JP2016174126A - Connection method, and assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection method which allows for sufficient temporary fixing, even at the temperature of human skin, without requiring any special facility and process for temporary fixing.SOLUTION: A connection method performing anisotropic conductive connection of the terminal of a first circuit member 1 and the terminal of a second circuit member 3 includes a first arrangement step of arranging an anisotropic conductive film 2 on the terminal of the first circuit member 1, a second arrangement step of arranging the second circuit member 3 on the anisotropic conductive film 2, so that the terminal of the second circuit member 3 comes into contact with the anisotropic conductive film 2, a temporary fixing step of pressing the second circuit member 3 at the temperature of human skin, and a hot press step of hot pressing the second circuit member 3 by the hot pressing member 3. The anisotropic conductive film 2 contains liquid epoxy resin having a viscosity of 15-150 mPa s.SELECTED DRAWING: Figure 1

Description

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

  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.

As described above, when the circuit members are anisotropically conductively connected using the anisotropic conductive film, the following method is usually employed. After placing the anisotropic conductive film on the terminal of one circuit member, the other circuit member is placed at an appropriate position and temporarily fixed. Then, the main pressure bonding is performed by heating and pressing the other circuit member.
If temporary fixing is not performed, the arrangement of the one circuit member and the other circuit member may be misaligned before or during the main pressure bonding, and appropriate anisotropic conductive connection may not be performed. In addition, if temporary fixing is not performed, the other circuit member may be detached from the one circuit member before or during the main pressure bonding. As a result, production efficiency and yield are reduced.

  Therefore, a technique for temporarily fixing one circuit member and the other circuit member with a thermoplastic adhesive has been proposed in order to ensure temporary fixing (see, for example, Patent Document 1).

JP 2011-199138 A

  Usually, temporary fixing is performed using a heating and pressing member heated to a predetermined temperature. However, the temporarily fixed heating condition is not the same heating condition as the main pressure bonding, but is performed at a lower heating temperature than the main pressure bonding. For this reason, the heat pressing member for the main pressure bonding cannot be used in the temporary fixing, and a heat pressing member different from the main pressure bonding is required.

  Moreover, in the technique of the above-mentioned patent document 1, although it does not require heating at the time of temporary fixing, since the thermoplastic adhesive which does not contribute to anisotropic conductive connection is used, the material to be used increases and the thermoplastic adhesive is used. In order to apply the agent, the number of processes is increased, and further, equipment for applying the thermoplastic adhesive is required.

  Although productivity can be improved if equipment or processes for connecting anisotropically conductive circuit members to each other using an anisotropic conductive film can be reduced, reduction of equipment or processes focusing on temporary fixation The current situation is that this reduction has not been achieved.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention provides a connection method and a joined body capable of performing sufficient temporary fixing even if temporary fixing is performed at the temperature of human skin without requiring special equipment and processes for temporary fixing. The purpose is to provide.

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 first disposing step of disposing an anisotropic conductive film on the terminal of the first circuit member;
A second disposing step of disposing the second circuit member on the anisotropic conductive film such that a terminal of the second circuit member is in contact with the anisotropic conductive film;
A temporary fixing step of pressing the second circuit member at a human skin temperature;
A heating and pressing step of heating and pressing the second circuit member with a heating and pressing member;
Including
The anisotropic conductive film contains a liquid epoxy resin having a viscosity of 15 mPa · s to 150 mPa · s.
It is the connection method characterized by this.
<2> The connection method according to <1>, wherein the liquid epoxy resin having a viscosity of 15 mPa · s to 150 mPa · s is a dicyclopentadiene type epoxy resin.
<3> The connection method according to <2>, wherein the dicyclopentadiene-type epoxy resin is dicyclopentadiene dimethanol diglycidyl ether.
<4> A joined body obtained by the connection method according to any one of <1> to <3>.

