KR20230114290A - Manufacturing method of connected body and connected body - Google Patents

Abstract

A manufacturing method of a connected body having excellent manufacturing efficiency is provided. A manufacturing method of a connected body having the following steps 1 to 2. Step 1: A step of forming a conductive adhesive layer by applying an adhesive and a coating liquid for a conductive adhesive layer containing conductive particles having a conductive layer on the surface of a resin core on a first metal substrate and drying the coating liquid. In Step 1, when the average thickness of the conductive adhesive layer is defined as T1 [μm] and the average particle diameter of the conductive particles is defined as D1 [μm], the relationship of T1 < D1 is satisfied. Process 2: The process of laminating a 2nd metal substrate on the said conductive adhesive layer, and obtaining the connection body which has the said 1st metal substrate, the said conductive adhesive layer, and the said 2nd metal substrate in this order.

Description

Manufacturing method of connected body and connected body

The present invention relates to a method for manufacturing a connected body and a connected body.

As a material for electrical and electronic devices and the like, a connector electrically connecting two metal substrates via an adhesive layer may be used.

An isotropic conductive adhesive and an anisotropic conductive adhesive are mentioned as the adhesive used for a connection body.

Representative examples of isotropically conductive adhesives include adhesives using carbon black as a conductive agent. An isotropically conductive adhesive needs to contain a large amount of a conductive agent in the adhesive for electrical connection. For this reason, the connection body using an isotropically conductive adhesive has a problem that interlayer adhesiveness tends to fall. In addition, a connection body using an isotropically conductive adhesive has a problem that the resistance value cannot be sufficiently lowered.

As a representative example of a connection body using an anisotropically conductive adhesive, a connection body using an anisotropically conductive film (ACF) is exemplified. ACF is an adhesive film in which conductive particles such as metal particles and metal plating resin particles are uniformly dispersed.

ACF is a connecting material that electrically connects the pressing direction between circuit boards by heating and pressurizing after being disposed between circuit boards, while ensuring insulation in a direction perpendicular to the pressing direction.

As a connection body using ACF, for example, Patent Literatures 1 and 2 are proposed.

Japanese Unexamined Patent Publication No. 2016-1562 Japanese Unexamined Patent Publication No. 2019-179647

The connection body using ACF, such as patent document 1 and 2, electrically connects the pressing direction. For this reason, since a connection body using ACF does not need to contain a large amount of conductive particles in the adhesive, an improvement in interlayer adhesion can be expected.

However, since the connection body using ACF requires an alignment process for aligning the positions of the upper surface plate and the lower surface plate and a heat-pressing process after the alignment process, it cannot be continuously manufactured, and the production efficiency is poor.

This invention makes it a subject to provide the manufacturing method of the connected body excellent in manufacturing efficiency. Moreover, the present invention makes it a subject to provide a connection body capable of electrically connecting two metal substrates with a simple configuration.

In order to solve the above problems, the present invention provides the following [1] to [17].

[1] A method for manufacturing a connected body comprising steps 1 to 2 below.

Step 1: A step of forming a conductive adhesive layer by applying an adhesive and a coating liquid for a conductive adhesive layer containing conductive particles having a conductive layer on the surface of a resin core on a first metal substrate and drying the coating liquid. In Step 1, when the average thickness of the conductive adhesive layer is defined as T1 [μm] and the average particle diameter of the conductive particles is defined as D1 [μm], the relationship of T1 < D1 is satisfied.

Process 2: The process of laminating a 2nd metal base material on the said conductive adhesive layer, and obtaining the connection body which has the said 1st metal base material, the said conductive adhesive layer, and the said 2nd metal base material in this order.

[2] The method for producing a connected body according to [1], wherein the resin core has a compression recovery rate of 5% or more and 55% or less.

[3] The method for producing a connected body according to [1] or [2], wherein the conductive particles are contained in an amount of 0.1 part by mass or more and 2.0 parts by mass or less with respect to 100 parts by mass of the adhesive.

[4] In Step 1, the method for producing a connected body according to any one of [1] to [3], wherein the adhesive contains a base material and a curing agent, and the glass transition temperature of the base material is -5°C or higher.

[5] The method for producing a connected body according to any one of [1] to [4], wherein the adhesive contains a main agent and a curing agent, and the lamination temperature in step 2 is equal to or higher than the glass transition temperature of the main subject.

[6] The method for manufacturing a connected body according to any one of [1] to [5], which further includes step 3 below.

Step 3: A step of aging the connected body.

[7] The method for producing a connected body according to [6], wherein in step 3, the temperature of the aging treatment is set to 55°C or less.

[8] The method for producing a connected body according to [6] or [7], wherein the glass transition temperature of the adhesive after step 3 is -1°C or higher.

[9] When the average thickness of the conductive adhesive layer after step 3 is defined as Tn [μm] and the average diameter of the conductive particles in the thickness direction is defined as Dn [μm], the relationship of Tn ≤ Dn is satisfied, [6] to The method for manufacturing a connected body according to any one of [8].

[10] By continuously sending out the first metal substrate from the roll-like product of the first metal substrate, the above step 1 is performed, and by continuously feeding the second metal substrate from the roll-like product of the second metal substrate. , The method for manufacturing a connected body according to any one of [1] to [9], in which step 2 is performed.

[11] a first metal substrate, a conductive adhesive layer, and a second metal substrate in this order, the conductive adhesive layer including an adhesive and conductive particles having a conductive layer on the surface of a resin core, the conductive adhesive layer A connection body in which Dn/Tn satisfies a relationship of greater than 1.00 when the average thickness of is defined as Tn [μm] and the average of the diameters in the thickness direction of the conductive particles is defined as Dn [μm].

[12] The connected body according to [11], wherein Dn/Tn satisfies the relationship of 1.01 or more and 1.50 or less.

[13] The area of the connected body when viewed from a plane is S, the area of the first metal substrate when the connected body is viewed from a plane is S1, and the area of the second metal substrate when the connected body is viewed from a plane is The connected body according to [11] or [12], which satisfies the following formulas (1) and (2) when set to S2.

0.99≤S1/S≤1.01 (1)

0.99≤S2/S≤1.01 (2)

[14] S1 is the area of the first metal substrate when the connecting body is viewed from a plane, S2 is the area of the second metal substrate when the connecting body is viewed from a plane, and the area of the conductive adhesive layer when the connecting body is viewed from a plane The connected body according to any one of [11] to [13], which satisfies the following formulas (3) and (4) when is set to S3.

1.00≤S1/S3≤1.02 (3)

1.00≤S2/S3≤1.02 (4)

[15] The connected body according to any one of [11] to [14], wherein the resin core has a compression recovery rate of 5% or more and 55% or less.

[16] The connection body according to any of [11] to [15], wherein the conductive particles are contained in an amount of 0.1 part by mass or more and 2.0 parts by mass or less with respect to 100 parts by mass of the adhesive.

