JPH05347464A - Connecting structure of electric circuit board and connecting method therefor - Google Patents

Abstract

PURPOSE:To electrically connect with high reliability by interposing insulating particles between electrodes of first, second electric circuit boards. CONSTITUTION:A second electric circuit board 2 is held fixedly to a first electric circuit board 1 with adhesive (e.g. ultraviolet curable adhesive) 3, and electrodes 1a, 2a of the boards 1, 2 are electrically connected therebetween, for example, with conductive particles 4 covered with conductive members 4b made of nickel, gold, platinum, etc. In this case, an insulator 5 made of elastic material 4a such as polystyrene, silicone rubber, styrene-butadiene rubber, thermoplastic polyester, epoxy resin, urethane resin, etc., is interposed between the electrodes 1a and 2a of the boards 1, 2. Thus, collapsing width of the particles 4a is suitable, they can be connected with a predetermined connecting thickness, and electric connection with high reliability can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure and a connection method for an electric circuit board, and more specifically, an electric circuit board on which a semiconductor element such as an IC is formed, or an electric circuit board on which a liquid crystal display section is mounted. The present invention relates to a connection structure and a connection method for an electric circuit board, which is preferably implemented to electrically connect a printed circuit board, a flexible board, or a circuit board such as a ceramic board.

[0002]

2. Description of the Related Art Recently, with the miniaturization and thinning of electronic devices, the necessity of connecting fine electric boards to each other or connecting a minute portion to a fine electric board has been dramatically increased. Various measures have been taken to connect these electric boards with high precision. As a conventional connection structure for this kind of electric circuit board, there are, for example, those described in JP-A-2-204918 and JP-A-3-101007. In these products, two kinds of conductive particles are contained in the insulating adhesive, and the crush width of the elastic particles is controlled by the hard particles, so that the connection thickness between the substrates is made constant and good electrical connection is made. I am trying. Particularly, the one described in Japanese Patent Laid-Open No. 3-101007 is composed of conductive particles in which resin particles having elasticity are coated with a conductive member.

After the conductive particles are interposed between the electric boards together with the adhesive, the electric circuit boards are electrically connected by pressure bonding or thermocompression bonding using a head. I am trying.

[0004]

However, in such a conventional connecting structure for an electric circuit board, since the insulating adhesive contains two kinds of conductive particles, the electric circuit board is attached by pressure bonding. When connected, the conductive particles were too crushed or destroyed by the impact of the pressure head, and the substrates could not be connected well. In particular, in the case where the conductive particles are composed of the resin particles having elasticity coated with the conductive member, when the conductive particles are excessively crushed, the conductive member to be coated is cracked to increase the connection resistance. If it is damaged or destroyed, the scattered conductive member causes a defect such as a short circuit between adjacent electrodes.

In order to solve such a problem, it is conceivable to slow down the descending speed of the head to reduce the impact of the pressure head, but in this case, the connection time of the electric circuit board is very long. Therefore, there is a problem that the manufacturing cost of the electric circuit board increases. On the other hand, when the electric circuit board is connected by thermocompression bonding, the elastic particles are easily softened by heat, so that the load is concentrated on the hard particles, resulting in an increase in connection resistance and a short circuit between adjacent electrodes. was there.

Therefore, according to the first aspect of the present invention, by placing insulating particles together with conductive particles between the electrodes of the first and second electric circuit boards, the impact of the pressure head at the time of crimp connection is achieved. A connection structure of an electric circuit board, which can prevent the conductive particles from being broken due to the like, can be connected with a proper crushed width of the conductive particles and with a constant connection thickness, and can perform highly reliable electrical connection. Is intended to provide.

According to a second aspect of the invention, the pressure head is made by making the particle size of the insulating particles before the first and second electric circuit boards are connected to be equal to or larger than the particle size of the conductive particles. It is an object of the present invention to provide a highly reliable connection structure for an electric circuit board, which can alleviate damage due to impact. In the invention according to claim 3, when the insulating particles are deformed after the first and second electric circuit boards are connected,
By making the particle short diameter equal to or smaller than the particle diameter of the conductive particles before both circuit boards are connected, the connection structure of the electric circuit board that ensures reliable connection between the electrodes by the conductive member after connection Is intended to provide.