  According to the present invention, the conventional problems can be solved and the object can be achieved, and temporary fixing is performed at the temperature of human skin without requiring special equipment and processes for temporary fixing. However, it is possible to provide a connection method and a joined body that can perform sufficient temporary fixing.

FIG. 1 is an explanatory diagram showing a method for measuring a temporary fixing force and a peel strength in Examples.

(Connection method and joined body)
The connection method of the present invention includes at least a first arrangement step, a second arrangement step, a temporary fixing step, and a heating and pressing step, and further includes other steps 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.

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

  The present inventors pay attention to temporary fixing between the first circuit member and the second circuit member when the circuit members are anisotropically conductively connected to each other using an anisotropic conductive film. We examined whether productivity could be improved by reducing the number of processes. And, by performing the temporary fixing at the temperature of the human skin, an attempt was made to perform temporary fixing without requiring heating equipment. In that case, temporary fixing becomes insufficient (the peel strength due to temporary fixing is insufficient). I found out). Therefore, as a result of further investigation, by including a liquid epoxy resin having a viscosity of 15 mPa · s to 150 mPa · s in the anisotropic conductive film used for the anisotropic conductive connection, temporary fixing at the temperature of human skin. The inventors have found a connection method capable of obtaining sufficient peel strength and completed the present invention.

  In the temporary fixing, the anisotropic conductive film is heated and cured by heating and pressure, and the conductive particles in the anisotropic conductive film are crushed and anisotropic conductive connection is performed (in the present invention, heating is performed) Different from the pressing step). The temporary fixing is performed before the main press bonding, and is performed in order to prevent misalignment between the first circuit member and the second circuit member in manufacturing (connecting method) of the joined body.

<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 board | 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.

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

<< anisotropic conductive film >>
The anisotropic conductive film contains at least a liquid epoxy resin having a viscosity of 15 mPa · s to 150 mPa · s, and preferably contains a film-forming resin, another epoxy resin, a curing agent, and conductive particles. Further, it contains other components as required.
Even if the viscosity of the liquid epoxy resin is less than 15 mPa · s or more than 150 mPa · s, the temporary fixing force is insufficient.

-Liquid epoxy resin-
The liquid epoxy resin is not particularly limited as long as it is a liquid epoxy resin having a viscosity of 15 mPa · s to 150 mPa · s, and can be appropriately selected according to the purpose, but is a dicyclopentadiene type epoxy resin. Is preferred, and dicyclopentadiene dimethanol diglycidyl ether is more preferred.
The dicyclopentadiene skeleton has rigidity and large steric hindrance. As a result, even if the crosslinking density is small, a high Tg can be expressed.

  The liquid epoxy resin preferably has two or more epoxy groups, and more preferably has two epoxy groups. In the liquid epoxy resin, when there is one epoxy group, since the volatility is high, stable anisotropic conductive connection may not be performed.

  The dicyclopentadiene type epoxy resin may be a commercially available product. As said commercial item, EP4088S (made by ADEKA company, dicyclopentadiene dimethanol diglycidyl ether) etc. are mentioned, for example.

In the present invention, the viscosity of the liquid epoxy resin is measured under the following conditions.
A glass container (opening size: φ34 mm, bottom diameter: φ45 mm, height: 80 mm) containing about 70 g of liquid epoxy resin is immersed in a constant temperature water bath (Uniace, model: UA-1100, manufactured by Tokyo Rika Kikai Co., Ltd.) at 35 ° C. And the viscosity is measured using a viscometer (model: TVB-10H, manufactured by Toki Sangyo Co., Ltd.). In addition, the rotor type at the time of viscosity measurement is No. 5 and the rotation speed is 50 rpm.

  The content of the liquid epoxy resin having a viscosity of 15 mPa · s to 150 mPa · s in the anisotropic conductive film is not particularly limited and may be appropriately selected depending on the intended purpose. 20.0 mass% is preferable, 3.0 mass%-15.0 mass% is more preferable, 3.0 mass%-11.0 mass% is especially preferable. When the content is within a particularly preferable range, it is advantageous in that the peel strength in the obtained bonded body is more excellent.

