TWI763750B - Anisotropic conductive film - Google Patents

Abstract

The connection structure system of the present invention is formed by anisotropically conductively connecting the first electronic component, the second electronic component, and the third electronic component with an anisotropic conductive film, the first electronic component has a first terminal pattern, and the second electronic component has a first terminal pattern. The electronic component has a second terminal pattern having terminals different in size and pitch from the first terminal pattern, and the third electronic component has a terminal pattern corresponding to each of the first terminal pattern and the second terminal pattern. The anisotropic conductive film has at least one of the following regions: a region in which conductive particles are regularly arranged, and a plurality of regions in which at least one of the number density, particle diameter, and hardness of the conductive particles is different.

Description

Anisotropic Conductive Film

The present invention relates to an anisotropic conductive film.

In a liquid crystal display element, anisotropic conductive films are used to connect various electronic components to one substrate, for example, to connect both an IC chip and a flexible printed circuit board (FPC) to an edge of a glass substrate. In this case, an anisotropic conductive film suitable for each of a variety of electronic components is used.

On the other hand, it is proposed to connect two types of electronic components to one substrate using one sheet of anisotropic conductive film (Patent Document 1).

prior art literature

Patent Literature

Patent Document 1: Japanese Patent No. 4650050

If one sheet of anisotropic conductive film is used to connect two types of electronic components to one substrate, the number of steps or space required for connection can be reduced.

However, conventional anisotropic conductive films for connecting two types of electronic components to a single substrate are formed by randomly dispersing conductive particles in an insulating resin layer, so it is impossible to precisely define the electrical conductivity in the anisotropic conductive films. The state of dispersion of particles. Therefore, it is necessary to make the number density of the conductive particles in the anisotropic conductive film suitable for the size or the distance between the terminals of the two types of electronic parts, so that there are a large number of useless conductive particles that are not related to connection.

The present invention is aimed at solving the problems of such a conventional technique, and its subject is to make the anisotropic conductive film to connect various electronic components such as IC chips and FPCs to electronic components such as a substrate using one sheet of anisotropic conductive film. It is more suitable for various electronic parts and reduces useless conductive particles that are not related to connection.

The inventors of the present invention discovered that when the first electronic component and the second electronic component having different terminal patterns are connected to the third electronic component using one sheet of anisotropic conductive film, if the conductive particles in the anisotropic conductive film are regularly arranged , the distance between the conductive particles or the arrangement direction can be controlled, so compared with the case where the conductive particles are randomly arranged, the required amount for properly connecting both the first electronic component and the second electronic component to the third electronic component can be reduced. In addition, it is easy to improve the yield of the connection structure connected by anisotropic conductive connection, and by setting the number density, particle size, hardness, etc. of conductive particles in one anisotropic conductive film A plurality of different regions can be more suitably connected to each of the first electronic component and the second electronic component, and useless conductive particles can be further reduced, leading to the idea of the present invention.

That is, the first aspect of the present invention is a connection structure comprising anisotropically conductively connecting a first electronic component, a second electronic component, and a third electronic component using an anisotropic conductive film, the first electronic component having a first electronic component. 1 terminal pattern, the second electronic component has a second terminal pattern with terminals different in size and pitch from the first terminal pattern, the third electronic component has terminal patterns corresponding to the first terminal pattern and the second terminal pattern, respectively; and The anisotropic conductive film has at least one of the following regions: a region in which conductive particles are regularly arranged, and a plurality of regions in which at least one of the number density, particle diameter, and hardness of the conductive particles is different.

The second aspect of the present invention is an anisotropic conductive film having an insulating resin layer and conductive particles arranged in the insulating resin layer, and having a plurality of conductive particles different in at least one of number density, particle diameter and hardness area.

The third aspect of the present invention is a method for producing an anisotropic conductive film, which includes the following steps: a first pressing step of attaching conductive particles to a surface of an insulating resin layer, and pressing the conductive particles into the insulating resin layer The resin layer; and the second press-in step, in which the conductive particles are adhered to a region that is a part of the area in which the conductive particles were pressed in the first press-in step, or a region including the conductive particles in the first press-in step. The entire area or the area partially overlapping with the area where the conductive particles are pressed in the first pressing step, and the conductive particles are pressed into the insulating resin layer; and at least the number density, particle size and A plurality of regions of at least one difference in hardness.

The fourth aspect of the present invention is a method for producing a connection structure, wherein a first electronic component, a second electronic component, and a third electronic component are anisotropically conductively connected using an anisotropic conductive film, the first electronic component having a first electronic component. a terminal pattern, the second electronic component has a second terminal pattern with terminals different in size and pitch from the first terminal pattern, the third electronic component has a terminal pattern corresponding to the first terminal pattern and the second terminal pattern, respectively, and serves as a Anisotropic conductive film, using an anisotropic conductive film having at least one of the following regions: a region in which conductive particles are regularly arranged, and a plurality of conductive particles that differ in at least one of the number density, particle size, and hardness area.

The connection structure system of the present invention uses one sheet of anisotropic conductive film to perform anisotropic conductive connection between the first electronic component, the second electronic component, and the third electronic component. When an electronic component is changed to the anisotropic conductive film, the manufacturing steps can be simplified and the manufacturing can be performed at low cost. Furthermore, the connection structure system is manufactured by using "a plurality of regions having conductive particles regularly arranged, or at least one different in number density, particle diameter and hardness of conductive particles" as anisotropic conductive films, so although Manufactured using one sheet of anisotropic conductive film, this anisotropic conductive film is suitable for each of the first electronic component and the second electronic component, and useless conductive particles are reduced.