According to a fourth aspect of the present invention, the insulating particles are made of an elastic body, and the elastic modulus of the insulating particles is set to be smaller than that of the conductive particles, so that the connection of a reliable electric circuit board having a constant connection thickness is achieved. It is intended to provide a structure.
According to the invention of claim 5, the restoring force of the whole conductive particles after the first and second electric circuit boards are connected is made larger than the restoring force of the whole insulating particles, so that the conductive particles are stabilized after the connection. It is intended to provide a highly reliable connection structure of an electric circuit board which can be interposed between electrodes.

According to a sixth aspect of the present invention, the insulating particles are made of an elastic material, and the elastic modulus of the insulating particles is made smaller than that of the first and second electric substrates and the electrodes thereof. An object of the present invention is to provide a highly reliable connection structure for an electric circuit board, which can suppress cracks in the electrodes. The invention according to claim 7 is configured such that the conductive particles have an elastic body as a core and the elastic body is coated with a conductive member. It is an object of the present invention to provide a highly reliable connection structure of an electric circuit board which can be connected in a deformed state) and has a constant connection thickness.

According to an eighth aspect of the present invention, the conductive particles are connected to the first and second electric circuit boards in an elastically deformed state and in a plastically deformed state or a broken state in which the insulating particles exceed the elastic limit. For the purpose of providing a highly reliable electrical circuit board connection structure in which the insulating particles can remove the force of expanding the electrodes after connection and the conductive particles and the electrodes are connected in a stable state. There is.

It is an object of the present invention to provide a connection structure for an electric circuit board, which has a high adhesive strength, by forming the insulating particles from a thermoplastic polymer.
According to the invention of claim 10, by constituting the adhesive from an ultraviolet curing adhesive, the temperature dependence of the elastic modulus of the particles or the substrate can be ignored, and the types of particles or the substrate that can be selected can be increased. It is an object of the present invention to provide a connection structure for an electric circuit board that can be used.

It is an object of the present invention to provide a method of connecting electric circuit boards, which can be easily manufactured with a high yield. The invention according to claim 12 can eliminate the need for temperature control, can be easily manufactured with a high yield, and
It is an object of the present invention to provide a method for connecting electric circuit boards, which can increase the intensity of ultraviolet rays and can be manufactured in a short time.

[0013]

The invention according to claim 1 is
In order to solve the above problems, the second electric circuit board is held and fixed to the first electric circuit board by an adhesive, and the electrodes of the first and second electric circuit boards are electrically connected via conductive particles. In the connection structure of the electric circuit boards that are electrically connected, insulating particles are interposed between the electrodes of the first and second electric circuit boards.

In order to solve the above problems, the particle size of the insulating particles before the first and second electric circuit boards are connected is equal to that of the conductive particles. It is characterized by the above. According to a third aspect of the present invention, in order to solve the above-mentioned problems, the insulating particles are
And the second electric circuit board is deformed after being connected, and the particle short diameter is equal to or smaller than the particle diameter of the conductive particles before the two circuit boards are connected.

In order to solve the above-mentioned problems, the invention according to claim 4 is characterized in that the insulating particles are composed of an elastic body, and the elastic modulus thereof is smaller than that of the conductive particles. In order to solve the above-described problems, the restoring force of the whole conductive particles after the first and second electric circuit boards are connected is larger than the restoring force of the whole insulating particles. Is characterized by.

According to a sixth aspect of the present invention, in order to solve the above-mentioned problems, the insulating particles are composed of an elastic body, and the elastic modulus thereof is higher than the elastic modulus of the first and second electric substrates and the electrodes thereof. It is characterized by being small. In order to solve the above problems, the invention according to claim 7 is characterized in that the conductive particles have an elastic body as a core and the elastic body is covered with a conductive member.

