JP2017098413A - Repair method and connection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection method with excellent repairability.SOLUTION: A connection method comprises: a temporal adhesion step; an arrangement step; a heating pressing step; and a repairing step of, when a displacement occurs at a fixed position of a thermal hardening type anisotropic conductive film fixed onto a first circuit member by the temporal adhesion step, performing a light irradiation to the thermal hardening type anisotropic conductive film through an adhesion tape, hardening the thermal hardening type anisotropic conductive film with a light, and further pealing the adhesion tape from the first circuit member with the thermal hardening type anisotropic conductive film after the adhesion tape is adhered to the thermal hardening type anisotropic conductive film.SELECTED DRAWING: Figure 1

Description

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

  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 starts, for example, when connecting a terminal of a flexible printed circuit (FPC) or IC (Integrated Circuit) chip and an electrode formed on a glass substrate of an LCD (Liquid Crystal Display) panel. In other words, it is used when various terminals are bonded and electrically connected.

  In the connection method using such an anisotropic conductive film, a temporary pasting step is usually performed in which the anisotropic conductive film is temporarily pressed and fixed to the substrate. And when the malfunction has arisen in the fixed position of the anisotropic conductive film after temporary crimping, the repair process which removes an anisotropic conductive film and carries out temporary crimping again is performed.

  In particular, with recent miniaturization and higher performance of electrical devices, the fine pitch of electrodes has been promoted in electronic components and substrates, but good connection reliability is also achieved in the fine pitch connection between electronic components and substrates. It is required to obtain high connection reliability while securing the above.

  Here, in the case of fine pitch connection, since the connection area becomes extremely small, the occurrence of temporary crimping position shift also increases in the temporary bonding process of the anisotropic conductive film. The repair process to peel off is also increasing. If the anisotropic conductive film can be mechanically peeled off and the surface of the wiring board can be cleaned even after the temporary attachment, the wiring board can be reused when a problem occurs. However, the anisotropic conductive film in the temporary press bonding stage does not have sufficient mechanical strength, and cannot be peeled off smoothly by being cut during the peeling.

Therefore, a first placement step of placing the adhesive film on the wiring board, a temporary crimping step of fixing the adhesive film on the wiring board by heating at a temperature at which the adhesive film is not thermally cured, and fixing on the wiring board When there is no deviation in the fixing position of the adhesive film, the second placement step of placing the electronic member on the adhesive film and the electronic member placed on the adhesive film are thermally pressed to cure the adhesive film. And a main crimping step for crimping the wiring board and the electronic member, and when the fixing position of the adhesive film fixed on the wiring board is shifted in the temporary crimping step, the adhesive film is cured by light irradiation. Then, a connection method has been proposed that includes a repair process in which the adhesive film is peeled off from the wiring board and the wiring board is returned to the first arrangement process (see, for example, Patent Document 1).
However, this proposed technique has a problem that repairability is not sufficient.

JP 2014-096531 A

  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 repair method excellent in repairability, and a connection method including the repair method and excellent repairability.