In addition, since the anisotropic conductive film of the present invention has a plurality of regions in which conductive particles are regularly arranged or in which at least one of the number density, particle diameter and hardness of conductive particles is different, these regions can be used as the first electronic component. and those corresponding to the respective terminal patterns of the second electronic component. Therefore, useless conductive particles in the anisotropic conductive film can be reduced as described above.

1‧‧‧Conductive particles

2‧‧‧Insulating resin layer

2b‧‧‧Depression (inclined)

2c‧‧‧Sag (undulation)

3‧‧‧Conductive particle dispersion layer

4‧‧‧Second insulating resin layer

10A, 10B, 10C, 10D, 10E, 10F, 10G‧‧‧Anisotropic Conductive Film

10p, 10q, 10r, 10s‧‧‧ area of anisotropic conductive film

31‧‧‧First Electronic Parts

32‧‧‧Second electronic component

33‧‧‧The third electronic component

40A‧‧‧First connection structure

40B‧‧‧Second connection structure

D‧‧‧Average particle size of conductive particles

La‧‧‧Thickness of insulating resin layer

The distance between the tangent plane of the central part of the adjacent conductive particles and the deepest part of the conductive particles

Lc‧‧‧The diameter of the exposed (directly above) part of the conductive particles in the slope or undulation

The maximum diameter of the inclination or undulation of the insulating resin layer around or directly above the Ld‧‧‧conductive particles

The maximum depth of inclination of the insulating resin layer around the conductive particles

The maximum depth of the undulations of the insulating resin layer directly above the Lf‧‧‧conductive particles

FIG. 1 is a schematic plan view of a first connection structure 40A of the present invention.

FIG. 2 is a schematic plan view of the first connection structure 40A of the present invention.

FIG. 3 is a schematic plan view of the first connection structure 40A of the present invention.

FIG. 4A is a schematic plan view of the second connection structure 40B of the present invention.

4B is a cross-sectional view of the anisotropic conductive film 10B used in the second connection structure 40B of the present invention.

4C is a cross-sectional view of the anisotropic conductive film 10B used in the second connection structure 40B of the present invention.

4D is a cross-sectional view of the anisotropic conductive film 10B used in the second connection structure 40B of the present invention.

4E is a cross-sectional view of the anisotropic conductive film 10B used in the second connection structure 40B of the present invention.

FIG. 5A is a schematic plan view of the second connection structure 40B of the present invention.

5B is a cross-sectional view of the anisotropic conductive film 10B used in the second connection structure 40B of the present invention.

5C is a cross-sectional view of the anisotropic conductive film 10B used in the second connection structure 40B of the present invention.

FIG. 6A is a schematic plan view of the second connection structure 40B of the present invention.

6B is a cross-sectional view of the anisotropic conductive film 10B used in the second connection structure 40B of the present invention.

FIG. 7 is a cross-sectional view of an anisotropic conductive film 10A used in the manufacture of the connection structure.

FIG. 8 is a cross-sectional view of an anisotropic conductive film 10A used in the manufacture of a connection structure.

FIG. 9 is a cross-sectional view of an anisotropic conductive film 10A used in the manufacture of the connection structure.

FIG. 10 is a cross-sectional view of an anisotropic conductive film 10A used in the manufacture of a connection structure.

FIG. 11 is a cross-sectional view of an anisotropic conductive film 10A used in the manufacture of a connection structure.

FIG. 12 is a cross-sectional view of an anisotropic conductive film 10A used in the manufacture of a connection structure.

FIG. 13 is a cross-sectional view of an anisotropic conductive film 10A used in the manufacture of a connection structure.

FIG. 14 is a cross-sectional view of the anisotropic conductive film 10B.

FIG. 15A is a cross-sectional view of the anisotropic conductive film 10C.

FIG. 15B is a cross-sectional view of the anisotropic conductive film 10C'.

FIG. 16 is a cross-sectional view of the anisotropic conductive film 10D.

FIG. 17 is a cross-sectional view of the anisotropic conductive film 10E.

FIG. 18 is a cross-sectional view of the anisotropic conductive film 10F of the embodiment.

FIG. 19 is a cross-sectional view of the anisotropic conductive film 10G of the embodiment.

FIG. 20 is a cross-sectional view of the anisotropic conductive film 10X for comparison.

Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code|symbol represents the same or equivalent component.

[1st connection structure]

(overall composition)

FIG. 1 is a schematic plan view of a first connection structure 40A in an aspect of the connection structure of the present invention. In this connection structure 40A, the first electronic component 31, the second electronic component 32, and the third electronic component 33 having the first terminal are anisotropically conductively connected by the anisotropic conductive film 10A. The second electronic component 32 has a second terminal pattern having terminals different in size and pitch from the first terminal pattern, and the third electronic component 33 has terminal patterns corresponding to the first terminal pattern and the second terminal pattern, respectively. In this embodiment, as the first electronic component 31 , for example, electronic components such as an IC chip and an IC module are connected, and as the second electronic component 32 , electronic components such as an FPC are connected. Moreover, as the 3rd electronic component 33 which connects these, a glass substrate, a plastic substrate, a rigid substrate, a ceramic substrate, etc. are used. In addition, in this invention, the kind of a 1st electronic component, a 2nd electronic component, and a 3rd electronic component is not specifically limited. A plurality of IC chips, IC modules, etc. may be connected as the first electronic component and the second electronic component.