[17] The connected body according to any one of [11] to [16], wherein the adhesive has a glass transition temperature of -1°C or higher.

The manufacturing method of the connected body of this invention can manufacture connected bodies continuously and can improve manufacturing efficiency. Further, the connection body of the present invention can electrically connect two metal substrates with a simple configuration.

1 is a cross-sectional view showing one embodiment of a state after step 1 in the manufacturing method of a connected body of the present invention.
Fig. 2 is a cross-sectional view showing an embodiment of a state after Step 2 in the manufacturing method of a connected body of the present invention.
3 is a schematic diagram showing one embodiment of a manufacturing method in roll-to-roll, which is one embodiment of the manufacturing method of the connected body of the present invention.

Hereinafter, an embodiment of a method for manufacturing a connected body of the present invention and an embodiment of a connected body of the present invention will be described.

[Method of manufacturing connection body]

The manufacturing method of the connected body of this invention has the following steps 1-2.

Step 1: A step of forming a conductive adhesive layer by applying an adhesive and a coating liquid for a conductive adhesive layer containing conductive particles having a conductive layer on the surface of a resin core on a first metal substrate and drying the coating liquid. In Step 1, when the average thickness of the conductive adhesive layer is defined as T1 [μm] and the average particle diameter of the conductive particles is defined as D1 [μm], the relationship of T1 < D1 is satisfied.

Process 2: The process of laminating a 2nd metal substrate on the said conductive adhesive layer, and obtaining the connection body which has the said 1st metal substrate, the said conductive adhesive layer, and the said 2nd metal substrate in this order.

<Process 1>

Step 1 is a step of forming a conductive adhesive layer by applying and drying a coating liquid for a conductive adhesive layer containing an adhesive and conductive particles having a conductive layer on the surface of a resin core on a first metal substrate. In Step 1, when the average thickness of the conductive adhesive layer is defined as T1 [μm] and the average particle diameter of the conductive particles is defined as D1 [μm], it is required to satisfy the relationship of T1 < D1.

1 is a cross-sectional view showing an embodiment of a state after Step 1.

The laminate 50 in FIG. 1 has a conductive adhesive layer 30 on the first metal substrate 10 . In FIG. 1 , the conductive adhesive layer 30 has an adhesive 31 and conductive particles 32 having a conductive layer on the surface of a resin core.

In step 1, it is required to satisfy the relationship of T1<D1.

By satisfying the relationship of T1<D1, the first metal substrate and the second metal substrate are electrically electrically bonded by a simple lamination process without processing at high temperature and high pressure during manufacture, as in conventional ACF-using connectors. can connect

The ratio of D1 to T1 (D1/T1) is preferably 1.03 or more, more preferably 1.05 or more, and still more preferably 1.10 or more. By making the said ratio into 1.03 or more, it can make it easy to electrically connect a 1st metal substrate and a 2nd metal substrate.

The ratio of D1 to T1 (D1/T1) is preferably 1.50 or less, more preferably 1.30 or less, and still more preferably 1.20 or less. By making the said ratio into 1.50 or less, the interlayer adhesiveness of a connection body can be easily made good.

The difference between D1 and T1 (D1-T1) is preferably 0.1 μm or more, more preferably 0.3 μm or more, and still more preferably 0.4 μm or more. By making the said difference into 0.1 micrometer or more, it can make it easy to electrically connect a 1st metal substrate and a 2nd metal substrate.

The difference between D1 and T1 (D1-T1) is preferably 2.0 μm or less, more preferably 1.0 μm or less, and still more preferably 0.7 μm or less. By making the said difference into 2.0 micrometers or less, the interlayer adhesiveness of a connection body can easily be made good.

The ranges of T1 and D1 are not particularly limited as long as the relationship of T1 < D1 is satisfied, but are preferably within the following ranges.

T1 representing the average thickness of the conductive adhesive layer is preferably 1.0 μm or more and 10.0 μm or less, more preferably 2.0 μm or more and 8.0 μm or less, and still more preferably 3.0 μm or more and 6.0 μm or less. By setting T1 to 1.0 μm or more, the interlayer adhesion of the connection body can be easily improved, and contact between the first metal substrate and the second metal substrate without passing through the conductive particles can be easily suppressed. By setting T1 to 10.0 μm or less, the coating stability of the conductive adhesive layer can be easily improved.

D1 representing the average particle diameter of the conductive particles is preferably 1.5 μm or more and 12.0 μm or less, more preferably 2.5 μm or more and 9.0 μm or less, and still more preferably 3.5 μm or more and 7.0 μm or less.

In this specification, T1 representing the average thickness of the conductive adhesive layer is the average value of the thickness of the conductive adhesive layer at 30 randomly selected locations. The measurement of the thickness of the above-mentioned 30 places shall be performed after the process 1 is completed and before the start of the process 2. The thickness of the above-mentioned 30 locations can be measured from a cross-sectional photograph of the conductive adhesive layer taken with, for example, an SEM or the like.

In this specification, D1 which shows the average particle diameter of electroconductive particle can be measured, for example in the procedure of following A1 and A2. The following A1 and A2 shall be performed after process 1 is completed and before the start of process 2.

A1: A cross-sectional photograph of the conductive adhesive layer is taken with a SEM or the like.

A2: Measure the maximum diameter of the conductive particles in the cross-sectional photograph. Let the maximum diameter average of 30 electroconductive particles in total be D1.

<< metal substrate >>

Examples of the metal constituting the first metal substrate used in Step 1 and the second metal substrate used in Step 2 include one or two or more selected from copper, stainless steel, brass, silver, aluminum, and nickel.

The metal constituting the first metal substrate and the second metal substrate may be of the same type or may be of different types.

The first metal substrate and the second metal substrate may be subjected to a process of roughening the surface of the substrate or removing residual oil from the surface of the substrate in order to improve adhesion.

The thickness of the first metal substrate and the second metal substrate is preferably 1 μm or more and 200 μm or less, more preferably 3 μm or more and 100 μm or less, and still more preferably 6 μm or more and 50 μm or less.

By setting the thickness to 1 μm or more, predetermined strength can be imparted to the first metal substrate and the second metal substrate, and breakage of the substrate when tension is applied to the substrate can be easily suppressed.

Since it becomes easy to wind up a 1st metal base material and a 2nd metal base material by making thickness into 200 micrometers or less, a connection body can be easily manufactured by roll-to-roll.

Although the 1st metal substrate and the 2nd metal substrate may be sheet|leaf shape, it is preferable that they are roll shape. By forming the first metal substrate and the second metal substrate into a roll shape, production by roll-to-roll described later becomes possible, and production efficiency can be dramatically increased.

<<Conductive adhesive layer>>

In Step 1, the conductive adhesive layer is formed by applying an adhesive and a coating liquid for a conductive adhesive layer containing conductive particles having a conductive layer on the surface of a resin core and drying.