Means for solving the problems are as follows. That is,
<1> A connection method for anisotropically connecting a terminal of a first circuit member and a terminal of a second circuit member,
A thermosetting anisotropic conductive film is disposed on a terminal of the first circuit member, and the thermosetting anisotropic conductive film is heated at a temperature at which the thermosetting anisotropic conductive film is not thermoset while pressing the thermosetting anisotropic conductive film. A temporary pasting step of heating and fixing the thermosetting anisotropic conductive film on the first circuit member;
When there is no shift in the fixing position of the thermosetting anisotropic conductive film fixed on the first circuit member by the temporary pasting step, the thermosetting anisotropic conductive film is An arrangement step of arranging a second circuit member so that a terminal of the second circuit member is in contact with the thermosetting anisotropic conductive film;
A heating and pressing step of heating and pressing the second circuit member with a heating and pressing member,
When there is a shift in the fixing position of the thermosetting anisotropic conductive film fixed on the first circuit member by the temporary pasting step, an adhesive tape is applied to the thermosetting anisotropic conductive film. Then, the thermosetting anisotropic conductive film is irradiated with light through the adhesive tape, the thermosetting anisotropic conductive film is photocured, and further from the first circuit member, A repair step of peeling the adhesive tape together with the thermosetting anisotropic conductive film,
It is the connection method characterized by this.
<2> The connection method according to <1>, wherein the thermosetting anisotropic conductive film contains a photocuring agent.
<3> The connection method according to any one of <1> to <2>, wherein the adhesive layer of the adhesive tape is photocurable.
<4> The connection method according to any one of <1> to <3>, wherein the thermosetting anisotropic conductive film is a radical curable anisotropic conductive film.
<5> The connection method according to any one of <1> to <4>, wherein the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape is photoradical curable.
<6> After sticking the adhesive tape to the thermosetting anisotropic conductive film fixed on the first circuit member by the temporary sticking step, light is applied to the thermosetting anisotropic conductive film through the adhesive tape. Irradiation, photocuring the thermosetting anisotropic conductive film, and further repairing the adhesive tape together with the thermosetting anisotropic conductive film from the first circuit member,
The temporary pasting step includes disposing the thermosetting anisotropic conductive film on a terminal of the first circuit member, and pressing the thermosetting anisotropic conductive film while pressing the thermosetting anisotropic conductive film. Heating the film at a temperature at which the film is not thermally cured, and fixing the thermosetting anisotropic conductive film on the first circuit member.
It is the repair method characterized by this.
<7> The repair method according to <6>, which is performed when a shift occurs in a fixing position of the thermosetting anisotropic conductive film fixed on the first circuit member by the temporary sticking step. It is.
<8> The repair method according to any one of <6> to <7>, wherein the thermosetting anisotropic conductive film contains a photocuring agent.
<9> The repair method according to any one of <6> to <8>, wherein the adhesive layer of the adhesive tape is photocurable.
<10> The repair method according to any one of <6> to <9>, wherein the thermosetting anisotropic conductive film is a radical curable anisotropic conductive film.
<11> The repair method according to any one of <6> to <10>, wherein the adhesive layer of the adhesive tape is photoradical curable.

  ADVANTAGE OF THE INVENTION According to this invention, the said various problems in the past can be solved, the said objective can be achieved, and the repair method which is excellent in repair property, and the connection method which is excellent in repair property including the said repair method can be provided.

FIG. 1 is a flowchart for explaining an example of the connection method of the present invention. FIG. 2A is a schematic cross-sectional view for explaining an example of a connection method of the present invention (part 1). FIG. 2B is a schematic cross-sectional view for explaining an example of the connection method of the present invention (part 2). FIG. 2C is a schematic cross-sectional view for explaining an example of the connection method of the present invention (part 3). FIG. 2D is a schematic cross-sectional view for explaining an example of the connection method of the present invention (part 4). FIG. 2E is a schematic cross-sectional view for explaining an example of the connection method of the present invention (part 5). FIG. 2F is a schematic cross-sectional view for explaining an example of the connection method of the present invention (No. 6). FIG. 2G is a schematic cross-sectional view for explaining an example of the connection method of the present invention (No. 7). FIG. 2H is a schematic cross-sectional view for explaining an example of the connection method of the present invention (No. 8). FIG. 2I is a schematic cross-sectional view for explaining an example of the connection method of the present invention (No. 9).

(Connection method)
The connection method of the present invention includes a temporary sticking step, an arrangement step, a heating and pressing step, and a repair step, and further includes other steps such as a misalignment determination step as necessary.
The connection method is a method in which the terminal of the first circuit member and the terminal of the second circuit member are anisotropically conductively connected.

<First circuit member, 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. , Can be appropriately selected according to the purpose, for example, a glass substrate having a terminal, a plastic substrate having a terminal, 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) Flex, FOF), liquid crystal panel, etc. And the like.

Examples of the glass substrate having the terminal include an ITO (Indium Tin Oxide) glass substrate, an IZO (Indium Zinc Oxide) glass substrate, and other glass pattern substrates. Among these, an ITO glass substrate and an IZO glass substrate are preferable.
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 substrate which has a terminal, the flexible substrate which has a terminal, etc. are mentioned.
Examples of the IC include a liquid crystal screen control IC chip in a flat panel display (FPD).

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.

<Temporary sticking process>
A thermosetting anisotropic conductive film is disposed on a terminal of the first circuit member, and the thermosetting anisotropic conductive film is heated at a temperature at which the thermosetting anisotropic conductive film is not thermoset while pressing the thermosetting anisotropic conductive film. If it is the process of heating and fixing the thermosetting anisotropic conductive film on the first circuit member, there is no particular limitation and it can be appropriately selected according to the purpose.