In order to solve the above-mentioned problems, the first and second aspects of the present invention are such that the conductive particles are in an elastically deformed state and the insulating particles are in a plastically deformed state or a fractured state in which the elastic limit is exceeded. The electric circuit board is connected. In order to solve the above problems, the invention according to claim 9 is characterized in that the insulating particles are made of a thermoplastic polymer.

In order to solve the above-mentioned problems, the invention according to claim 10 is characterized in that the adhesive is composed of an ultraviolet curing adhesive. In order to solve the above-mentioned problems, the invention according to claim 11 is the method for connecting an electric circuit board according to any one of claims 1 to 9, wherein thermosetting is performed on the electrode terminal portion of the first electric circuit board. Of a conductive or thermoplastic adhesive, conductive particles, and insulating particles, and then aligning the electrodes of the first electric circuit board with the electrodes of the second electric circuit board; A step of pressurizing the electric circuit board and the second electric circuit board with a heating head to thermally cure the adhesive.

In order to solve the above-mentioned problems, the invention according to claim 12 is the method for connecting an electric circuit board according to any one of claims 1 to 9, wherein the electrode terminal portion of the first electric circuit board is provided. A step of aligning the electrodes of the first electric circuit board and the electrodes of the second electric circuit board after disposing the ultraviolet curable adhesive, the conductive particles, and the insulating particles, and the first electric circuit board. The step of irradiating the ultraviolet curable adhesive with ultraviolet rays while applying pressure to the second electric circuit board with a head to cure the adhesive, is characterized in that.

[0020]

According to the first aspect of the invention, the insulating particles as well as the conductive particles are interposed between the electrodes of the first and second electric circuit boards. Therefore, the impact of the pressure head at the time of pressure-bonding connection is alleviated by the deformation of the insulating particles, and the conductive particles have a proper crush width and are connected with a constant connection thickness. Therefore, unlike the conventional case, there is no occurrence of defects such as an increase in connection resistance value due to excessive crushing of conductive particles and a short circuit between adjacent electrodes due to conductive members scattered due to destruction of conductive particles.
As a result, highly reliable electrical connection is achieved. Further, since the defect due to the impact of the pressure head is prevented, the descending speed of the pressure head is increased and the connection time of the substrate is shortened.

According to the second aspect of the invention, the first and second aspects are provided.
The particle size of the insulating particles before the electric circuit board is connected is equal to or larger than the particle size of the conductive particles. Therefore, after the impact of the pressure head at the time of pressure-bonding connection is alleviated by the deformation of the insulating particles, pressure is applied to the conductive particles, and the conductive particles are appropriately crushed (elastically deformed). As a result, highly reliable electrical connection is achieved.

According to a third aspect of the invention, the first and second aspects are provided.
When the insulating particles are deformed after the electric circuit boards are connected, the particle short diameter is equal to or smaller than the particle diameter of the conductive particles before the two circuit boards are connected. Therefore, after the connection, the electrodes are surely connected by the conductive member, and a highly reliable connection structure of the electric circuit board can be obtained. In the invention according to claim 4, the insulating particles are made of an elastic body, and the elastic modulus thereof is smaller than that of the conductive particles. Therefore, after the insulating particles are sufficiently deformed to reduce the impact of the pressure head, pressure is applied to the conductive particles to connect them with an appropriate collapse width. As a result, the connection thickness becomes constant, an electrical connection with a stable connection resistance value is obtained, and a highly reliable connection structure for an electric circuit board is obtained. This is because the insulating particles having a large elastic modulus do not apply proper pressure to the conductive particles.

According to a fifth aspect of the invention, the first and second aspects are provided.
The restorative force of the whole conductive particles after the electric circuit board is connected is larger than the restorative force of the whole insulating particles. Therefore, after the connection, the conductive particles are stably interposed between the electrodes, and the electrical connection has a stable connection resistance. As a result,
A highly reliable electric circuit board connection structure can be obtained. In the invention according to claim 6, the insulating particles are composed of an elastic body,
The elastic moduli are smaller than the elastic moduli of the first and second electric substrates and their electrodes. Therefore, cracks on the substrate and electrodes due to the insulating particles are suppressed, and a highly reliable connection structure for an electric circuit board can be obtained. It is particularly effective when the electric circuit board is a flexible board such as a polymer film.