It is preferable that the coating liquid for conductive adhesive layers contains a solvent. As the solvent, ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), Esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (isopropanol, butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), glycol ethers (propylene glycol mono) organic solvents such as methyl ether acetate), and the like. Moreover, as a solvent, the mixed solvent of the said organic solvent and water can also be used. The solvent may be one type of solvent or a mixed solvent of two or more types.

As the application means, general-purpose application means such as gravure coating, bar coating, roll coating, reverse roll coating, comma coating, and die coating are exemplified.

What is necessary is just to adjust drying conditions with the characteristics of a metal substrate, the material which comprises the coating liquid for conductive adhesive layers, the coating amount of a coating liquid, etc. For example, it is preferable to set the drying temperature to 80°C or more and 120°C or less, and the drying time to be 30 seconds or more and 90 seconds or less. Within the above temperature range, expansion and the like of the metal substrate can be easily suppressed, and the quality of the connection body can be easily improved.

-glue-

Examples of the adhesive include adhesives such as urethane-based adhesives, acrylic adhesives, epoxy-based adhesives, polyester-based adhesives, olefin-based adhesives, and rubber-based adhesives. Among these adhesives, urethane-based adhesives and acrylic adhesives are preferred, and urethane-modified acrylic adhesives are more preferred. The adhesive is preferably a thermosetting adhesive.

The adhesive preferably contains a main agent and a curing agent in order to stabilize the resistance value over time.

As the main material of the adhesive, a general-purpose compound can be used. Specific examples of the main subject include acrylic resins; polyester-based resin; polyimide-based resin; polyol compounds such as polyether polyol, polyester polyol and acrylic polyol; compounds having an epoxy group such as an epoxy resin; Olefin type resin; etc. can be mentioned. The polyol compound may be modified. Examples of the modified polyol compound include urethane-modified acrylic polyol.

The main glass transition temperature of the adhesive is preferably -5°C or higher, more preferably 10°C or higher, still more preferably 20°C or higher, and still more preferably 30°C or higher. By setting the glass transition temperature of the main material to -5°C or higher, it is easier for the adhesive to suppress the restoration of the conductive particles to their original shape after step 2, so that the resistance value of the connecting body increases with time. can be suppressed The main glass transition temperature of the adhesive may be less than -5°C. Since the lamination temperature in step 2 can be lowered by setting the glass transition temperature of the main material to less than -5°C, workability can be easily improved.

The glass transition temperature of the main material of the adhesive is preferably 100°C or less, more preferably 80°C or less, and still more preferably 70°C or less. By setting the glass transition temperature of the main material to 100° C. or less, the adhesive is easily softened by heat during lamination in Step 2. For this reason, the contact area between the adhesive layer and the second metal substrate tends to increase, and adhesion can be easily improved. In addition, since the adhesive is easily softened by the heat during lamination in Step 2, the adhesive present above the conductive particles (the adhesive 31 present above the conductive particles 32 in Fig. 1) is affected by the pressure during lamination. It becomes easy to spread thinly, and the conductive particles and the second metal substrate can be easily brought into contact.

The glass transition temperature of the main material can be adjusted by general-purpose means such as weight average molecular weight.

As the curing agent for the adhesive, a general-purpose compound can be used. Specific examples of the curing agent include isocyanate compounds such as aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate, and aliphatic polyisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate. Further, as other specific examples of the curing agent, amine-based compounds, phenol-based compounds, active ester-based compounds, and the like can be cited.

When an isocyanate-based compound is used as the curing agent, the equivalent ratio of the isocyanate group of the isocyanate to the hydroxyl group of the main agent is preferably 0.1 or more and 2.0 or less, and more preferably 0.5 or more and 1.0 or less.

By making the said ratio into 0.1 or more, the glass transition temperature of the adhesive after completion of a connected body can be made easy to be -1 degreeC or more. By making the said ratio into 2.0 or less, expansion by the carbon dioxide generated by reaction with the water|moisture content unexpectedly contained at the time of lamination can be suppressed.

-Conductive Particles-

In the present invention, as conductive particles, particles having a conductive layer on the surface of a resin core are used. Since these conductive particles have a conductive layer on the surface, the first metal substrate and the second metal substrate can be electrically connected. In addition, since the core of these conductive particles is a resin, the particle size in the thickness direction is reduced by the pressure during lamination in Step 2. In addition, when the particle size of the conductive particles in the thickness direction decreases, the contact area between the conductive adhesive layer and the second metal substrate increases, and adhesion can be easily improved (see FIGS. 1 and 2).

Particles having a conductive layer on the surface of the resin core can be obtained, for example, by plating or depositing a metal on the resin core.

The conductive particles are preferably particles having protrusions on the surface. Oxide films may be formed on the surfaces of the first metal substrate and the second metal substrate. In such a case, since the oxide film is easily torn by the conductive particles having projections on the surface, it is possible to easily electrically connect the first metal substrate and the second metal substrate.

Particles having projections on the surface can be obtained, for example, by arranging a plurality of core substances that form projections on the surface of a resin core, and then plating or depositing metal.

As a method for adhering the core substance to the surface of the resin core particles, for example, a method in which the core substance is added to a resin core dispersion and accumulated on the surface of the resin core particles by van der Waals force or the like. can be heard

Examples of the resin constituting the resin core include benzoguanamine resin, acrylic resin, styrene resin, silicone resin, and polybutadiene resin. Moreover, as resin which comprises a resin core, the copolymer which combined 2 or more types of monomer which comprises the above-mentioned resin is also mentioned.

The resin core preferably has a compression recovery factor of 55% or less, more preferably 47% or less, more preferably 40% or less, more preferably 30% or less, and more preferably 18% or less. By setting the compression recovery rate to 55% or less, the particle diameter of the conductive particles in the thickness direction tends to be reduced due to the pressure at the time of lamination in step 2. For this reason, the contact area between the conductive adhesive layer and the second metal substrate increases, and the interlayer adhesion of the connected body can be easily improved.

The resin core preferably has a compression recovery rate of 5% or more, more preferably 6% or more, and still more preferably 7% or more. By setting the compression recovery factor to 5% or more, it can be suppressed that the particle diameter in the thickness direction of the conductive particles becomes extremely small due to the pressure at the time of lamination in step 2. For this reason, it is possible to easily electrically connect the first metal substrate and the second metal substrate.

The compression recovery rate of the resin core can be adjusted by, for example, the component of the resin constituting the resin core and the degree of crosslinking of the resin constituting the resin core. Specifically, when the degree of crosslinking of the resin is increased, the compression recovery rate tends to increase, and when the degree of crosslinking of the resin is decreased, the compression recovery rate tends to decrease.

In this specification, compression recovery rate can be measured as follows.