In addition, in FIG. 1, the 1st electronic component 31 is connected to the 3rd electronic component 33 at one end side of the short-side direction of the anisotropic conductive film 10A, and the 2nd electronic component 32 is connected to the 3rd electronic component at the other end side 33. However, when the first electronic component 31 and the second electronic component 32 are connected to the third electronic component 33 by one sheet of the anisotropic conductive film 10A, the arrangement of these is not particularly limited. For example, as shown in FIG. 2 , the first electronic component 31 and the second electronic component 32 may be arranged in the longitudinal direction of the anisotropic conductive film 10A. Moreover, as shown in FIG. 3, the some 1st electronic component 31 may be connected to the 3rd electronic component 33, and the some 2nd electronic component 32 may be connected to the 3rd electronic component 33.

(Anisotropic conductive film in the first connection structure)

In the anisotropic conductive film 10A used for the production of the first connection structure 40A of the present invention, the conductive particles 1 are regularly arranged in the insulating resin layer 2 . Therefore, the first connection structure 40A after the anisotropic conductive connection between the first electronic component 31 and the second electronic component 32 using the anisotropic conductive film 10A also has at least a A portion of the second electronic component 32 is a region in which conductive particles are regularly arranged.

‧Regular arrangement and number density of conductive particles

Regarding the anisotropic conductive film 10A used for the production of the first connection structure 40A, a square lattice, a hexagonal lattice, a rhombic lattice, a rectangular lattice, etc. are mentioned as a regular arrangement of conductive particles. In addition, those obtained by intentionally removing part of the conductive particles forming such a lattice arrangement are also included in the lattice arrangement. The method of removing the conductive particles is not particularly limited as long as it has regularity in the longitudinal direction of the film. Moreover, as the particle arrangement|positioning of the whole electrically-conductive particle, the particle row|line|column which the electrically-conductive particle 1 is linearly arranged at a predetermined space|interval can also be juxtaposed at a predetermined space|interval. By arranging the conductive particles regularly and controlling the distance between the conductive particles or the arrangement direction, it is easy to make one of the conductive particles required to connect both the first electronic component and the second electronic component to the third electronic component. Number density optimization. Conventionally, in the anisotropic conductive film in which both the first electronic component and the second electronic component are connected to the third electronic component, since the conductive particles are randomly arranged, one of the conductive particles in the anisotropic conductive film is The number density is the same as the number density suitable for the connection of the first electronic component and the number density suitable for the connection of the second electronic component, whichever is higher. In the first connection structure 40A of the present invention, by making the conductive particles in the anisotropic conductive film regularly arranged as described above, the optimization of the number density of the conductive particles can be easily achieved, so that unnecessary waste can be reduced. conductive particles.

For example, when the first electronic component and the third electronic component are connected by COG and the second electronic component and the third electronic component are connected by FOG, the number density of the conductive particles in the anisotropic conductive film 10A can be set to less than 35,000 pieces/mm ² .

‧Area Occupancy

When specifying the number density of the conductive particles in the anisotropic conductive film 10A, the area occupancy rate calculated from the average of the number density of the conductive particles and the plan area of one conductive particle according to the following formula is used to convert the anisotropic conductive particles into It is an indicator of the thrust required for the pressing jig of the conductive film to be thermally crimped to the electronic parts.

Area occupancy rate (%)=[number density of conductive particles in plan view (item/mm ² )]×[average of the plan area of one conductive particle (mm ² /item)]×100

The area occupancy rate is preferably 35% or less, more preferably 0.3 to 30%, in terms of suppressing the thrust required for the pressing jig to be low for thermocompression bonding of the anisotropic conductive film to electronic components range.

‧Particle size of conductive particles

The particle size of the conductive particles is preferably 1 μm or more and 30 μm or less, more preferably 3 μm or more and 9 μm or less, in order to cope with the unevenness of wiring height, and to suppress the increase in on-resistance and the occurrence of short circuits. The particle size of the conductive particles before being dispersed in the insulating resin layer can be measured by a general particle size distribution analyzer. In addition, the particle diameter of the conductive particles dispersed in the insulating resin layer can also be determined using a particle size distribution analyzer. It can be image type or laser type. As an image type measuring apparatus, a wet flow type particle size/shape analyzer FPIA-3000 (Malvern Corporation) can be mentioned as an example. The number of samples (the number of conductive particles) for measuring the average particle diameter D of the conductive particles is preferably 1000 or more. The average particle diameter D of the conductive particles in the anisotropic conductive film can be determined by observation with an electron microscope such as SEM. In this case, it is preferable to set the number of samples (the number of conductive particles) for measuring the average particle diameter D of the conductive particles to 200 or more.

In addition, in the case of using those having insulating fine particles adhered to the surface thereof as conductive particles, the particle size of the conductive particles in the present invention refers to the particle size of the insulating fine particles not including the surface.

‧The ratio of the number of conductive particles that exist in non-contact

In the anisotropic conductive film 10A used for the manufacture of the first connection structure 40A, the conductive particles 1 preferably exist without contacting each other in a plan view of the film. Therefore, the number ratio of the conductive particles 1 present in non-contact with each other is 95% or more, preferably 98% or more, and more preferably 99.5% or more with respect to the entire conductive particles. As described below, when the conductive particles 1 are regularly arranged using a transfer mold, the ratio at which the conductive particles 1 are present in a non-contact manner can be easily controlled, which is preferable. When the conductive particles 1 overlapped in plan view, each was individually counted.