According to a seventh aspect of the present invention, the conductive particles are composed of an elastic body as a core and the elastic body coated with a conductive member. Therefore, even when the insulating particles are broken, the connection is made in a proper collapsed state (elastically deformed state). As a result, a highly reliable connection structure for an electric circuit board can be obtained with a constant connection thickness. In the invention according to claim 8, the conductive particles connect the first and second electric circuit boards in an elastically deformed state and in a plastically deformed state or a broken state in which the insulating particles exceed the elastic limit. Therefore, the force that the insulating particles try to spread between the electrodes after connection disappears,
A highly reliable electrical circuit board connection structure in which the conductive particles and the electrodes are connected in a stable state can be obtained.

According to the invention of claim 9, the insulating particles are composed of a thermoplastic polymer. Therefore, the insulating particles are heated and flowed to be integrated with the adhesive. As a result, a connection structure of an electric circuit board having high adhesive strength can be obtained. In the invention of claim 10, the adhesive is composed of an ultraviolet curable adhesive. Therefore, the temperature dependence of the elastic modulus of the particles or the substrate can be ignored, and the types of particles or substrates that can be selected are increased.

In the eleventh aspect of the present invention, after the thermosetting or thermoplastic adhesive, the conductive particles, and the insulating particles are arranged on the electrode terminal portion of the first electric circuit board, the first electric circuit is formed. The electrodes of the circuit board and the electrodes of the second electric circuit board are aligned, then the first electric circuit board and the second electric circuit board are pressed by a heating head, and the adhesive is thermally cured. It has become so. Therefore, the electric circuit boards are easily connected with high yield, and the manufacturing cost thereof is reduced.

According to the twelfth aspect of the present invention, the ultraviolet curable adhesive, the conductive particles, and the conductive particles are provided on the electrode terminal portion of the first electric circuit board.
And after the insulating particles are arranged, the electrodes of the first electric circuit board and the electrodes of the second electric circuit board are aligned,
Then, the ultraviolet curing adhesive is irradiated with ultraviolet rays while the electrodes of the first electric circuit board and the second electric circuit board are pressed by the heating head, whereby the adhesive is cured. Therefore, the electric circuit boards are easily connected with high yield, and the manufacturing cost thereof is reduced. If the intensity of ultraviolet rays is increased, the electric circuit board can be connected in a short time.

[0028]

EXAMPLES The present invention will be described below based on examples.
1 and 2 are views showing a first embodiment of a connection structure and a connection method for an electric circuit board according to the present invention.
It corresponds to 12. 1A shows a connection structure of an electric circuit board, FIG. 1B shows a state before connecting the electric circuit board, and FIGS. 2A to 2C show a connection method of the electric circuit board. Showing.

First, the structure will be described. In FIG.
Reference numerals 1 and 2 denote a first electric circuit board having electrodes 1a and 1b, respectively, a second electric circuit board, 3 denotes an ultraviolet curing adhesive for connecting and holding the second circuit board 2 to the first circuit board 1, and 4
Are conductive particles and 5 are insulating particles. UV curable adhesive 3
Is composed of an acrylic oligomer, an acrylic monomer, a one-component adhesive such as a photopolymerization initiator such as benzophenone. The conductive particles 4 are composed of an elastic body 4a as a core and the elastic body 4a covered with a conductive member 4b. Specifically, the elastic body 4a is made of polystyrene, silicone rubber, or styrene-butadiene rubber. , Thermoplastic polyester, epoxy resin, urethane resin, etc., and the conductive member 4b is made of nickel, gold, platinum, etc. The conductive member 4b is coated on the elastic body 4a with a uniform thickness by electrolytic plating, and the coating thickness is set to 0.05 to 1.0 μm.

As shown in FIG. 1 (b), the particle size of the insulating particles 5 before the electric circuit boards 1 and 2 are connected is equal to or larger than the particle size of the conductive particles 4, and The insulating particles 5 are deformed after the electric circuit boards 1 and 2 are connected, and the particle short diameter is formed to be equal to or smaller than the particle diameter of the conductive particles before the circuit boards 1 and 2 are connected. Has been done.