A resin core is spread on the sample table. A load (reverse load value) is applied to one sprayed resin core in the center direction of the resin core using a micro compression tester until the resin core is compressed by 30%. Then, unloading is performed to the load value for origin (0.40 mN). The load-compression displacement between these is measured, and the compression recovery factor can be obtained from the following formula. In addition, the load speed is 0.33 mN/sec. As a micro compression tester, "Fisher Scope H-100" by Fischer, etc. is used, for example.

Compression recovery rate (%)=[(L1-L2)/L1]×100

L1: Compression displacement from the load value for the origin when the load is applied to the reverse load value

L2: Unloading displacement from the reverse load value at the time of unloading to the origin load value

The core substance preferably has a Mohs hardness of 5 or more, more preferably 7 or more, and still more preferably 9 or more.

Examples of the material of the core substance include nickel (Mohs hardness 5), zirconia (Mohs hardness 8-9), alumina (Mohs hardness 9), tungsten carbide (Mohs hardness 9) and diamond (Mohs hardness 10). A core substance may be used individually or may be used in combination of 2 or more types.

The average particle diameter of the core substance is preferably 50 nm or more and 250 nm or less, more preferably 100 nm or more and 200 nm or less. The number of projections formed on the surface of the resin core is preferably 1 or more and 500 or less, more preferably 30 or more and 200 or less.

The conductive layer is preferably made of metal. Examples of the metal constituting the conductive layer include gold, palladium, nickel, copper, silver, tin and aluminum. The metal constituting the conductive layer may be an alloy.

The thickness of the conductive layer is preferably 50 nm or more and 250 nm or less, and more preferably 80 nm or more and 150 nm or less, from the viewpoint of balance between conductivity and economy.

The content of the conductive particles is preferably 0.1 parts by mass or more and 2.0 parts by mass or less, more preferably 0.15 parts by mass or more and 1.8 parts by mass or less, and still more preferably 0.2 parts by mass or more and 1.7 parts by mass or less with respect to 100 parts by mass of the adhesive. desirable.

By setting the content of the conductive particles to 0.1 part by mass or more, the resistance value of the connected body can be easily lowered. Since aggregation of electroconductive particle can be easily suppressed by content of electroconductive particle being 2.0 mass part or less, the resistance value of a connected body can be easily lowered.

<Process 2>

Step 2 is a step of laminating a second metal substrate on the conductive adhesive layer to obtain a connection body having the first metal substrate, the conductive adhesive layer, and the second metal substrate in this order.

2 is a cross-sectional view showing an embodiment of a state after Step 2.

The connection body 100 of FIG. 2 has the conductive adhesive layer 30 and the second metal substrate 20 on the first metal substrate 10 in this order. In FIG. 2 , the first metal substrate 10 and the second metal substrate 20 are electrically connected via conductive particles 30 .

Contrasting FIG. 1 and FIG. 2, the particle diameter of the thickness direction becomes small because the electroconductive particle 30 of FIG. 2 is crushed in the thickness direction. In this way, by crushing the conductive particles in the thickness direction, the adhesive present above the conductive particles (adhesive 31 present above the conductive particles 32 in Fig. 1) is reduced in the width direction by the pressure during lamination. easier to spread with For this reason, the contact area between the conductive adhesive layer and the second metal substrate easily increases, and the interlayer adhesion of the connected body can be easily improved.

At both left and right ends in FIG. 2 , the conductive adhesive layer 30 and the second metal substrate 20 are not in contact. These locations are air bubbles mixed at the time of lamination. As will be described later, air bubbles can be easily reduced by adjusting the temperature during lamination.

Embodiment of the 2nd metal substrate used in process 2 is as above-mentioned.

It is preferable that the adhesive contains a base material and a curing agent, and the lamination temperature in step 2 is equal to or higher than the glass transition temperature of the base material. That is, it is preferable that the lamination temperature of Step 2 and the glass transition temperature of the main material of the adhesive satisfy the following relationship. By satisfying the following relationship, the initial resistance value can be easily lowered, and the temporal increase in the resistance value of the connecting body can be easily suppressed.

The glass transition temperature of the subject of the adhesive ≤ the laminate temperature of step 2

In Step 2, the lamination temperature is preferably 55°C or higher, more preferably 60°C or higher, and still more preferably 70°C or higher. In particular, when the main glass transition temperature of the adhesive is room temperature or higher, it is preferable to set the lamination temperature to 55°C or higher.

By setting the lamination temperature to 55°C or higher, mixing of air bubbles during lamination can be suppressed, and the resistance value can be easily lowered. When air bubbles are mixed during lamination, since it becomes difficult for the adhesive to suppress the restoration of the conductive particles to their original shapes, the resistance value of the connected body may increase with time. For this reason, while being able to lower initial resistance value by making lamination temperature into the said range, the temporal rise of the resistance value of a connection body can be suppressed easily.

The upper limit of the lamination temperature is not particularly limited, but is preferably 110°C or lower, more preferably 100°C or lower, still more preferably 90°C or lower.

The pressure of the laminate in step 2 is preferably 0.1 MPa or more and 1.0 MPa or less, more preferably 0.2 MPa or more and 0.7 MPa or less, and still more preferably 0.3 MPa or more and 0.5 MPa or less.

By setting the pressure to 0.1 MPa or more, it is possible to easily crush the conductive particles in the thickness direction. In addition, by setting the pressure to 0.1 MPa or more, the adhesive present above the conductive particles (adhesive 31 present above the conductive particles 32 in Fig. 1) can be easily spread in the width direction by the pressure during lamination. can

By setting the pressure to 1.0 MPa or less, it becomes unnecessary to apply a high pressure, so that the production of the connected body can be simplified, the production of the connected body is stable, and the connected body can be easily and continuously manufactured. there is.

The lamination speed of step 2 is preferably 0.2 m/min or more and 30 m/min or less, more preferably 0.4 m/min or more and 20.0 m/min or less, and still more preferably 1.0 m/min or more and 15.0 m/min or less.

<Roll to Roll>

In the method for manufacturing a connected body of the present invention, the step 1 is performed by continuously feeding the first metal substrate from the rolled product of the first metal substrate, and the second metal substrate is removed from the rolled product of the second metal substrate. It is preferable to perform the said process 2 by sending out a metal substrate continuously.

By adopting the above means, it is possible to continuously manufacture connected bodies, and the manufacturing efficiency can be dramatically increased.

In addition, you may once wind up the laminated body in which the conductive adhesive layer was formed on the 1st metal substrate after the process 1. And you may perform process 2 by sending out continuously the said 2nd metal base material from the roll-like object of the said 2nd metal base material, while continuously sending out a laminated body from the roll-shaped laminated body which rolled up. Thus, even if it includes the process of winding up a laminated body between process 1 and process 2, since it is manufacture by roll-to-roll, a manufacturing rate can be raised remarkably.