<< Thermosetting anisotropic conductive film >>
The thermosetting anisotropic conductive film is not particularly limited as long as it is an anisotropic conductive film that is cured by heating and used for connection by heating, and can be appropriately selected according to the purpose. it can.

The thermosetting anisotropic conductive film contains, for example, at least a film-forming resin, a curable resin, a thermosetting agent, and conductive particles, and further contains other components as necessary.
The thermosetting anisotropic conductive film preferably contains a photocuring agent.

  The thermosetting anisotropic conductive film is preferably a radical curable anisotropic conductive film.

-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 thermosetting anisotropic conductive film, Although it can select suitably according to the objective, 20 mass%-70 mass% are preferable, and 30 mass% -60 mass% is more preferable.

-Curable resin-
There is no restriction | limiting in particular as said curable resin (curing component), According to the objective, it can select suitably, For example, a radically polymerizable compound, an epoxy resin, etc. are mentioned.

--Radically polymerizable compound--
The radical polymerizable compound 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, Trimethylolpropane triacrylate, dimethyloltricyclodecane 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) Isocyanurate, and urethane acrylate. 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.

--- 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.

  There is no restriction | limiting in particular as content of the said curable resin in the said thermosetting anisotropic conductive film, Although it can select suitably according to the objective, 20 mass%-70 mass% are preferable, and 30 mass% -60 mass% is more preferable.

-Thermosetting agent-
The thermosetting agent is not particularly limited as long as it has an effect of curing the curable resin by heat, and can be appropriately selected according to the purpose. For example, a thermal radical curing agent, a thermal cationic curing agent Etc.

--- Heat radical curing agent--
There is no restriction | limiting in particular as said thermal radical type | system | group hardening | curing agent, According to the objective, it can select suitably, For example, an organic peroxide etc. are mentioned.
Examples of the organic peroxide include lauroyl peroxide, butyl peroxide, dilauroyl peroxide, dibutyl peroxide, peroxydicarbonate, and benzoyl peroxide.
The thermal radical curing agent is preferably used in combination with a radical polymerizable compound as the curable resin.

--Thermal cationic curing agent--
There is no restriction | limiting in particular as said thermal cationic hardening | curing agent, According to the objective, it can select suitably, For example, a sulfonium salt, onium salt, etc. are mentioned. Among these, aromatic sulfonium salts are preferable.
The thermal cationic curing agent is preferably used in combination with an epoxy resin as the curable resin.

  There is no restriction | limiting in particular as content of the said thermosetting agent in the said thermosetting anisotropic conductive film, According to the objective, it can select suitably, 1 mass%-10 mass% are preferable, and 3 mass%- 7 mass% is more preferable.

-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-30 micrometers are more preferable, and 3 micrometers-15 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 thermosetting type anisotropic conductive film, Although it can select suitably according to the objective, 0.5 mass%-10 mass% are preferable, and 3 A mass% to 8 mass% is more preferable.

-Light curing agent-
The photocuring agent is not particularly limited as long as it has an action of curing the curable resin with light, and can be appropriately selected according to the purpose. For example, a photoradical curing agent or a photocationic curing agent. Etc.

-Photo radical curing agent-
The photo radical curing agent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include acylphosphine oxide photo radical curing agents, acetophenone photo radical curing agents, and ketal photo radical curing agents. Etc. These are so-called photopolymerization initiators that generate radical active species upon irradiation with active energy rays such as ultraviolet rays.
Examples of the acyl phosphine oxide photo radical curing agent include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, Bis 4- (2,4,6-trimethylbenzoyl) -phenylphosphine oxide and the like can be mentioned.
Examples of the acetophenone photoradical curing agent include α-hydroxy-α, α'-dimethylacetophenone, methoxyacetophenone, 2,2-dimethoxy-2-phenylacetone, 2-hydroxy-2-cyclohexylacetophenone, and the like. .
Examples of the ketal photo radical curing agent include benzyl dimethyl ketal.
The photo radical curing agent is preferably used in combination with a radical polymerizable compound as the curable resin.

--Photocationic curing agent--
There is no restriction | limiting in particular as said photocationic hardening | curing agent, According to the objective, it can select suitably, For example, a sulfonium salt, an iodonium salt, etc. are mentioned. Among these, aromatic sulfonium salts are preferable.
The photocationic curing agent is preferably used in combination with an epoxy resin as the curable resin.