Next, based on FIG. 2, electric circuit boards 1, 2
A method of connecting the will be described. First, as shown in FIG. 2A, the ultraviolet curable adhesive 3 is applied or transferred onto the electrode end portion of the first electric circuit board 1, and then the conductive particles 4 and the insulating particles 5 are dispersed. Then, as shown in FIG. 2B, the electrode 1a of the electric circuit board 1 and the electrode 2a of the second electric circuit board 2 are aligned with each other. For this alignment, it is preferable to use a method in which the electrodes 1a and 2a are overlapped by optical alignment, or alignment marks are provided on the substrates 1 and 2, and the alignment marks are recognized by image processing and aligned.

Next, as shown in FIG. 2 (c), pressure is applied from the substrate 2 side by a pressure head (not shown) as indicated by an arrow, and ultraviolet rays are emitted from the substrate 1 side by an ultraviolet irradiation device (not shown) as indicated by an arrow. Irradiate. In this pressure-bonding connection, after the impact of the pressure head is alleviated by the deformation of the insulating particles 5, pressure is applied to the conductive particles 4, and the conductive particles are appropriately crushed (elastically deformed). Then, when the conductive particles 4 are in an appropriate collapsed state, the conductive member 4 reliably connects the electrodes 1a, 2a.

As described above, in the embodiment, the electric circuit board 1,
Since the insulating particles 5 are interposed together with the conductive particles 4 between the two electrodes 1a and 2a, the impact of the pressure head at the time of pressure-bonding connection can be alleviated by the deformation of the insulating particles. It is possible to connect the substrates 1 and 2 so that the crushed width is appropriate and the connection thickness is constant. For this reason, increase in connection resistance value due to excessive crushing of conductive particles, as in the conventional case,
A defect such as a short circuit between adjacent electrodes due to the conductive member scattered by the destruction of the conductive particles does not occur. As a result, highly reliable electrical connection can be achieved. Further, since it is possible to prevent a defect due to the impact of the pressure head, it is possible to increase the descending speed of the pressure head and shorten the connection time of the substrates.

Further, since the particle size of the insulating particles 5 before the electric circuit boards 1 and 2 are connected is made equal to or larger than the particle size of the conductive particles 4, the impact of the pressure head at the time of crimping connection. After being relaxed by the deformation of the insulating particles 5, pressure can be applied to the conductive particles 4, and the conductive particles 4 can be brought into an appropriate collapsed state (elastically deformed state). As a result, highly reliable electrical connection can be achieved.

When the insulating particles 5 are deformed after the electric circuit boards 1 and 2 are connected, the particle diameter of the particle short diameter 5 is calculated as the particle diameter of the conductive particles 4 before the circuit boards 1 and 2 are connected. Since it is equal to or less than, it is possible to reliably connect the electrodes 1a and 2a by the conductive member 4 after the connection, and it is possible to obtain a highly reliable connection structure of the electric circuit board. Further, since the conductive particles 4 have the elastic body 4a as the core and the elastic body 4a is coated with the conductive member 4b, the insulating particles 5 are connected in a proper crushed state even when they are destroyed. Therefore, it is possible to obtain a highly reliable connection structure of an electric circuit board with a fixed connection thickness.

Furthermore, since the adhesive is composed of the ultraviolet curing adhesive 3, the temperature dependence of the elastic modulus of the particles or the substrate can be ignored, and the types of particles or substrates that can be selected can be increased. . Since both boards 1 and 2 are connected by the method described above, the electric circuit boards 1 and 2 are connected.
Can be connected easily and with high yield, and the manufacturing cost thereof can be reduced. Further, if the intensity of ultraviolet rays is increased, both substrates 1 and 2 can be connected in a short time.