‧Position of conductive particles in film thickness direction

In the anisotropic conductive film 10A used for the manufacture of the first connection structure 40A, when the conductive particles 1 exist without contacting each other, the positions in the film thickness direction are preferably aligned. For example, as shown in FIG. 7 , the embedded amount Lb of the conductive particle 1 in the film thickness direction can be made uniform. Thereby, no matter between the terminal of the first electronic component 31 and the terminal of the third electronic component 33, or between the terminal of the second electronic component 32 and the terminal of the third electronic component 33, the ability to capture the conductive particles is uniform. Easy to stabilize. In addition, in the anisotropic conductive film 10A, the conductive particles 1 may be exposed from the insulating resin layer 2 or may be completely embedded.

Here, the embedded amount Lb refers to the surface of the insulating resin layer 2 in which the conductive particles 1 are embedded (the surface of the front and back surfaces of the insulating resin layer 2 where the conductive particles 1 are exposed, or the conductive particles 1 are completely embedded. In the case of the insulating resin layer 2, the distance between the tangent plane 2p of the central portion of the adjacent conductive particles and the surface of the conductive particle 1 that is closer to the distance between the adjacent conductive particles and the deepest part of the conductive particle 1.

‧Embedding rate

When the ratio of the embedded amount Lb of the conductive particles 1 to the average particle diameter D is set as the embedded ratio (Lb/D), the embedded ratio is preferably 30% or more and 105% or less. When the burying ratio (Lb/D) is 30% or more and less than 60%, the ratio of the conductive particles exposed from the relatively high-viscosity resin that maintains the conductive particles increases, so that low-pressure packaging becomes easier. When it is 60% or more, the conductive particles 1 can be easily maintained in a specific particle dispersion state or a specific arrangement by the insulating resin layer 2 . Moreover, by setting it as 105% or less, the resin amount of the insulating resin layer which functions so that the conductive particle between terminals may flow unnecessarily at the time of anisotropic conductive connection can be reduced. In addition, the conductive particles 1 may penetrate through the insulating resin layer 2, and the burying ratio (Lb/D) in this case is 100%.

In addition, the numerical value of the burying ratio (Lb/D) refers to 80% or more, preferably 90% or more, more preferably 96% or more of the total number of conductive particles contained in the anisotropic conductive film. (Lb/D) value. Therefore, the burying rate of 30% or more and 105% or less refers to 80% or more of the total number of conductive particles contained in the anisotropic conductive film, preferably 90% or more, more preferably 96% or more. 30% or more and 105% or less. By making the embedding ratio (Lb/D) of all the conductive particles uniform in this way, since the pressing load is uniformly applied to the conductive particles, the trapping state of the conductive particles in the terminal becomes good, and the conduction stability is improved.

(Insulating resin layer)

‧Viscosity of insulating resin layer

In the anisotropic conductive film 10A used for the production of the first connection structure 40A, the minimum melt viscosity of the insulating resin layer 2 is not particularly limited, and may be determined according to the use object of the anisotropic conductive film or the anisotropic conductive film The manufacturing method and the like are appropriately determined. For example, as long as the following recesses 2b ( FIG. 8 ) and 2c ( FIG. 9 ) can be formed, the amount of about 1000 Pa·s can be achieved depending on the method of manufacturing the anisotropic conductive film. On the other hand, as a method for producing an anisotropic conductive film, when conducting a method of holding conductive particles on the surface of the insulating resin layer in a specific arrangement, and pressing the conductive particles into the insulating resin layer, the insulating properties are reduced. Since the resin layer can realize film formation, it is preferable to set the minimum melt viscosity of the insulating resin layer to 1100 Pa·s or more.

In addition, as described in the following method of manufacturing an anisotropic conductive film, as shown in FIG. 8 , depressions 2 b are formed around the exposed portion of the conductive particles 1 pressed into the insulating resin layer 2 , or as shown in FIG. 9 . Generally, in terms of forming the depressions 2c directly above the conductive particles 1 pressed into the insulating resin layer 2, it is preferably 1500Pa·s or more, more preferably 2000Pa·s or more, and more preferably 3000~15000Pa·s , and more preferably 3000~10000Pa·s. As an example, the minimum melt viscosity can be obtained by using a rotational rheometer (manufactured by TA instruments), keeping it constant under a measuring pressure of 5 g, and using a measuring plate with a diameter of 8 mm. At 30 to 200° C., a temperature increase rate of 10° C./min, a measurement frequency of 10 Hz, and a load variation of 5 g with respect to the above-mentioned measurement plate were determined.

By setting the minimum melt viscosity of the insulating resin layer 2 to a high viscosity of 1500 Pa·s or more, the useless movement of the conductive particles during the crimping of the anisotropic conductive film to the article can be suppressed, especially the anisotropic conductive connection can be prevented The conductive particles that should be clamped between the terminals flow due to the resin flow.

In addition, when the conductive particle dispersion layer 3 of the anisotropic conductive film 10A is formed by pressing the conductive particles 1 into the insulating resin layer 2, the insulating resin layer 2 when the conductive particles 1 are pressed into When the conductive particles 1 are pressed into the insulating resin layer 2 so that the conductive particles 1 are exposed from the insulating resin layer 2 , the insulating resin layer 2 is formed around the conductive particles 1 as the insulating resin layer 2 is plastically deformed. A highly viscous body like the depression 2b (FIG. 8), or when the conductive particles 1 are pressed into the insulating resin layer 2 without being exposed from the insulating resin layer 2, the conductive particles 1 become the same as the conductive particles. On the surface of the insulating resin layer 2 directly above 1, a high-viscosity viscous body such as a depression 2c (FIG. 9) is formed. Therefore, the lower limit of the viscosity of the insulating resin layer 2 at 60°C is preferably 3000 Pa·s or more, more preferably 4000 Pa·s or more, and more preferably 4500 Pa·s or more, and the upper limit is preferably 20000 Pa·s or less, more preferably It is preferably 15,000 Pa·s or less, and more preferably 10,000 Pa·s or less. This measurement is performed by the same measurement method as the minimum melt viscosity, and can be obtained by extracting a value at a temperature of 60°C.