  In addition, a sulfonium salt, an iodonium salt, etc. may have the effect | action which hardens the said curable resin by both heat and light. That is, the thermal cationic curing agent may also be used as the photocationic curing agent.

There is no restriction | limiting in particular as content of the said photocuring agent in the said thermosetting anisotropic conductive film, Although it can select suitably according to the objective, 0.1 mass%-5 mass% are preferable, 0 More preferably, the content is 2% by mass to 3% by mass, and particularly preferably 0.3% by mass to 2% by mass.
Further, the content of the photocuring agent in the thermosetting anisotropic conductive film is not particularly limited and can be appropriately selected according to the purpose, but with respect to 100 parts by mass of the curable resin, 0.2 mass part-10 mass parts are preferable, 0.4 mass part-6 mass parts are more preferable, and 0.6 mass part-4 mass parts are especially preferable.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a silane coupling agent etc. are mentioned.

--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, According to the objective, it can select suitably.

There is no restriction | limiting in particular as average thickness of the said thermosetting anisotropic conductive film, Although it can select suitably according to the objective, 1 micrometer-50 micrometers are preferable, 5 micrometers-40 micrometers are more preferable, and 10 micrometers-30 micrometers are especially. preferable.
Here, the average thickness in this specification is an arithmetic average value when 10 arbitrary positions are measured.

In the temporary sticking step, the thermosetting anisotropic conductive film is heated at a temperature at which the thermosetting anisotropic conductive film is not thermoset while pressurizing the thermosetting anisotropic conductive film.
There is no restriction | limiting in particular as said pressurization pressure, According to the objective, it can select suitably, For example, 0.1 MPa-10 MPa etc. are mentioned.
Examples of the heating temperature include 70 ° C. to 100 ° C. This temperature may be determined with reference to the thermal decomposition temperature of the thermosetting agent of the thermosetting anisotropic conductive film.
Examples of the pressurizing and heating time include 0.5 seconds to 10 seconds.

<Arrangement process>
The placement step is a step of placing the second circuit member on the thermosetting anisotropic conductive film so that the terminals of the second circuit member are in contact with the anisotropic conductive film. There is no particular limitation, and it can be appropriately selected according to the purpose.

  The arrangement step is performed when there is no deviation in the fixing position of the thermosetting anisotropic conductive film fixed on the first circuit member by the temporary sticking step.

<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 the temperature of the said heating, Although it can select suitably according to the objective, 150 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-50 MPa are preferable.
There is no restriction | limiting in particular as time of the said heating and press, According to the objective, it can select suitably, For example, 0.5 second-120 second is mentioned.

<Repair process>
As the repair process, after sticking an adhesive tape to the thermosetting anisotropic conductive film, the thermosetting anisotropic conductive film is irradiated with light through the adhesive tape, and the thermosetting anisotropic The conductive conductive film is photocured, and there is no particular limitation as long as it is a step of peeling the adhesive tape together with the thermosetting anisotropic conductive film from the first circuit member. be able to.

  The repair process is performed when there is a shift in the fixing position of the thermosetting anisotropic conductive film fixed on the first circuit member by the temporary sticking process.

  The adhesive tape is preferably attached to the entire surface of the thermosetting anisotropic conductive film.

<< Adhesive tape >>
The adhesive tape is not particularly limited as long as it is an adhesive tape, and can be appropriately selected according to the purpose. For example, the adhesive tape includes a light-transmitting substrate and an adhesive layer.

-Light transmissive substrate-
The light-transmitting substrate is not particularly limited as long as it can transmit the light irradiated in the repair process, and can be appropriately selected according to the purpose. Examples thereof include a polyethylene terephthalate film.
Examples of the average thickness of the light transmissive substrate include 10 μm to 50 μm.

-Adhesive layer-
The adhesive layer is not particularly limited as long as it has adhesiveness, and can be appropriately selected according to the purpose. For example, an acrylic resin, a crosslinking agent, preferably a curable resin, and a photocuring agent. And, if necessary, other components such as a tackifier.

  The adhesive layer is preferably photocurable, and more preferably photoradical curable.

--Acrylic resin--
If it is resin which can be used as an adhesive as said acrylic resin, there will be no restriction | limiting in particular, According to the objective, it can select suitably, For example, a hydroxyl group and a carboxyl group-containing acrylic resin etc. are mentioned.