Fig. 3 is a schematic diagram showing an embodiment of a roll-to-roll manufacturing method. In FIG. 3 , step 1 is performed by continuously sending out the first metal substrate 10 from the roll-shaped object 11 of the first metal substrate. In addition, in FIG. 3, process 2 is performed by continuously sending out the 2nd metal substrate 20 from the roll-shaped object 21 of a 2nd metal substrate. In FIG. 3 , steps 1 and 2 are performed continuously on one line.

In addition, as mentioned above, you may once wind up the laminated body in which the conductive adhesive layer was formed on the 1st metal substrate after the process 1. That is, between the process 1 and the process 2, a predetermined time may be vacant.

In FIG. 3, the process after laminating the 2nd metal substrate 20 on the conductive adhesive layer 30 and obtaining the connection body 100 is not described. After laminating the second metal substrate 20 on the conductive adhesive layer 30 to obtain the connected body 100, it is preferable to wind the connected body 100 into a roll shape.

The area of the connected body when viewed from a plane is S, the area of the first metal base when the connected body is viewed from a plane is S1, and the area of the second metal base when the connected body is viewed from a plane is S2 At this time, it is preferable to satisfy the following formulas (1) and (2). By satisfying the following formulas (1) and (2), positional alignment can be made unnecessary. Further, by satisfying the following formulas (1) and (2), it is possible to easily electrically connect the first metal substrate and the second metal substrate.

0.99≤S1/S≤1.01 (1)

0.99≤S2/S≤1.01 (2)

When the area of the conductive adhesive layer when the connection body is viewed in a plan view is S3, it is preferable that the above-described S1 and S2 and S3 satisfy the following formulas (3) and (4). By satisfying the following equations (3) and (4), positional alignment can be made unnecessary. Further, by satisfying the following formulas (3) and (4), it is possible to easily electrically connect the first metal substrate and the second metal substrate.

1.00≤S1/S3≤1.02 (3)

1.00≤S2/S3≤1.02 (4)

<Process 3>

The manufacturing method of the connected body of this invention may further have the following process 3.

Step 3: A step of aging the connected body.

By performing the aging treatment in step 3, the adhesive in the conductive adhesive layer can be cured. For this reason, in the connected body subjected to Step 3, since the adhesive easily suppresses the restoration of the conductive particles to their original shape, the change in the resistance value of the connected body with time can be easily suppressed.

In step 3, the temperature and time of the aging treatment can be appropriately adjusted depending on the type of adhesive to be used, but the following ranges are preferable.

The temperature of the aging treatment is preferably 55°C or lower, more preferably 50°C or lower, and still more preferably 47°C or lower. By setting the temperature of the aging treatment to 55° C. or less, restoration of the conductive particles to their original shapes during the aging treatment can be easily suppressed.

The lower limit of the temperature of the aging treatment is preferably 25°C or higher, more preferably 30°C or higher, and still more preferably 40°C or higher, in order to promote curing of the adhesive.

The time of the aging treatment is not particularly limited, but is preferably 1 day or more and 9 days or less, and more preferably 3 days or more and 7 days or less. When the temperature of the aging treatment is high, the time of the aging treatment is preferably less than one day.

<multiple properties>

The adhesive after Step 3 preferably has a glass transition temperature of -1°C or higher, more preferably 23°C or higher, still more preferably 30°C or higher, still more preferably 40°C or higher. By increasing the glass transition temperature of the adhesive after the aging treatment, the adhesive can easily suppress the restoration of the conductive particles to their original shape, so that the change in the resistance value of the connected body over time can be easily suppressed. The glass transition temperature of the adhesive after Step 3 may be less than -1°C. By setting the glass transition temperature of the adhesive after the aging treatment to less than -1°C, the initial adhesive force between the first metal substrate and the second metal substrate can be increased.

The upper limit of the glass transition temperature of the adhesive after step 3 is not particularly limited, but is preferably 100°C or lower, more preferably 90°C or lower, more preferably 70°C or lower, and more preferably 50°C or lower.

The average thickness of the conductive adhesive layer after step 3 is defined as Tn [μm], and the average diameter of the conductive particles in the thickness direction is defined as Dn [μm]. At this time, it is preferable that Tn and Dn satisfy the relationship of Tn≤Dn.

By satisfying the relationship of Tn≤Dn, the first metal substrate and the second metal substrate can be electrically connected.

The ratio of Dn to Tn (Dn/Tn) is preferably more than 1.00, more preferably 1.01 or more, and still more preferably 1.03 or more. By setting Dn/Tn to more than 1.00, it is possible to easily electrically connect the first metal substrate and the second metal substrate.

The ratio of Dn to Tn (Dn/Tn) is preferably 1.50 or less, more preferably 1.40 or less, and still more preferably 1.30 or less. By making the said ratio into 1.50 or less, the interlayer adhesiveness of a connection body can be easily made good.

The difference between Dn and Tn (Dn-Tn) is preferably more than 0 μm, more preferably 0.01 μm or more, still more preferably 0.03 μm or more, and still more preferably 0.05 μm or more. By setting the difference to more than 0 µm, it is possible to easily electrically connect the first metal substrate and the second metal substrate.

The difference between Dn and Tn (Dn-Tn) is preferably 1.0 μm or less, more preferably 0.8 μm or less, and still more preferably 0.7 μm or less. By making the said difference into 1.0 micrometer or less, the interlayer adhesiveness of a connection body can easily be made good.

In this specification, Tn is the average value of the thickness of the conductive adhesive layer at 30 randomly selected locations. The measurement of the thickness at the above 30 locations shall be performed after Step 3 is completed. The thickness of the above-mentioned 30 locations can be measured from a cross-sectional photograph of the conductive adhesive layer taken by, for example, an SEM or the like. In many cases, Tn substantially coincides with T1 described above.

In this specification, Dn can be measured, for example, in the following B1 and B2 procedures. The following B1 and B2 shall be performed after step 3 is completed. Dn is smaller than the above-mentioned D1.

B1: A cross-sectional photograph of the conductive adhesive layer is taken by SEM or the like.

B2: Measure the diameter in the thickness direction of the conductive particles taken in the cross-sectional photograph. Let the diameter average of the thickness direction of a total of 30 electroconductive particles be Dn.

<resistance value>

The connection body preferably has a resistance value of 10.0 mΩ or less, more preferably 8.0 mΩ or less, and still more preferably 6.0 mΩ or less. The lower limit of the resistance value of the connected body is not particularly limited, but is preferably 1.0 mΩ or more, and more preferably 2.0 mΩ or more.

It is preferable to satisfy the above resistance value after Step 2, and it is more preferable to satisfy after Steps 2 and 3.

The resistance value of the connected body can be measured by the four-terminal method by attaching one terminal to the first metal substrate and attaching the other terminal to the second metal substrate.