As another mode of the insulating particles 5,
The insulating particles are made of an elastic material, and the elastic modulus of the insulating particles is set to be that of the conductive particles 4.
It may be smaller than the elastic modulus of. In this case, the elastic material is polystyrene or divinylbenzene cross-linked copolymer, silicone rubber,
It may be made of styrene-butadiene rubber, thermoplastic polyester, epoxy resin, urethane resin, or the like. By doing so, the insulating particles can be sufficiently deformed to reduce the impact of the pressure head, and then the conductive particles 4 can be connected by applying a pressure by applying a pressure. As a result, the connection thickness becomes constant, an electrical connection with a stable connection resistance value can be obtained, and a highly reliable connection structure for an electric circuit board can be obtained. On the other hand, when the elastic modulus of the insulating particles is large, the conductive particles are not properly pressured.

In another embodiment, the conductive particles 4 and the insulating particles 5 are made so that the restoring force of the entire conductive particles 4 after the electric circuit boards 1 and 2 are connected is made larger than the restoring force of the entire insulating particles 5. The material and the connection conditions of the substrates 1 and 2 may be selected. That is, the particle diameter D of the conductive particles 4 and the insulating particles 5, the particle diameter distribution (particle diameter average Da, standard deviation σ), elastic modulus E, crush strain rate K, Poisson's ratio ν, particle dispersion density N, and electric circuit board. The above materials and the distance between the electrodes are determined so that the relationship of the distance A between the first and second electrodes 1a and 2a satisfies the following condition. F conductive particles> F insulating particles However, F is set by the following formula.

[0039]

[Equation 1]

The above f (D) is a probability distribution function of normal distribution, and P (D) is obtained from the Hertz elastic formula, and represents the force generated when the elastic sphere is compressed. Based on this formula, for example, between the electrode circuit boards 1 and 2 having an electrode width of 0.15 mm, the number of electrodes of 160, and a connection width of 2 mm, insulating particles made of a material of divinylbenzene, E = 488 kgf / mm ² , ν = 0.38. D
a = 8 μm, σ = 0.1 μm, N = 60 particles / mm ² , and Ni-plated conductive particles Da = 9 μm, σ = 0.15 μm, N = 10 particles / m
When m ² is interposed and A = 7.7 μm is connected, F insulating particles = 2.4 kgf and F conductive particles = 13 kgf, and a good connection structure can be obtained.

In another embodiment, the insulating particles are made of an elastic material, and the elastic modulus of the insulating particles is made smaller than that of the first and second electric substrates 1 and 2 and the electrodes 1a and 2a thereof. Is also good. By doing this, it is possible to suppress cracks on the substrate or electrode due to insulating particles,
A highly reliable electrical circuit board connection structure can be obtained. This is especially effective when the electric circuit boards 1 and 2 are made of flexible substrates such as polymer films.

In another embodiment, the conductive particles are
The electric circuit boards 1 and 2 may be connected in an elastically deformed state and in a plastically deformed state or a broken state in which the insulating particles exceed the elastic limit boundary. By doing so, it is possible to remove the force that the insulating particles try to spread between the electrodes after connection, and obtain a highly reliable connection structure of the electric circuit board in which the conductive particles and the electrodes are connected in a stable state. be able to.

In another embodiment, the insulating particles may be made of thermoplastic polymer. In this case, the thermoplastic polymer resin may be composed of thermoplastic polyester, thermoplastic elastomer, styrene-butadiene rubber, polyvinyl butylate, or the like. By doing so, the insulating particles can be heated and flowed at the time of bonding, and can be integrated with the adhesive. As a result, it is possible to obtain a connection structure for an electric circuit board having high adhesive strength.

FIG. 3 is a diagram showing a second embodiment of the connection structure and the connection method of the electric circuit board according to the present invention.
It corresponds to 11. The present embodiment is the same as the first embodiment except that a thermosetting or thermoplastic adhesive is used as the adhesive, and the other configurations are the same. Therefore, the same numbers are given to the same configurations. And the description is omitted. As shown in FIG. 3A, the connection structure of the electric circuit board of the present embodiment is as follows.
The adhesive 11 in which the conductive particles 4 and the insulating particles 5 are dispersed is placed on the electric substrate 1. As a method of arranging in this way, the conductive particles 4 and the insulating particles 5 are mixed and dispersed in the adhesive 11, and sandwiched with a release film or a thermoplastic film to prepare an anisotropic conductive film, and the conductive film is formed. The electrodes 1a and 2a may be arranged, or the conductive particles 4 and the insulating particles 5 may be dispersed after the adhesive 11 is applied or transferred onto the electrodes 1a and 2a.