The specific viscosity of the insulating resin layer 2 when the conductive particles 1 are pressed into the insulating resin layer 2 corresponds to the shape or depth of the formed depressions 2b and 2c, and the lower limit is preferably 3000Pa·s or more, more preferably 4000Pa s or more, more preferably 4500 Pa‧s or more, and the upper limit is preferably 20000 Pa‧s or less, more preferably 15000 Pa‧s or less, and still more preferably 10000 Pa‧s or less. Moreover, it is preferable to obtain such a viscosity at 40-80 degreeC, More preferably, it is 50-60 degreeC.

As described above, by forming the depressions 2b around the conductive particles 1 exposed from the insulating resin layer 2 ( FIG. 8 ), the flattening of the conductive particles 1 generated when the article is crimped with respect to the anisotropic conductive film is self-contained. The resistance received by the insulating resin is lower than that in the case where there is no recess 2b. Therefore, the conductive particles are easily clamped by the terminals during anisotropic conductive connection, whereby the conduction performance is improved, and the trapping property is improved.

In addition, by forming depressions 2c on the surface of the insulating resin layer 2 just above the conductive particles 1 buried without being exposed from the insulating resin layer 2 ( FIG. 9 ), compared with the case where there are no depressions 2c, anisotropy The pressure when the conductive film is crimped to the article tends to be concentrated on the conductive particles 1 . Therefore, it becomes easy for the conductive particles to be pinched by the terminals at the time of anisotropic conductive connection, whereby the catchability is improved, and the conduction performance is improved.

<Instead of "slope" or "undulation" for depressions>

The "recesses" 2b and 2c of the anisotropic conductive film shown in Figs. 8 and 9 can also be described from the viewpoint of "slope" or "undulation". Hereinafter, description will be made with reference to the drawings ( FIGS. 13 to 20 ).

The anisotropic conductive film 10A is composed of the conductive particle-dispersed layer 3 ( FIG. 13 ). In the conductive particle dispersion layer 3 , the conductive particles 1 are regularly dispersed in a state of being exposed on one side of the insulating resin layer 2 . In the top view of the film, the conductive particles 1 do not contact each other, and the conductive particles 1 are regularly dispersed without overlapping each other in the film thickness direction, forming a single-layer conductive particle layer in which the positions of the conductive particles 1 in the film thickness direction are aligned.

The surface 2a of the insulating resin layer 2 around each conductive particle 1 is formed with an inclination 2b with respect to the tangent plane 2p of the insulating resin layer 2 in the central portion between adjacent conductive particles. In addition, as described below, in the anisotropic conductive film of the present invention, undulations 2c may be formed on the surface of the insulating resin layer just above the conductive particles 1 embedded in the insulating resin layer 2 ( FIG. 16 , Figure 18).

In the present invention, the term "inclined" refers to a state in which the flatness of the surface of the insulating resin layer is impaired in the vicinity of the conductive particles 1, and a part of the resin layer is chipped relative to the tangential plane 2p, and the amount of resin decreases. In other words, in the inclination, the surface of the insulating resin layer around the conductive particles is chipped with respect to the tangential plane. On the other hand, "undulation" refers to a state in which the resin is reduced by having undulations on the surface of the insulating resin layer just above the conductive particles, and there are parts having a level difference like the undulations. In other words, the resin amount of the insulating resin layer directly above the conductive particles is smaller than when the surface of the insulating resin layer directly above the conductive particles is located on the tangent plane. These can be identified by comparing the portion corresponding to the directly above the conductive particles with the flat surface portion between the conductive particles ( FIG. 16 , 2f of FIG. 18 ). In addition, there are also cases where the starting point of the undulation exists as a slope.

As described above, by forming the inclination 2b around the conductive particles 1 exposed from the insulating resin layer 2 ( FIG. 13 ), the conductive particles generated when the conductive particles 1 are sandwiched between the terminals during anisotropic conductive connection The resistance received from the insulating resin by the flattening of 1 is reduced compared with the case where there is no inclination 2b, so that it becomes easy to hold the conductive particles of the terminal, thereby improving the conduction performance and improving the catchability. The inclination is preferably along the outer shape of the conductive particles. The reason for this is that, in addition to the effect of being connected more easily, it becomes easy to recognize the conductive particles, thereby facilitating inspection and the like at the time of producing an anisotropic conductive film. In addition, some of the inclinations and undulations may disappear when the insulating resin layer is hot-pressed or the like, but the present invention includes such cases. In this case, the conductive particles may be exposed at one point on the surface of the insulating resin layer. In addition, with regard to the anisotropic conductive film, when there are various electronic components to be connected and adjustments are made according to these, it is desirable to have a high degree of freedom in design so as to satisfy various requirements. The ground disappears and can be used.