[Connection body]

The connection body of the present invention has a first metal substrate, a conductive adhesive layer, and a second metal substrate in this order, and the conductive adhesive layer includes an adhesive and conductive particles having a conductive layer on the surface of a resin core, When the average thickness of the conductive adhesive layer is defined as Tn [μm] and the average diameter of the conductive particles in the thickness direction is defined as Dn [μm], the relationship of Tn≤Dn is satisfied.

By satisfying the relationship of Tn≤Dn, the first metal substrate and the second metal substrate can be electrically connected.

In the connected body of the present invention, the embodiment of the conductive particles having a conductive layer on the surface of the first metal substrate, the second metal substrate, the conductive adhesive layer, the adhesive and the resin core is the production of the above-described connected body of the present invention. It is the same as embodiment of the conductive particle which has a conductive layer on the surface of the 1st metal substrate in a method, a 2nd metal substrate, a conductive adhesive layer, an adhesive agent, and a resin core.

For example, the ratio of Dn to Tn (Dn/Tn) is preferably more than 1.00, more preferably 1.01 or more, and still more preferably 1.03 or more. Further, the ratio of Dn to Tn (Dn/Tn) is preferably 1.50 or less, more preferably 1.40 or less, and still more preferably 1.30 or less.

The difference between Dn and Tn (Dn-Tn) is preferably greater than 0 µm, more preferably greater than 0.01 µm, still more preferably greater than 0.03 µm, and even more preferably greater than 0.05 µm. Further, the difference between Dn and Tn (Dn-Tn) is preferably 1.0 µm or less, more preferably 0.8 µm or less, and still more preferably 0.7 µm or less.

Moreover, it is preferable that S1/S is 0.99 or more and 1.01 or less. It is preferable that S2/S is 0.99 or more and 1.01 or less.

Moreover, it is preferable that S1/S3 is 1.00 or more and 1.02 or less. It is preferable that S2/S3 is 1.00 or more and 1.02 or less.

Moreover, the particle|grains which have a processus|protrusion on the surface of electroconductive particle are preferable.

In addition, the resin core of the conductive particles preferably has a compression recovery rate of 55% or less, more preferably 47% or less, more preferably 40% or less, more preferably 30% or less, more preferably 18% or less. . The resin core preferably has a compression recovery rate of 5% or more, more preferably 6% or more, and still more preferably 7% or more.

The content of the conductive particles is preferably 0.1 part by mass or more and 2.0 parts by mass or less, more preferably 0.15 part by mass or more and 1.0 part by mass or less, and further preferably 0.2 part by mass or more and 0.8 part by mass or less with respect to 100 parts by mass of the adhesive. desirable.

The glass transition temperature of the adhesive is preferably -1°C or higher, more preferably 23°C or higher, still more preferably 30°C or higher, and still more preferably 40°C or higher.

Example

Hereinafter, the present invention will be specifically described by examples, but the present invention is not limited to the following examples.

1. Measure

1-1. Average particle size and thickness

According to the description in the text of the specification, T1 represents the average thickness of the conductive adhesive layer after step 1, D1 represents the average particle diameter of the conductive particles after step 1, Tn represents the average thickness of the conductive adhesive layer after step 3, step 3 Dn representing the diameter average in the thickness direction of the conductive particles after was measured. Since the electroconductive particle of Comparative Example 1 had a nano-level particle diameter, measurement was abbreviate|omitted.

1-2. glass transition temperature

The main glass transition temperatures of the adhesives used in Examples and Comparative Examples were measured. Moreover, about the adhesive used in the Example and the comparative example, the glass transition temperature after the aging process of process 3 was measured. As the measuring device, Hitachi High-Tech Science Co., Ltd. trade name "DSC7000X" was used. Measurement temperature conditions were set at a heating rate of 20°C/min.

1-3. resistance value

Resistance values of the connected bodies prepared in Examples and Comparative Examples were measured. One pair of terminals were attached to the first metal substrate, and the other pair of terminals were attached to the second metal substrate, and the resistance value was measured by the four-terminal method. As the measuring device, "Resistance Meter RM3544", a trade name of Hioki Denki Co., Ltd., was used. The resistance value was measured immediately after step 2 and after step 3. In Comparative Example 1, since the resistance value immediately after step 2 was extremely high, measurement of the resistance value after step 3 was omitted.

1-4. Adhesion (peel force)

Two samples were produced by cutting the connected body fabricated in Examples and Comparative Examples into a width of 15 mm and a length of 10 cm. The second metal substrate of 10 mm from the tip of one sample was peeled off, the peeled second metal substrate was held in a chuck, and using Shimadzu Corporation's trade name "AUTOGRAPH AGS-50D", a peel angle of 180 ° and a peel speed of 200 mm / It peeled under conditions of min, and peel force 1 was measured.

The first metal substrate having a length of 10 mm from the tip of the other sample was peeled off, and the peeled first metal substrate was held by a chuck, using Shimadzu Corporation's trade name "AUTOGRAPH AGS-50D", a peeling angle of 180° and a peeling speed of 200 mm/min. It peeled under conditions of min, and the peel force 2 was measured.

Among peel force 1 and peel force 2, the peel force of the weaker side is shown in Table 1. The peel force of the weak side is a pass level of 0.10 N/mm or more.

2. Production of conductive particles having a conductive layer on the surface of the resin core

2-1. Preparation of conductive particle 1

(1) Production of Polymer Seed Particle Dispersion

2500 g of ion-exchanged water, 250 g of styrene, 50 g of octyl mercaptan, and 0.5 g of sodium chloride were placed in a separable flask, followed by stirring under a nitrogen atmosphere. After that, polymer seed particles were obtained by heating at 70°C, adding 2.5 g of potassium persulfate, and reacting for 24 hours.

5 g of the obtained polymer seed particles, 500 g of ion-exchanged water, and 100 g of a 5% by weight aqueous solution of polyvinyl alcohol were mixed and dispersed by ultrasonic waves, then placed in a separable flask and stirred to obtain a dispersion of polymer seed particles.

(2) Production of resin core

100 g of dimethylol-tricyclodecane dimethacrylate, 90 g of methyl methacrylate, 2.6 g of benzoyl peroxide, 10 g of triethanolamine lauryl sulfate, and 130 g of ethanol were added to 1000 g of ion-exchanged water, stirred, and the emulsion was got it The obtained emulsion was divided into several times, added to the polymer seed particle dispersion, and stirred for 12 hours. Thereafter, 500 g of a 5% by weight polyvinyl alcohol aqueous solution was added, and the mixture was reacted in a nitrogen atmosphere at 85°C for 9 hours to obtain a resin core (average particle diameter: 4.4 µm). The compression recovery rate of the resin core was 46%.

(3) Production of conductive particles

(3-1) Palladium Attachment Step

The obtained resin core was etched and washed with water. Next, the resin core was added and stirred in 100 mL of a palladium-catalyzed liquid containing 8% by weight of a palladium catalyst. After that, it was filtered and washed. The resin core was added to a 0.5% by weight dimethylamine borane solution at pH 6 to obtain a resin core to which palladium adhered.