As the adhesive 11, a thermosetting or thermoplastic adhesive is used. As the material thereof, epoxy resin type, polyurethane type, acrylic resin type or the like may be used. Next, as shown in FIG. 3B, the electrode 1a of the electric circuit board 1 and the electrode 2a of the second electric circuit board 2 are aligned by the same method as in the first embodiment. Next, as shown in FIG. 3C, the substrate 2 is pressed from the substrate 2 side by a heating head (not shown) as indicated by an arrow, and
The adhesive 11 is cured by heat. The pressure applied by the heating head may be applied simultaneously from the substrates 1 and 2. As a result, the electric circuit boards can be connected easily and with a high yield, and the manufacturing cost thereof can be reduced.

When a thermoplastic resin is used for the conductive particles 4, the insulating particles whose viscous flow temperature is equal to or lower than the curing temperature of the thermosetting adhesive or the viscous flow temperature of the thermoplastic adhesive are used. Is preferred. By doing so, the insulating particles can be heated and made to flow, and can be integrated with the adhesive to form a connection structure having high adhesive strength.

[0047]

According to the invention of claim 1, the impact of the pressure head at the time of crimp connection can be alleviated by the deformation of the insulating particles, and the crushed width of the conductive particles can be made appropriate.
In addition, it is possible to connect with a constant connection thickness. For this reason, unlike the conventional case, defects such as an increase in the connection resistance value due to excessive crushing of the conductive particles and a short circuit between adjacent electrodes due to the conductive member scattered due to the destruction of the conductive particles do not occur. As a result, highly reliable electrical connection can be achieved. Further, since it is possible to prevent a defect due to the impact of the pressure head, it is possible to increase the descending speed of the pressure head and shorten the connection time of the substrates.

According to the second aspect of the invention, after the impact of the pressure head at the time of crimping connection is alleviated by the deformation of the insulating particles, the pressure can be applied to the conductive particles, so that the conductive particles are properly crushed. (Elastically deformed state).
As a result, highly reliable electrical connection can be achieved. According to the invention described in claim 3, the electrodes can be reliably connected by the conductive member after connection, and a highly reliable connection structure of the electric circuit board can be obtained.

According to the fourth aspect of the present invention, the insulating particles can be sufficiently deformed to reduce the impact of the pressure head, and then the conductive particles can be connected with a proper crushing width by applying pressure. As a result, the connection thickness can be made constant, an electrical connection with a stable connection resistance value can be obtained, and a highly reliable connection structure for an electric circuit board can be obtained.

According to the fifth aspect of the invention, the conductive particles can be stably interposed between the electrodes after the connection, and the electrical connection with a stable connection resistance can be performed. As a result, a highly reliable electrical circuit board connection structure can be obtained. According to the invention described in claim 6, it is possible to suppress cracks on the substrate and the electrodes due to the insulating particles, and it is possible to obtain a highly reliable connection structure of the electric circuit substrate.

According to the seventh aspect of the invention, even when the insulating particles are broken, the connection can be made in a proper collapsed state (elastically deformed state). As a result, it is possible to obtain a highly reliable connection structure for an electric circuit board with a fixed connection thickness. According to the invention as set forth in claim 8, it is possible to remove the force of the insulating particles attempting to spread between the electrodes after the connection, and to provide a highly reliable electric circuit board in which the conductive particles and the electrodes are connected in a stable state. A connection structure can be obtained.

According to the ninth aspect of the invention, the insulating particles can be heated and flowed to be integrated with the adhesive. As a result, it is possible to obtain a connection structure for an electric circuit board having high adhesive strength. According to the invention of claim 10, the temperature dependence of the elastic modulus of the particles and the substrate can be ignored,
The types of particles and substrates that can be selected can be increased.