-Crosslinking agent-
The crosslinking agent is not particularly limited as long as it has an effect of curing the acrylic resin by heat, and can be appropriately selected according to the purpose. For example, polyisocyanate compound, polyepoxy compound, polyaziridine compound, melamine Formaldehyde condensates, metal salts, metal chelate compounds and the like can be mentioned.

  Examples of the polyisocyanate compound include aromatic polyisocyanate compounds, aliphatic or alicyclic polyisocyanate compounds, dimers or trimers of these polyisocyanate compounds, and polyisocyanate compounds and polyols such as trimethylolpropane. Examples thereof include adducts with compounds.

--Curable resin--
There is no restriction | limiting in particular as said curable resin, According to the objective, it can select suitably, For example, the radically polymerizable compound etc. which were mentioned by description of the said thermosetting anisotropic conductive film are mentioned.

--Photocuring agent--
The photo-curing agent is not particularly limited as long as it has an action of curing the curable resin with light, and can be appropriately selected according to the purpose. For example, description of the thermosetting anisotropic conductive film And the photo-radical curing agent mentioned in the above.

<< light irradiation >>
The light used for the light irradiation is not particularly limited as long as the thermosetting anisotropic conductive film is photocured, and can be appropriately selected according to the purpose, but ultraviolet light is preferable.
There is no restriction | limiting in particular as the irradiation amount of the said light, According to the objective, it can select suitably.
When the thermosetting anisotropic conductive film is photocured, the film strength is increased, and when the thermosetting anisotropic conductive film is peeled off together with the adhesive tape, the thermosetting anisotropic conductive film is torn off and becomes the first circuit member. It can be prevented from remaining.

  The light irradiation is performed through the adhesive tape. At this time, if the adhesive layer of the adhesive tape is photocurable, the adhesive layer of the adhesive tape is also photocured.

  The pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape is preferably photocurable. More preferably, the photocuring type of the thermosetting anisotropic conductive film and the photocuring type of the adhesive layer are the same. That is, when the photocurable type of the thermosetting anisotropic conductive film is a radical curable type, it is more preferable that the photocurable type of the adhesive layer is also a radical curable type. By doing so, the adhesiveness of the said thermosetting anisotropic conductive film and the said adhesion layer becomes larger after light irradiation, and repair property is more excellent.

<Position displacement determination process>
The position shift determination step is not particularly limited as long as it is a step for determining whether or not a shift occurs in the fixed position of the thermosetting anisotropic conductive film fixed on the first circuit member. However, it can be appropriately selected according to the purpose, and for example, it can be performed by image recognition using a camera.
In the positional deviation determination step, for example, a predetermined value within a preset allowable range is compared with a measured value, and it is determined that a positional deviation has occurred when the measured value exceeds the predetermined value.

  Here, the connection method of the present invention will be described with reference to the drawings. FIG. 1 is a flowchart for explaining an example of the connection method of the present invention. 2A to 2I are schematic cross-sectional views for explaining an example of the connection method of the present invention.

  First, the first circuit member 1 is prepared (FIG. 2A). The first circuit member 1 has a terminal 1A.

[Temporary sticking process]
Next, the thermosetting anisotropic conductive film 2 is disposed on the terminal 1A of the first circuit member 1 (FIG. 2B).
Next, the thermosetting anisotropic conductive film 2 is heated at a temperature at which the thermosetting anisotropic conductive film 2 is not thermoset while pressurizing the thermosetting anisotropic conductive film 2, and is applied onto the first circuit member 1. 2 is fixed (FIG. 2C).

[Position deviation determination process]
Next, it is determined whether or not there is a shift in the fixing position of the thermosetting anisotropic conductive film 2 fixed on the first circuit member 1 by the temporary pasting step.

[Placement process]
Next, when there is no shift in the fixing position of the thermosetting anisotropic conductive film 2 fixed on the first circuit member 1 by the temporary pasting step, the thermosetting anisotropic conductive film 2 The second circuit member 3 is disposed so that the terminals 3A of the second circuit member 3 are in contact with the thermosetting anisotropic conductive film 2 (FIG. 2D).

[Heat pressing process]
Next, the second circuit member 3 is heated and pressed by the heating pressing member (FIG. 2E).

  When there is no deviation in the fixed position, the joined body can be obtained by the above method. When there is a deviation in the fixed position, a repair process is performed.