-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 anisotropic conductive film, Although it can select suitably according to the objective, 5 mass%-40 mass% are preferable, and 10 mass%-30 mass. % Is more preferable, and 15% by mass to 25% by mass is particularly preferable.

-Other epoxy resins-
There is no restriction | limiting in particular as said other epoxy resin, According to the objective, it can select suitably, For example, naphthalene type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin, those Examples thereof include modified epoxy resins and alicyclic epoxy resins. These may be used individually by 1 type and may use 2 or more types together.
Among these, naphthalene type epoxy resins are preferable in that they can be connected in a short time because they have fast curing properties.

  There is no restriction | limiting in particular as content of the said other epoxy resin in the said anisotropic conductive film, Although it can select suitably according to the objective, 10 mass%-40 mass% are preferable, and 20 mass%-30 The mass% is more preferable.

-Curing agent-
The curing agent is not particularly limited as long as it is a curing agent that cures an epoxy resin, and can be appropriately selected according to the purpose. Examples thereof include imidazoles, anionic curing agents, and cationic curing agents. It is done.

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 film, Although it can select suitably according to the objective, 20 mass%-50 mass% are preferable, and 30 mass%-40 mass% are preferable. 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 anisotropic conductive film, Although it can select suitably according to the objective, 0.5 mass%-10 mass% are preferable, and 1 mass%- 3 mass% is more preferable.

-Other ingredients-
As said other component, an elastomer etc. are mentioned, for example.

--Elastomer--
There is no restriction | limiting in particular as said elastomer, According to the objective, it can select suitably, For example, a polyurethane resin (polyurethane-type elastomer), an acrylic rubber, a silicone rubber, a butadiene rubber etc. are mentioned.

  There is no restriction | limiting in particular as content of the said elastomer in the said anisotropic conductive film, Although it can select suitably according to the objective, 1 mass%-15 mass% are preferable, and 3 mass%-10 mass% are preferable. More preferred.

  There is no restriction | limiting in particular as average thickness of the said anisotropic conductive film, Although it can select suitably according to the objective, 2 micrometers-60 micrometers are preferable, 5 micrometers-45 micrometers are more preferable, and 15 micrometers-35 micrometers are especially preferable.

<Second arrangement step>
As said 2nd arrangement | positioning process, if it is the process of arrange | positioning the said 2nd circuit member on the said anisotropic conductive film so that the terminal of the said 2nd circuit member may contact | connect the said anisotropic conductive film There is no particular limitation, and it can be appropriately selected according to the purpose.

<Temporary fixing process>
The temporary fixing step is not particularly limited as long as it is a step of pressing the second circuit member at the temperature of human skin, and can be appropriately selected according to the purpose.
The temperature of the human skin is, for example, 35 ° C to 37 ° C.

  In the temporary fixing step, the second circuit member may be pressed using a pressing member having a human skin temperature. A person may press the second circuit member with a finger.

  The pressing member is not particularly limited as long as it can press the second circuit member, and can be appropriately selected according to the purpose.

There is no restriction | limiting in particular as a pressure of the pressure in the said temporary fixing process, According to the objective, it can select suitably.
There is no restriction | limiting in particular as time of the press in the said temporary fixing process, According to the objective, it can select suitably.

  In the temporary fixing step, the anisotropic conductive film contains the liquid epoxy resin having a viscosity of 15 mPa · s to 150 mPa · s, so that the first circuit member Sufficient temporary fixing force (peeling strength) can be obtained in order to prevent displacement from the second circuit member.

