratio of the width of the thin film portion to the width of the anisotropic conductive layer.

In Examples 1 to 15, the anisotropic conductive layer has a thick film part and a thin film part, and the average thickness of the thin film part with respect to the average thickness of the thick film part is 40% to 60%. Even when the circuit member has a protective layer, a good connection state was obtained.
On the other hand, in Comparative Example 3, since the anisotropic conductive layer did not have the thick film portion and the thin film portion, the connection state was insufficient.
In Comparative Examples 1, 2, 4 to 6, even if the anisotropic conductive layer has a thick film portion and a thin film portion, the average thickness of the thin film portion with respect to the average thickness of the thick film portion is If it is less than 40% or more than 60%, the connection state was insufficient.

  Moreover, when satisfy | filling said Formula (1), it was excellent in coexistence with prevention of collapse and prevention of blocking, and satisfying said Formula (2) was more excellent in coexistence of prevention of collapse and prevention of blocking.

  The circuit connection material of the present invention can be suitably used for electrical connection of a circuit member having a protective layer.

DESCRIPTION OF SYMBOLS 1 Circuit connection material 2 Anisotropic conductive layer 2A Thick film part 2B Thin film part 2C Flat anisotropic conductive layer 3 Peeling film 4 2nd peeling film 11 1st circuit member 11A Board | substrate 11B Display panel part 11C Integrated circuit 11D Terminal 12 Second circuit member 12A Substrate 12B Terminal 12C Protective layer

Claims (6)

A circuit connecting material having an anisotropic conductive layer containing conductive particles and having a strip shape,
The anisotropic conductive layer has a strip-shaped thick film portion and a strip-shaped thin film portion adjacent to the width direction of the circuit connecting material,
The circuit connection material, wherein an average thickness of the thin film portion with respect to an average thickness of the thick film portion is 40% to 60%.   The circuit connection material according to claim 1, wherein a width of the thin film portion with respect to a width of the anisotropic conductive layer is 30% to 50%. Furthermore, it has a release film,
The circuit connection material according to claim 1, wherein at least a part of the thin film portion and the thick film portion in the anisotropic conductive layer are arranged on the release film. Furthermore, it has a second release film on the side opposite to the release film side of the anisotropic conductive layer,
The said 2nd peeling film is distribute | arranged on the said thin film part of the said thick film part and the said thin film part in the said anisotropic conductive layer, Comprising: At least one part of the said thin film part is distribute | arranged. Circuit connection material described in 1. The circuit connection material according to claim 4, wherein the second release film, the thick film portion, and the thin film portion satisfy the following expression (1).
0 (μm) ≦ R− (AB) ≦ 18 (μm) Formula (1)
However, in said Formula (1), R represents the average thickness of a said 2nd peeling film, A represents the average thickness of the said thick film part, and B represents the average thickness of the said thin film part. A connection method for connecting a first circuit member having a terminal, a protective layer for protecting a wiring, and a second circuit member having a terminal,
A first disposing step of disposing the anisotropic conductive layer in the circuit connection material according to any one of claims 1 to 5 on the terminal of the first circuit member;
On the anisotropic conductive layer, the second circuit is arranged such that the terminal of the second circuit member is in contact with the thick film portion and the protective layer of the second circuit member is in contact with the thin film portion. A second arrangement step of arranging the members;
And a heating and pressing step of heating and pressing the second circuit member with a heating and pressing member.