[Repair process]
If there is a shift in the fixing position of the thermosetting anisotropic conductive film 2 fixed on the first circuit member 1 by the temporary sticking step, the adhesive tape 11 is attached to the thermosetting anisotropic conductive film 2. Is pasted (FIG. 2F).
Next, UV irradiation is performed to the thermosetting anisotropic conductive film 2 through the adhesive tape 11, and the thermosetting anisotropic conductive film 2 is photocured (FIG. 2G).
Next, the adhesive tape 11 is peeled from the first circuit member 1 together with the thermosetting anisotropic conductive film 2 (FIG. 2H).
By doing so, the 1st circuit member 1 which the thermosetting anisotropic film 2 has not adhered is reproduced | regenerated (FIG. 2I). The first circuit member 1 is reused in the temporary pasting process.

(Repair method)
In the repair method of the present invention, after sticking an adhesive tape to the thermosetting anisotropic conductive film fixed on the first circuit member by the temporary sticking step, the thermosetting anisotropy is passed through the adhesive tape. In this method, the conductive film is irradiated with light, the thermosetting anisotropic conductive film is photocured, and the adhesive tape is peeled off from the first circuit member together with the thermosetting anisotropic conductive film. . By this method, a reusable first circuit member is obtained.

  In the temporary pasting step, the thermosetting anisotropic conductive film is disposed on a terminal of the first circuit member, and the thermosetting anisotropic conductive film is pressed while pressing the thermosetting anisotropic conductive film. It is a step of fixing the thermosetting anisotropic conductive film on the first circuit member by heating at a temperature at which the film is not thermoset.

  The details of the repair method are the same as those of the repair step in the connection method, and the examples and preferred embodiments are also the same.

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

(Production Example 1)
<Preparation of anisotropic conductive film>
The following formulations were mixed uniformly to prepare a mixture.
-Formulation-
Phenoxy resin (trade name: YP-50, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) 50 parts by mass Urethane acrylate (trade name: M-1600, manufactured by Toagosei Co., Ltd.) 25 parts by mass Polyfunctional acrylate (trade name: M-315, Toagosei Co., Ltd.) 25 parts by mass Thermosetting agent (trade name: Parroyl L, manufactured by NOF Corporation) 4 parts by mass Photocuring agent (trade name: IRG184, manufactured by BASF) Conductive particles (trade name: Micropearl AU) 3 parts by mass of Sekisui Chemical Co., Ltd., average particle size 4 μm) The obtained mixture was applied to a silicone-treated PET (polyethylene terephthalate) with a bar coater so that the average thickness after drying was 20 μm, and 70 ° C. It dried for 5 minutes and produced the anisotropic conductive film.

(Production Example 2)
In Production Example 1, an anisotropic conductive film was obtained in the same manner as in Production Example 1 except that the phenoxy resin was replaced with a polyester urethane resin (trade name: UR4410, manufactured by Toyobo Co., Ltd.).

(Production Example 3)
In Production Example 1, an anisotropic conductive film was obtained in the same manner as in Production Example 1 except that the photocuring agent was changed to Darocur 1173 (manufactured by BASF).

(Production Example 4)
In Production Example 1, an anisotropic conductive film was obtained in the same manner as Production Example 1 except that the amount of the photocuring agent was changed to 0.5 parts by mass.

(Production Example 5)
In Production Example 1, an anisotropic conductive film was obtained in the same manner as in Production Example 1 except that the blending amount of the photocuring agent was changed to 2 parts by mass.

(Comparative Production Example 1)
In Production Example 1, an anisotropic conductive film was obtained in the same manner as Production Example 1 except that no photocuring agent was added.

(Production Example 6)
<Manufacture of acrylic resin>
The following acrylic monomers were blended in the following molar ratio and polymerized to synthesize an acrylic resin for pressure-sensitive adhesive.
-Monomer-
BA: n-butyl acrylate 2EHA: 2-ethylhexyl acrylate MMA: methyl methacrylate AA: acrylic acid HEMA: hydroxyethyl methacrylate-molar ratio-
BA / 2EHA / MMA / AA / HEMA = 30/53/9 / 7.5 / 0.5

(Production Example 7)
<Manufacture of photocurable adhesive tape>
The following formulations were mixed uniformly to prepare a mixture.
-Formulation-
80 parts by mass of acrylic resin produced in Production Example 6 20 parts by mass of polyfunctional acrylate (trade name: M-450, manufactured by Toagosei Co., Ltd.) 2 parts by mass of curing agent (trade name: Coronate L, manufactured by Tosoh Corporation) (Product name: IRG184, manufactured by BASF) 0.5 parts by mass

  The obtained mixture was coated on a PET (polyethylene terephthalate) having an average thickness of 25 μm with a bar coater so that the average thickness after drying was 5 μm, and dried at 70 ° C. for 5 minutes to prepare a photocurable pressure-sensitive adhesive tape.