<Heat pressing process>
The heating and pressing step is not particularly limited as long as it is a step of heating and pressing the second circuit member with a heating and pressing member, and can be appropriately selected according to the purpose. And can be pressed.
Examples of the heating and pressing member include a pressing member having a heating mechanism. Examples of the pressing member having the heating mechanism include a heat tool.
There is no restriction | limiting in particular as 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-8 MPa are preferable.
There is no restriction | limiting in particular as time of the said heating and a press, According to the objective, it can select suitably, For example, 1 second-120 second etc. are mentioned.

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

Example 1
<Preparation of anisotropic conductive film>
The following formulations were mixed uniformly to prepare a mixture.
-Formulation-
Phenoxy resin (Product name: YP50, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) 30 parts by mass Naphthalene type epoxy resin (Product name: HP4032D, manufactured by DIC) 35 parts by mass Dicyclopentadiene type epoxy resin (Product name: EP4088S, manufactured by ADEKA) 10 parts by mass Elastomer (Product name: Teisan Resin SG-80H, manufactured by Nagase Chemtech) 10 parts by weight Curing agent (Product name: Novacure 3941HP, manufactured by Asahi Kasei E-Materials Co., Ltd.) 55 parts by weight Conductive particles (Product name: Bright, manufactured by Nippon Chemical Industry Co., Ltd.) 3 parts by mass of an average particle diameter of 10 μm) The obtained mixture was coated on a silicone-treated PET (polyethylene terephthalate) with a bar coater so that the average thickness after drying was 35 μm, and dried at 70 ° C. for 5 minutes. An isotropic conductive film (ACF) was produced.

<Manufacture of joined body>
The joined body was manufactured by the following method.
As the second circuit member, a flexible substrate (base material for evaluation by Dexerials Corporation, 0.2 mm pitch (line / space = 0.1 mm / 0.1 mm), Cu 12 μmt (thickness) -nickel / gold plating process, PI (polyimide) ) 25 μmt (thickness)) was used.
As a first circuit member, a printed wiring board (Dexerials Corporation evaluation board, 0.2 mm pitch (line / space = 0.1 mm / 0.1 mm), Cu 35 μmt (thickness) -nickel / gold plating treatment, substrate thickness 1.0 mm) was used.
The anisotropic conductive film slit to a width of 2.0 mm was disposed on the first circuit member. Subsequently, the second circuit member was temporarily fixed on the anisotropic conductive film. The temporary fixing was performed by pressing the second circuit member for 2 seconds using a pressing member. The temperature at the time of temporary fixing was set so that the anisotropic conductive film had a temperature comparable to human skin (35 ° C.). Subsequently, the second circuit member is heated and pressed (main press bonding) at 190 ° C., 2 MPa for 10 seconds with a heating tool (width 2.0 mm) through a buffer material (silicon rubber, thickness 0.2 mm). )did. Thus, a joined body was obtained.

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

<< Temporary fixing force >>
The temporary fixing force between the first circuit member and the second circuit member after the temporary fixing was finished and before the main press bonding was measured. Specifically, using a peel tester (manufactured by A & D Co., Ltd.), a 90 degree peel test (JIS K6854-1) was performed as shown in FIG. 1 at a peel speed of 50 mm / min. The peel strength was determined and used as the temporary fixing force. The measurement results were evaluated according to the following evaluation criteria. The results are shown in Table 1. In FIG. 1, reference numeral 1 indicates a first circuit member, reference numeral 2 indicates an anisotropic conductive film, and reference numeral 3 indicates a second circuit member. The second circuit member is pulled in the direction of the arrow by a peel tester.
〔Evaluation criteria〕
○: 1.5 N / cm or more Δ: 0.5 N / cm or more and less than 1.5 N / cm ×: less than 0.5 N / cm When the peel strength is less than 1.5 N / cm, the temporarily fixed product is moved In addition, there is a high possibility that the first circuit member and the second circuit member may be detached when the operator handles them roughly.