In addition, by forming the undulations 2c on the surface of the insulating resin layer 2 just above the conductive particles 1 buried without being exposed from the insulating resin layer 2 (FIG. 16, FIG. 18), as in the case of inclination, the During anisotropic conductive connection, the pressing force from the terminal is easily applied to the conductive particles. In addition, due to the undulations, the amount of resin directly above the conductive particles is reduced compared to the case where the resin is flatly stacked, so the resin directly above the conductive particles during connection is easily removed, and the terminals and the conductive particles are easy to contact, so the terminal The trapping property of the conductive particles is improved, and the conduction reliability is improved.

(Position of conductive particles in the thickness direction of the insulating resin layer)

The position of the conductive particles 1 in the thickness direction of the insulating resin layer 2 in consideration of the situation of "tilting" or "undulation" is the same as the above, and the conductive particles 1 may be exposed from the insulating resin layer 2 or may not be. It is exposed and buried in the insulating resin layer 2, and the distance from the tangent plane 2p of the central portion between the adjacent conductive particles to the deepest portion of the conductive particles (hereinafter referred to as the buried amount) Lb and the average particle size of the conductive particles The ratio of diameter to D (Lb/D) (embedding ratio) is preferably 30% or more and 105% or less.

When the burying ratio (Lb/D) is 30% or more and less than 60%, the ratio of the particles exposed from the relatively high-viscosity resin that maintains the conductive particles increases, so that low-pressure packaging becomes easier. When it is 60% or more, the conductive particles 1 can be easily maintained in a specific particle dispersion state or a specific arrangement by the insulating resin layer 2 . Moreover, by setting it as 105% or less, the resin amount of the insulating resin layer which functions so that the conductive particle between terminals may flow unnecessarily at the time of anisotropic conductive connection can be reduced.

In addition, the numerical value of the burying ratio (Lb/D) refers to 80% or more, preferably 90% or more, more preferably 96% or more of the total number of conductive particles contained in the anisotropic conductive film. (Lb/D) value. Therefore, the burying rate of 30% or more and 105% or less refers to 80% or more of the total number of conductive particles contained in the anisotropic conductive film, preferably 90% or more, more preferably 96% or more. 30% or more and 105% or less. By making the embedding ratio (Lb/D) of all the conductive particles uniform in this way, the load of pressing is evenly applied to the conductive particles, so that the trapping state of the conductive particles in the terminal is improved, and the conduction stability is improved.

The burial rate (Lb/D) can be obtained by the following method: 10 or more regions with an area of 30 mm ² or more are arbitrarily extracted from the anisotropic conductive film, and a part of the cross section of the film is observed with an SEM image and measured. A total of 50 or more conductive particles. In order to further improve the accuracy, it can also be obtained by measuring 200 or more conductive particles.

In addition, in the measurement of the burial rate (Lb/D), a certain number of objects can be obtained at one time by adjusting the focus in the surface view image. Alternatively, a laser-type discrimination displacement sensor (manufactured by KEYENCE Co., Ltd., etc.) can also be used for the measurement of the embedded rate (Lb/D).

(Embedding rate of 30% or more and less than 60%)

As a more specific embedment of the conductive particles 1 having an embedment ratio (Lb/D) of 30% or more and 60% or less, the conductive particles 1 having an anisotropic conductive film 10A shown in FIG. It is a state in which it is embedded at a 30% or more and less than 60% burying rate so as to be exposed from the insulating resin layer 2 . The anisotropic conductive film 10A has an inclination 2b, and the inclination 2b is a portion of the surface of the insulating resin layer 2 that is in contact with the conductive particles 1 exposed from the insulating resin layer 2 and the vicinity thereof with respect to the adjacent conductive particles. The tangent plane 2p of the surface 2a of the insulating resin layer in the center part is substantially along the ridgeline of the outer shape of the conductive particle.

In the case of manufacturing the anisotropic conductive film 10A by pressing the conductive particles 1 into the insulating resin layer 2 and producing the anisotropic conductive film 10A, the inclination 2b or the undulations 2c described below can be obtained by heating at 40 to 80° C. at 3000 to 20000 Pa. ‧s, more preferably formed by pressing the conductive particles 1 at 4500-15000 Pa‧s.

(Embedding rate of more than 60% and less than 100%)

As a more specific embedment of the conductive particles 1 having an embedment ratio (Lb/D) of 60% or more and 105% or less, the conductive particles 1 such as the anisotropic conductive film 10A shown in FIG. 13 can be listed first. The state where the insulating resin layer 2 is exposed is buried at a burying rate of 60% or more and less than 100%. The anisotropic conductive film 10A has an inclination 2b, and the inclination 2b is a portion of the surface of the insulating resin layer 2 that is in contact with the conductive particles 1 exposed from the insulating resin layer 2 and the vicinity thereof with respect to the adjacent conductive particles. The tangent plane 2p of the surface 2a of the insulating resin layer in the center part is substantially along the ridgeline of the outer shape of the conductive particle.

In the case where the anisotropic conductive film 10A is produced by pressing the conductive particles 1 into the insulating resin layer 2, the lower limit of the viscosity at the time of pressing the conductive particles 1 is preferably 3000Pa·s or more, more preferably 4000Pa·s or more, further preferably 4500Pa·s or more, and the upper limit is preferably 20000Pa·s or less, more preferably 15000Pa·s or less, and more preferably 10000Pa·s or less. Moreover, it is preferable to obtain such a viscosity at 40-80 degreeC, More preferably, it is 50-60 degreeC. In addition, a part of the inclination 2b or the undulations 2c may disappear due to hot pressing of the insulating resin layer, etc., the inclination 2b may be changed to the undulations 2c, or it may be embedded in the insulating resin layer having the undulations 2c. The conductive particles are exposed to the insulating resin layer 2 at one point at the top thereof.