(Production Example 8)
<Manufacture of adhesive tape>
The following formulations were mixed uniformly to prepare a mixture.
-Formulation-
80 parts by mass of acrylic resin produced in Production Example 6 2 parts by mass of curing agent (trade name: Coronate L, manufactured by Tosoh Corporation)

  The obtained mixture was coated on a PET (polyethylene terephthalate) having an average thickness of 25 μm with a bar coater so that the average thickness after drying was 5 μm, and dried at 70 ° C. for 5 minutes to prepare an adhesive tape.

<Manufacture of joined body>
The joined body was manufactured by the following method.
As the second circuit member, COF for evaluation (chip on flex) (Dexerials Corporation evaluation base material, 50 μm P (pitch), Cu 8 μmt (thickness) -Sn plating, PI (polyimide) 38 μmt (thickness) -S'perflex group Material).
As the first circuit member, ITO coating glass (Dexerials Corporation evaluation base material, full surface ITO coating, glass thickness 0.7 mm) was used.
An anisotropic conductive film slit to a width of 1.5 mm was disposed on the first circuit member. When arranging, it was fixed by attaching at 80 ° C., 1 MPa, and 1 second. Subsequently, the second circuit member was disposed on the anisotropic conductive film so as not to protrude from the anisotropic conductive film. Subsequently, it was pressure-bonded with a heating tool (width 1.5 mm) at 170 ° C. and 4 MPa for 5 seconds through a buffer material (Teflon (registered trademark), thickness 0.15 mm) to obtain a joined body.
The conduction resistance of the obtained joined body was evaluated by the following method. The results are shown in Table 1.

<< Conduction resistance >>
For the joined body, the initial conduction resistance value (Ω) was measured by the following method.
Specifically, the resistance value was measured when a current of 1 mA was passed by a four-terminal method using a digital multimeter (product number: digital multimeter 7555, manufactured by Yokogawa Electric Corporation). The resistance value was measured for 30 channels, and the maximum resistance value was taken as the measured value. Evaluation was made according to the following evaluation criteria.
〔Evaluation criteria〕
○: Less than 5Ω ×: 5Ω or more

(Examples 1-6, Comparative Example 1)
The repair property was evaluated by the following method using the anisotropic conductive film and the adhesive tape produced in the above production example. The combinations of anisotropic conductive film and adhesive tape and the results are shown in Tables 3-1 and 3-2.

[Repairability]
Repairability was evaluated by the following method.
(Step 1) An anisotropic conductive film was temporarily attached to a glass substrate on which ITO was formed at 80 ° C., 1 MPa, and 1 second.
(Process 2) Next, the adhesive tape was affixed on the anisotropic conductive film.
(Step 3) Next, UV irradiation was performed for 3 seconds from the top of the adhesive tape under the following UV irradiation conditions.
<< UV irradiation conditions >>
UV irradiation machine: SP-9, manufactured by USHIO INC. UV intensity: 300 mW / cm ^{2 at} 365 nm
(Step 4) Next, the adhesive tape was peeled from the anisotropic conductive film.
And it was confirmed by visual observation whether there was a residue of an anisotropic conductive film on a glass substrate, and the following evaluation criteria evaluated.
〔Evaluation criteria〕
○: Residue is less than 10% Δ: Residue is 10% or more and less than 50% ×: Residue is 50% or more

(Comparative Example 2)
In Example 6, repairability was evaluated in the same manner as in Example 6 except that UV irradiation was not performed (Step 3 was not performed). The results are shown in Table 3-2.

(Comparative Example 3)
In Example 6, repair property evaluation was performed in the same manner as in Example 6 except that UV irradiation was performed before the adhesive tape was attached to the anisotropic conductive film (the order of Step 2 and Step 3 was changed). Went. The results are shown in Table 3-2.