(3-2) Core material attachment process

The resin core to which palladium adhered was stirred and dispersed for 3 minutes in 300 mL of ion-exchanged water to obtain a dispersion liquid. Next, 1 g of metal nickel particle slurry (average particle diameter of 100 nm) was added to the dispersion over 3 minutes to obtain a resin core with a core substance attached thereto.

(3-3) Electroless nickel plating process

A nickel plating solution (pH 8.5) containing 0.23 mol/L of nickel sulfate, 0.92 mol/L of dimethylamine borane, and 0.5 mol/L of sodium citrate was prepared. 500 mL of ion-exchanged water was added to the resin core with the core substance attached, and the nickel plating solution was gradually added dropwise to the suspension while stirring the obtained suspension at 60°C to perform electroless nickel plating. When a conductive layer (nickel-boron conductive layer containing nickel and boron) having a thickness of about 0.1 μm was formed on the surface of the resin core, dripping of the electroless plating solution was finished. Thereafter, by filtering the suspension to remove particles, washing with water and drying, a nickel-boron conductive layer (96.4 nm in thickness) is provided on the surface of the resin core, and conductive particles having protrusions on the surface of the nickel-boron conductive layer. 1 was obtained (average particle diameter of 4.5 µm).

2-2. Production of conductive particles 2

In accordance with the description of Example 3 of Japanese Unexamined Patent Publication No. 2020-97739, conductive particles 2 in which a conductive layer (nickel layer) having a thickness of about 0.1 μm was formed on the surface of a resin core (compression recovery rate: 9.8%) were obtained ( Average particle diameter 3.1 μm).

3. Fabrication of connecting body

[Example 1]

Through the following steps 1 to 3, the connected body of Example 1 was produced.

Step 1: On a first metal substrate (aluminum having a thickness of 50 μm), the following coating liquid 1 for a conductive adhesive layer was applied by a gravure coating method. Then, it was dried at 100°C for 1 minute to form a conductive adhesive layer having an average thickness of 4.0 µm. Step 1 was performed continuously by sending out the first metal substrate continuously as a roll-shaped article of the first metal substrate.

<Coating liquid 1 for conductive adhesive layer>

・0.54 parts by mass of the conductive particles 1 prepared in “2-1” above

31.3 parts by mass of the main adhesive

(Polyester-based resin)

(Toyobo Co., Ltd., brand name: Byron GK810, solid content 100% by mass)

・ 2.64 parts by mass of the curing agent for the adhesive

(Isocyanate-based compound)

(Tosoh Corporation, brand name: Coronate HX, solid content 100% by mass)

・Appropriate amount of diluted solvent

Process 2: The 2nd metal substrate was laminated on the conductive adhesive layer, and the connection body which had the 1st metal substrate, the conductive adhesive layer, and the 2nd metal substrate in this order was obtained. The lamination conditions were as follows.

Step 2 was performed continuously by continuously sending out the second metal substrate from the roll-shaped object of the second metal substrate. Process 1 and process 2 were implemented continuously in one line.

<Laminate conditions>

・Temperature of lamination roll: 60°C

Laminate pressure: 0.4 MPa

Laminate speed: 0.8 m/min

Step 3: The connected body obtained in Step 2 was wound up and subjected to aging treatment at 45°C for 5 days.

[Example 2]

A connected body of Example 2 was produced in the same manner as in Example 1, except that the addition amount of the conductive particles in the coating liquid for conductive adhesive layers 1 was changed to 0.20 parts by mass.

[Example 3]

A connected body of Example 3 was produced in the same manner as in Example 1, except that the coating liquid 1 for conductive adhesive layers was changed to the following coating liquid for conductive adhesive layers 2.

<Coating liquid 2 for conductive adhesive layer>

・1.1 parts by mass of the conductive particles 1 produced in “2-1” above

100 parts by mass of the main adhesive

(Polyester-based resin)

(Doagosei Co., Ltd., brand name: Alpon UH2170, solid content 52% by mass)

12.3 parts by mass of the curing agent for the adhesive

(Isocyanate-based compound)

(Tosoh Corporation, brand name: Coronate HX, solid content 100% by mass)

・Appropriate amount of diluted solvent

[Example 4]

The conductive adhesive layer coating liquid 1 was changed to the following conductive adhesive layer coating liquid 3, and the average thickness of the conductive adhesive layer was changed to 2.9 μm. did

<Coating liquid for conductive adhesive layer 3>

・0.24 parts by mass of the conductive particles 2 prepared in “2-2” above

100 parts by mass of the main adhesive

(Polyester-based resin, glass transition temperature: 0°C)

(Toyo Moton Co., Ltd., brand name: AD76P1, solid content 51% by mass)

・10.0 parts by mass of the curing agent for the adhesive

(Isocyanate-based compound)

(Toyo Moton Co., Ltd., trade name: CAT10L, solid content 53% by mass)

・Appropriate amount of diluted solvent

[Example 5]

A connected body of Example 5 was produced in the same manner as in Example 1, except that the coating liquid 1 for conductive adhesive layers was changed to the following coating liquid 4 for conductive adhesive layers.

<Coating liquid 4 for conductive adhesive layer>

・0.24 parts by mass of the conductive particles 1 prepared in “2-1” above

100 parts by mass of the main adhesive

(Polyester-based resin)

(Toyo Moton Co., Ltd., brand name: AD76P1, solid content 51% by mass)

・10.0 parts by mass of the curing agent for the adhesive

(Isocyanate-based compound)

(Toyo Moton Co., Ltd., trade name: CAT10L, solid content 53% by mass)

・Appropriate amount of diluted solvent

[Example 6]

The conductive adhesive layer coating liquid 1 was changed to the following conductive adhesive layer coating liquid 5, and the aging conditions in step 3 were changed to the following conditions. did

<Coating liquid 5 for conductive adhesive layer>

・0.20 parts by mass of the conductive particles 1 prepared in “2-1” above

・Subject 1 of adhesive 30 parts by mass

(Polyimide resin)

(Arakawa Chemical High School, product name: PIAD200, solid content 30% by mass)

・Subject 2 of adhesive 70 parts by mass

(Polyimide resin)

(Arakawa Chemical High School, brand name: PIAD150H, solid content 30% by mass)

・Subject 3 of adhesive 2.3 parts by mass

(epoxy resin)

(Mitsubishi Chemical Co., Ltd., trade name: jER630, solid content 100% by mass)

・ 8.0 parts by mass of the curing agent for the adhesive

(active ester compound)

(DIC company, brand name: HPC-8000, solid content 65% by mass)

・Curing accelerator 0.0025 parts by mass

(Shikoku Kasei, trade name; Curesol 2E4MZ-a)

・Appropriate amount of diluted solvent

<Process 3>

The connected body obtained in step 2 was wound up and subjected to aging treatment at 160°C for 1 hour.