(Embedding rate of 100%)

Next, as an aspect of the burying ratio (Lb/D) of 100% in the anisotropic conductive film of the present invention, as an anisotropic conductive film 10B shown in FIG. It has a "slope 2b that is substantially along the ridgeline of the outer shape of the conductive particles that is substantially the same as that of the anisotropic conductive film 10A shown in FIG. 13", and the exposed diameter Lc of the conductive particles 1 exposed from the insulating resin layer 2 is smaller than that of the conductive particles. For the average particle size D; like the anisotropic conductive film 10C shown in FIG. 15A, the inclination 2b around the exposed portion of the conductive particle 1 appears steeply near the conductive particle 1, and the exposed diameter Lc of the conductive particle 1 and the conductive particle The average particle size D is approximately the same; like the anisotropic conductive film 10D shown in FIG. 16, the surface of the insulating resin layer 2 has shallow undulations 2c, and the conductive particles 1 are self-insulated at one point on the top 1a The resin layer 2 is exposed.

In addition, the micro protruding portion 2q may be formed adjacent to the slope 2b of the insulating resin layer 2 around the exposed portion of the conductive particle, or the undulation 2c of the insulating resin layer just above the conductive particle. This example is shown in FIG. 15B .

Since these anisotropic conductive films 10B, 10C, 10C' and 10D have a burying rate of 100%, the tops 1a of the conductive particles 1 and the surface 2a of the insulating resin layer 2 are aligned on the same plane. When the tops 1a of the conductive particles 1 and the surface 2a of the insulating resin layer 2 are aligned on the same plane, there is an effect of being different from the case where the conductive particles 1 protrude from the insulating resin layer 2 as shown in FIG. 13 . In the case of directional conductive connection, the amount of resin in the film thickness direction is less likely to become uneven around the periphery of each conductive particle, which can reduce the movement of conductive particles caused by resin flow. In addition, even if the embedding rate is not strictly 100%, this effect can be obtained if the tops of the conductive particles 1 embedded in the insulating resin layer 2 and the surface of the insulating resin layer 2 are aligned to the same level. In other words, when the embedding ratio (Lb/D) is approximately 80-105%, especially 90-100%, it can be considered that the top of the conductive particles 1 embedded in the insulating resin layer 2 and the space between the insulating resin layer 2 The surfaces are the same, which can reduce the movement of conductive particles caused by resin flow.

Among these anisotropic conductive films 10B, 10C, 10C', and 10D, since the amount of resin around the conductive particles 1 is less likely to become uneven, 10D can eliminate the movement of the conductive particles caused by the flow of the resin. Although it is one point of the top part 1a, the conductive particles 1 are exposed from the insulating resin layer 2, so that the following effects can be expected in that the conductive particles 1 of the terminals have good trapping properties and slight movement of the conductive particles is unlikely to occur. Therefore, this aspect is particularly effective in the case of fine pitches or small gaps between bumps.

In addition, the anisotropic conductive films 10B ( FIG. 14 ), 10C ( FIG. 15A ), 10C′ ( FIG. 15B ), and 10D ( FIG. 16 ) having different shapes or depths of the inclination 2b and the undulation 2c can be changed by changing the pressure as described below. It is manufactured according to the viscosity of the insulating resin layer 2 when the conductive particles 1 are introduced.

(In the state where the burial rate exceeds 100%)

In the anisotropic conductive film of the present invention, when the burying rate exceeds 100%, the conductive particles 1 like the anisotropic conductive film 10E shown in FIG. The insulating resin layer 2 has an inclination 2b with respect to the tangent plane 2p, or the surface of the insulating resin layer 2 directly above the conductive particle 1 has a undulation 2c with respect to the tangent plane 2p (FIG. 18).

In addition, the insulating resin layer 2 around the exposed portion of the conductive particle 1 has an anisotropic conductive film 10E (FIG. 17) having a slope 2b, and the insulating resin layer 2 directly above the conductive particle 1 has a different undulation 2c. The oriented conductive film 10F ( FIG. 18 ) can be produced by changing the viscosity or the like of the insulating resin layer 2 when the conductive particles 1 are pressed into the isotropic film.

Furthermore, when the anisotropic conductive film 10E shown in FIG. 17 is used for anisotropic conductive connection, since the conductive particles 1 are directly pressed by the terminals, the ability to capture the conductive particles in the terminals is improved. In addition, when the anisotropic conductive film 10F shown in FIG. 18 is used for anisotropic conductive connection, the conductive particles 1 do not directly press the terminal, but press through the insulating resin layer 2, but exist in the pressing direction 20 (that is, the conductive particles 1 are embedded at a rate of over 100%, the conductive particles 1 are not exposed from the insulating resin layer 2, and the surface of the insulating resin layer 2 is flat ), the pressing force is easily applied to the conductive particles, and the conductive particles 1 between the terminals can be prevented from moving unnecessarily due to resin flow during anisotropic conductive connection.

The inclination 2b of the insulating resin layer 2 around the exposed portion of the conductive particles (FIG. 13, FIG. 14, FIG. 15A, FIG. 15B, and FIG. 17) or the undulation of the insulating resin layer just above the conductive particles can be easily exerted. In terms of the effect of 2c (FIG. 16, FIG. 18), the ratio (Le/D) of the maximum depth Le of the inclination 2b to the average particle diameter D of the conductive particles 1 is preferably less than 50%, more preferably less than 50%. 30%, more preferably 20~25%, the ratio (Ld/D) of the maximum diameter Ld of the inclination 2b or the undulation 2c to the average particle diameter D of the conductive particle 1 is preferably more than 100%, more preferably 100~150 %, the ratio (Lf/D) of the maximum depth Lf of the undulations 2c to the particle size D of the conductive particles 1 is greater than 0, preferably less than 10%, more preferably less than 5%.