<< Peel strength >>
As shown in FIG. 1, the manufactured joined body was subjected to a 90 degree peel test (JIS K6854-1) using a peel tester (manufactured by A & D Co., Ltd.) at a peel speed of 50 mm / min. The peel strength was measured as the adhesive strength. The measurement results were evaluated according to the following evaluation criteria. The results are shown in Table 1.
〔Evaluation criteria〕
○: 10 N / cm or more Δ: 4 N / cm or more and less than 10 N / cm ×: less than 4 N / cm

<< Comprehensive judgment >>
Comprehensive judgment was performed according to the following evaluation criteria. The results are shown in Table 1.
〔Evaluation criteria〕
○: Both temporary fixing force and peel strength are “○”
Δ: The temporary fixing force is “◯” and the peel strength is “Δ”.
×: The temporary fixing force is “Δ” or “×”, or the temporary fixing force is “◯”, but the peel strength is “×”.

(Examples 1-4, Comparative Examples 1 and 2)
<Preparation of anisotropic conductive film>
In Example 1, the anisotropic conductive film was obtained like Example 1 except having changed the composition into the composition shown in Table 1. Furthermore, a joined body was obtained.

  Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

Phenoxy resin: Product name: YP-50, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. 1: Naphthalene type epoxy resin, HP4032D, manufactured by DIC, viscosity: 4,500 mPa · s
Epoxy resin no. 2: Dicyclopentadiene type epoxy resin, EP4088S, manufactured by ADEKA, viscosity: 140 mPa · s
Epoxy resin no. 3: Bisphenol A type epoxy resin, YL980, manufactured by Mitsubishi Chemical Corporation, viscosity: 3,700 mPa · s
Epoxy resin no. 4: Bisphenol F type epoxy resin, YL983U, manufactured by Mitsubishi Chemical Corporation, viscosity: 1,240 mPa · s
Elastomer: Teisan Resin SG-80H, manufactured by Nagase ChemteX Corp. Curing agent: Novacure 3941HP, manufactured by Asahi Kasei E-Materials Co., Ltd. Conductive particles: Bright, manufactured by Nippon Chemical Industry Co., Ltd., average particle size 10 μm

In Examples 1 to 4, since the anisotropic conductive film contains a liquid epoxy resin having a viscosity of 15 mPa · s to 150 mPa · s, sufficient temporary fixing force can be obtained even if temporary fixing is performed at the temperature of human skin. was gotten. In Examples 1 to 3, the peel strength was excellent.
In Comparative Examples 1 and 2, the anisotropic conductive film contains a liquid epoxy resin, but its viscosity is not 15 mPa · s to 150 mPa · s, and thus when temporarily fixed at the temperature of human skin. A sufficient temporary fixing force could not be obtained.
In addition, when an anisotropic conductive film does not contain a liquid epoxy resin, it becomes a result similar to the comparative example 1.

DESCRIPTION OF SYMBOLS 1 1st circuit member 2 Anisotropic conductive film 3 2nd circuit member

Claims (4)

A connection method for anisotropic conductive connection between a terminal of a first circuit member and a terminal of a second circuit member,
A first disposing step of disposing an anisotropic conductive film on the terminal of the first circuit member;
A second disposing step of disposing the second circuit member on the anisotropic conductive film such that a terminal of the second circuit member is in contact with the anisotropic conductive film;
A temporary fixing step of pressing the second circuit member at a human skin temperature;
A heating and pressing step of heating and pressing the second circuit member with a heating and pressing member;
Including
The anisotropic conductive film contains a liquid epoxy resin having a viscosity of 15 mPa · s to 150 mPa · s.
A connection method characterized by that.   The connection method according to claim 1, wherein the liquid epoxy resin having a viscosity of 15 mPa · s to 150 mPa · s is a dicyclopentadiene type epoxy resin.   The connection method according to claim 2, wherein the dicyclopentadiene type epoxy resin is dicyclopentadiene dimethanol diglycidyl ether.   A joined body obtained by the connection method according to claim 1.