[Example 7]

The conductive adhesive layer coating liquid 1 was changed to the following conductive adhesive layer coating liquid 6, and the aging conditions in step 3 were changed to the following conditions. did

<Coating liquid 6 for conductive adhesive layer>

・0.10 parts by mass of the conductive particles 1 prepared in “2-1” above

100 parts by mass of subject 1 of adhesive

(Polyimide resin)

(Arakawa Chemical High School, brand name: PIAD152H, solid content 42% by mass)

・Subject 2 of adhesive 11.5 parts by mass

(epoxy resin)

(Mitsubishi Chemical Co., Ltd., trade name: YL980, solid content 100% by mass)

・ 12.8 parts by mass of the curing agent for the adhesive

(phenolic compounds)

(Arakawa Chemical High School, brand name: Tamanol 759, solid content 100% by mass)

・Curing accelerator 0.24 parts by mass

(Shikoku Kasei, trade name: Curesol 2E4MZ)

・Appropriate amount of diluted solvent

<Process 3>

The connected body obtained in step 2 was wound up and subjected to aging treatment at 120°C for 2 hours.

[Comparative Example 1]

A connected body of Comparative Example 1 was produced in the same manner as in Example 1, except that the coating liquid 1 for conductive adhesive layers was changed to the following coating liquid 7 for conductive adhesive layers.

<Coating liquid for conductive adhesive layer 7>

・Carbon black dispersion 115.3 parts by mass

(Mikuni Shikiso Co., Ltd., brand name: RK046, solid content 26.5% by mass)

100 parts by mass of the main adhesive

(Polyester-based resin)

(Toyo Moton Co., Ltd., brand name: AD76P1, solid content 51% by mass)

・ 10 parts by mass of the curing agent for the adhesive

(Isocyanate-based compound)

(Toyo Moton Co., Ltd., trade name: CAT10L, solid content 53% by mass)

・Appropriate amount of diluted solvent

[Comparative Example 2]

A connected body of Comparative Example 2 was produced in the same manner as in Example 1, except that the average thickness of the conductive adhesive layer was changed to 7.0 µm.

As is clear from the results of Table 1, in the manufacturing method of the connected body of the examples, both immediately after manufacturing the connected body (immediately after step 2) and after the aging treatment of the connected body (after step 3), It can be seen that the resistance value can be lowered. Moreover, since the manufacturing method of the connected body of an Example is roll-to-roll manufacturing, manufacturing efficiency can be improved remarkably. Although not described in the tables, all of S1/S, S2/S, S1/S3, and S2/S3 in the body of the specification are 1.00.

10: first metal substrate
11: Roll-shaped article of first metal substrate
20: second metal substrate
21: Roll-shaped article of second metal substrate
30: conductive adhesive layer
31: glue
32: conductive particles having a conductive layer on the surface of the resin core
50: laminate
100: connection body
200: application device

Claims (17)

The manufacturing method of the connected body which has the following process 1-2.
Step 1: A step of forming a conductive adhesive layer by applying an adhesive and a coating liquid for a conductive adhesive layer containing conductive particles having a conductive layer on the surface of a resin core on a first metal substrate, followed by drying. In Step 1, when the average thickness of the conductive adhesive layer is defined as T1 [μm] and the average particle diameter of the conductive particles is defined as D1 [μm], the relationship of T1 < D1 is satisfied.
Process 2: The process of laminating a 2nd metal substrate on the said conductive adhesive layer, and obtaining the connection body which has the said 1st metal substrate, the said conductive adhesive layer, and the said 2nd metal substrate in this order. The method for manufacturing a connected body according to claim 1, wherein the resin core has a compression recovery rate of 5% or more and 55% or less. The method for manufacturing a connected body according to claim 1, wherein the conductive particles are contained in an amount of 0.1 part by mass or more and 2.0 parts by mass or less with respect to 100 parts by mass of the adhesive. The method for manufacturing a connected body according to claim 1, wherein the adhesive contains a base material and a curing agent, and the base material has a glass transition temperature of -5°C or higher in step 1. The method for manufacturing a connected body according to claim 1, wherein the adhesive contains a base material and a curing agent, and the lamination temperature in step 2 is equal to or higher than the glass transition temperature of the base material. The method for manufacturing a connected body according to claim 1, further comprising the following step 3.
Step 3: A step of aging the connected body. The method for manufacturing a connected body according to claim 6, wherein in step 3, the temperature of the aging treatment is 55°C or lower. The method for manufacturing a connected body according to claim 6, wherein the glass transition temperature of the adhesive after Step 3 is -1°C or higher. The connection according to claim 6, which satisfies the relationship of Tn≤Dn when the average thickness of the conductive adhesive layer after step 3 is defined as Tn [μm] and the average diameter of the conductive particles in the thickness direction is defined as Dn [μm]. How to make a sieve. The method according to claim 1, wherein step 1 is performed by continuously sending out the first metal substrate from the roll-like product of the first metal substrate, and continuously feeding the second metal substrate from the roll-like product of the second metal substrate. The manufacturing method of the connected body which performs the said process 2 by sending out to. A first metal substrate, a conductive adhesive layer and a second metal substrate in this order, the conductive adhesive layer comprising an adhesive and conductive particles having a conductive layer on the surface of a resin core, the average thickness of the conductive adhesive layer A connection body in which Dn/Tn satisfies the relationship of greater than 1.00 when Tn [μm] and the average of the diameters in the thickness direction of the conductive particles are defined as Dn [μm]. The connected body according to claim 11, wherein Dn/Tn satisfies a relationship of 1.01 or more and 1.50 or less. The method of claim 11, wherein the area of the connection body when viewed from a plane is S, the area of the first metal substrate when the connection body is viewed from a plane is S1, and the second metal substrate when the connection body is viewed from a plane A connected body that satisfies the following formulas (1) and (2) when the area of is S2.
0.99≤S1/S≤1.01 (1)
0.99≤S2/S≤1.01 (2) The conductive adhesive according to claim 11, wherein S1 is the area of the first metal substrate when the connection body is viewed from a plane, and S2 is the area of the second metal substrate when the connection body is viewed from a plane. A connection body that satisfies the following formulas (3) and (4) when the area of the layer is set to S3.
1.00≤S1/S3≤1.02 (3)
1.00≤S2/S3≤1.02 (4) The connected body according to claim 11, wherein the resin core has a compression recovery rate of 5% or more and 55% or less. The connected body according to claim 11, which contains 0.1 parts by mass or more and 2.0 parts by mass or less of the conductive particles with respect to 100 parts by mass of the adhesive. The connected body according to claim 11, wherein the adhesive has a glass transition temperature of -1°C or higher.

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