As with the anisotropic conductive film of Comparative Production Example 1, there was no problem in the conduction resistance when the anisotropic conductive films of Production Examples 1 to 5 were joined. That is, even when a photocuring agent was added to the anisotropic conductive film, there was no effect on the performance when a joined body was obtained.
Further, in Examples 1 to 5 using the anisotropic conductive films of Production Examples 1 to 5 and the photocurable adhesive tape, the repairability is higher than that in Example 6 using the non-photocurable adhesive tape. Was better. This is thought to be due to the fact that both the anisotropic conductive film and the adhesive layer of the adhesive tape were photocured by light irradiation, resulting in greater adhesion at the interface between the anisotropic conductive film and the adhesive layer of the adhesive tape. It is done.

On the other hand, when the anisotropic conductive film was not cured by light, the repair strength was insufficient because the film strength of the anisotropic conductive film was weak (Comparative Example 1).
When UV irradiation was not performed in a repair process, since the film | membrane intensity | strength of an anisotropic conductive film was weak, repair property was inadequate (comparative example 2).
After UV irradiation in the repair process, even when an adhesive tape was attached to the anisotropic conductive film, the repairability was insufficient (Comparative Example 3). This is presumably because the anisotropic conductive film was not covered with the adhesive tape, so that the inhibition of curing by oxygen occurred, and the film strength of the anisotropic conductive film did not increase.

DESCRIPTION OF SYMBOLS 1 1st circuit member 1A terminal 2 Thermosetting anisotropic conductive film 3 2nd circuit member 3A terminal 11 Adhesive tape

Claims (11)

A connection method for anisotropic conductive connection between a terminal of a first circuit member and a terminal of a second circuit member,
A thermosetting anisotropic conductive film is disposed on a terminal of the first circuit member, and the thermosetting anisotropic conductive film is heated at a temperature at which the thermosetting anisotropic conductive film is not thermoset while pressing the thermosetting anisotropic conductive film. A temporary pasting step of heating and fixing the thermosetting anisotropic conductive film on the first circuit member;
When there is no shift in the fixing position of the thermosetting anisotropic conductive film fixed on the first circuit member by the temporary pasting step, the thermosetting anisotropic conductive film is An arrangement step of arranging a second circuit member so that a terminal of the second circuit member is in contact with the thermosetting anisotropic conductive film;
A heating and pressing step of heating and pressing the second circuit member with a heating and pressing member,
When there is a shift in the fixing position of the thermosetting anisotropic conductive film fixed on the first circuit member by the temporary pasting step, an adhesive tape is applied to the thermosetting anisotropic conductive film. Then, the thermosetting anisotropic conductive film is irradiated with light through the adhesive tape, the thermosetting anisotropic conductive film is photocured, and further from the first circuit member, A repair step of peeling the adhesive tape together with the thermosetting anisotropic conductive film,
A connection method characterized by that.   The connection method according to claim 1, wherein the thermosetting anisotropic conductive film contains a photocuring agent.   The connection method according to claim 1, wherein the adhesive layer of the adhesive tape is photocurable.   The connection method according to claim 1, wherein the thermosetting anisotropic conductive film is a radical curable anisotropic conductive film.   The connection method according to claim 1, wherein the adhesive layer of the adhesive tape is photoradical curable. After sticking the adhesive tape to the thermosetting anisotropic conductive film fixed on the first circuit member by the temporary sticking step, the thermosetting anisotropic conductive film is irradiated with light through the adhesive tape. The repair method of photocuring the thermosetting anisotropic conductive film and further peeling the adhesive tape together with the thermosetting anisotropic conductive film from the first circuit member,
The temporary pasting step includes disposing the thermosetting anisotropic conductive film on a terminal of the first circuit member, and pressing the thermosetting anisotropic conductive film while pressing the thermosetting anisotropic conductive film. Heating the film at a temperature at which the film is not thermally cured, and fixing the thermosetting anisotropic conductive film on the first circuit member.
A repair method characterized by that.   The repair method of Claim 6 performed when the shift | offset | difference has arisen in the fixing position of the said thermosetting anisotropic conductive film fixed on the said 1st circuit member by the said temporary sticking process.   The repair method according to claim 6, wherein the thermosetting anisotropic conductive film contains a photocuring agent.   The repair method according to claim 6, wherein the adhesive layer of the adhesive tape is photocurable.   The repair method according to claim 6, wherein the thermosetting anisotropic conductive film is a radical curable anisotropic conductive film.   The repair method according to claim 6, wherein the adhesive layer of the adhesive tape is photoradical curable.