According to the eleventh aspect of the present invention, the electric circuit boards can be connected easily and with a high yield, and the manufacturing cost thereof can be reduced. According to the invention as set forth in claim 12, the electric circuit boards can be connected easily and with a high yield, and the manufacturing cost thereof can be reduced. If the intensity of ultraviolet rays is increased, the electric circuit board can be connected in a short time.

[Brief description of drawings]

1A and 1B are views showing a first embodiment of a connection structure and a connection method for an electric circuit board according to the present invention, in which FIG. 1A shows the connection structure and FIG. 1B shows a state before connecting the boards. Is.

FIG. 2 is a diagram showing a connection sequence of an electric circuit board according to an embodiment.

FIG. 3 is a diagram showing a second embodiment of the connection structure and the connection method for the electric circuit board according to the present invention, and is a view showing the connection sequence.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st electric circuit board 1a electrode 2 2nd electric circuit board 2a electrode 3 UV curing adhesive agent 4 Conductive particle 4a Elastic body 4b Conductive member 5 Insulating particle 11 Adhesive agent

Claims (12)

[Claims] 1. A second electrical circuit board is adhesively bonded to the second electrical circuit board.
Of the first and second electric circuit boards, in which the electric circuit boards are held and fixed, and the electrodes of the first and second electric circuit boards are electrically connected through conductive particles. 2. A connection structure for an electric circuit board, wherein insulating particles are interposed between electrodes of the electric circuit board 2. 2. The electric particle according to claim 1, wherein the particle diameter of the insulating particles before the first and second electric circuit boards are connected is equal to or larger than the particle diameter of the conductive particles. Circuit board connection structure. 3. The insulating particles are deformed after the first and second electric circuit boards are connected, and the minor axis of the particles is equal to or smaller than the particle diameter of the conductive particles before the two circuit boards are connected. The connection structure for an electric circuit board according to claim 1 or 2, wherein: 4. The connection structure for an electric circuit board according to claim 1, wherein the insulating particles are made of an elastic body, and the elastic modulus is smaller than that of the conductive particles. 5. The restoring force of the whole conductive particles after the first and second electric circuit boards are connected is larger than the restoring force of the whole insulating particles. The connection structure for an electric circuit board according to. 6. The insulating particles according to claim 1, wherein the insulating particles are made of an elastic material and have a modulus of elasticity smaller than that of the first and second electric substrates and the electrodes thereof. A connection structure for an electric circuit board as described. 7. The electric circuit according to claim 1, wherein the conductive particles are formed by using an elastic body as a core and coating the elastic body with a conductive member. Board connection structure. 8. The first and second electric circuit boards are connected to each other in a state where the conductive particles are elastically deformed and a state where the insulating particles are in a plastically deformed state or a broken state in which the elastic limit exceeds an elastic limit. A connection structure for an electric circuit board according to claim 1. 9. The connection structure for an electric circuit board according to claim 1, wherein the insulating particles are made of a thermoplastic polymer. 10. The connection structure for an electric circuit board according to claim 1, wherein the adhesive is composed of an ultraviolet curable adhesive. 11. The method of connecting an electric circuit board according to claim 1, wherein a thermosetting or thermoplastic adhesive and conductive particles are provided on the electrode terminal portion of the first electric circuit board. A step of aligning the electrodes of the first electric circuit board with the electrodes of the second electric circuit board after disposing the insulating particles, and the first electric circuit board and the second electric circuit board. A step of pressurizing with a heating head to heat cure the adhesive,
A method of connecting an electric circuit board, comprising: 12. The method for connecting an electric circuit board according to claim 1, wherein an ultraviolet curable adhesive, conductive particles, and insulating particles are arranged on the electrode terminal portion of the first electric circuit board. After the installation, the step of aligning the electrodes of the first electric circuit board with the electrodes of the second electric circuit board, and the step of pressing the first electric circuit board and the second electric circuit board with a head, And a step of irradiating the ultraviolet-curing adhesive with ultraviolet rays to cure the adhesive.