In addition, the diameter Lc of the exposed (directly above) portion of the conductive particle 1 in the slope 2b or the undulation 2c can be set to be equal to or less than the average particle diameter D of the conductive particle 1, preferably 10-90% of the average particle diameter D. One point of the top of the conductive particles 1 may be exposed, or the conductive particles 1 may be completely buried in the insulating resin layer 2 so that the diameter Lc becomes zero.

In addition, as shown in FIG. 19 , in the anisotropic conductive film 10G having a burying ratio (Lb/D) of less than 60%, the conductive particles 1 are easily rotated on the insulating resin layer 2, so that the anisotropic conductivity is improved. In terms of the capture rate at the time of connection, it is preferable to set the burying rate (Lb/D) to 60% or more.

In addition, in the state where the burying ratio (Lb/D) exceeds 100%, when the surface of the insulating resin layer 2 is flat like the anisotropic conductive film 10X of the comparative example shown in FIG. The amount of resin between the conductive particle 1 and the terminal becomes excessive. In addition, since the conductive particles 1 do not directly contact the terminals and press the terminals, but press the terminals through the insulating resin, the conductive particles also tend to flow due to the resin flow.

In the present invention, the existence of the inclination 2b and the undulation 2c on the surface of the insulating resin layer 2 can be confirmed by observing the cross section of the anisotropic conductive film with a scanning electron microscope, and can also be confirmed by observing the surface field of view. . The inclination 2b and the undulation 2c can also be observed with an optical microscope or a metal microscope. In addition, the magnitude of the inclination 2b and the waviness 2c can also be confirmed by adjusting the focus during image observation or the like. The same is true even after the inclination and undulation are reduced by the hot pressing as described above. The reason for this is that sometimes traces remain.

(Composition of insulating resin layer)

The insulating resin layer 2 may be formed of a curable resin composition, for example, a thermopolymerizable composition containing a thermopolymerizable compound and a thermopolymerization initiator. The thermally polymerizable composition may also contain a photopolymerization initiator if necessary.

When a thermal polymerization initiator and a photopolymerization initiator are used in combination, those that function as a thermally polymerizable compound and also function as a photopolymerizable compound may be used, and in addition to the thermally polymerizable compound, the Photopolymerizable compounds. It is preferable to contain a photopolymerizable compound in addition to a thermopolymerizable compound. For example, a thermal cationic polymerization initiator is used as the thermal polymerization initiator, an epoxy compound is used as the thermal polymerizable compound, a photoradical polymerization initiator is used as the photopolymerization initiator, and an acrylate compound is used as the photopolymerizable compound .

As a photopolymerization initiator, a plurality of types that react with light having different wavelengths may be contained. Thereby, the wavelength used for photohardening of the resin constituting the insulating resin layer during the production of the anisotropic conductive film and the photohardening of the resin for bonding electronic parts to each other during the anisotropic conductive connection can be used separately.

In the photocuring at the time of manufacturing an anisotropic conductive film, all or a part of the photopolymerizable compound contained in the insulating resin layer can be photocured. By this photocuring, the arrangement of the conductive particles 1 in the insulating resin layer 2 can be maintained or immobilized, and the suppression of short circuits and the improvement of trapping properties can be expected. In addition, the viscosity of the insulating resin layer in the manufacturing process of the anisotropic conductive film can be appropriately adjusted by the photocuring. In particular, the photohardening is preferably performed when the ratio (La/D) of the layer thickness La of the insulating resin layer 2 to the average particle diameter D of the conductive particles 1 is less than 0.6. The reason for this is that when the layer thickness of the insulating resin layer 2 is relatively thin with respect to the average particle diameter of the conductive particles, the arrangement of the conductive particles is more reliably maintained or fixed in the insulating resin layer 2, and The viscosity of the insulating resin layer 2 is adjusted to suppress the decrease in yield in the connection of electronic components using the anisotropic conductive film.

The blending amount of the photopolymerizable compound in the insulating resin layer is preferably 30% by mass or less, more preferably 10% by mass or less, and still more preferably less than 2% by mass. The reason for this is that when there are too many photopolymerizable compounds, the thrust applied by pressing at the time of connection increases.

Examples of the thermally polymerizable composition include: a thermally polymerizable acrylate-based composition containing a (meth)acrylate compound and a thermal radical polymerization initiator, a thermally polymerizable acrylate-based composition containing an epoxy compound and a thermal cationic polymerization initiator Thermal cationic polymerizable epoxy-based composition of the agent, etc. In place of the thermally cationically polymerizable epoxy-based composition containing a thermally cationic polymerization initiator, a thermally anionic polymerizable epoxy-based composition containing a thermally anionic polymerization initiator may also be used. Moreover, as long as there is no particular hindrance, a plurality of polymerizable compounds may be used in combination. As an example of combined use, the combined use of a cationically polymerizable compound and a radically polymerizable compound, etc. are mentioned.

Here, as the (meth)acrylate compound, a conventionally known thermally polymerizable (meth)acrylate monomer can be used. For example, a monofunctional (meth)acrylate-based monomer and a polyfunctional (meth)acrylate-based monomer having a difunctional or higher level can be used.

As a thermal radical polymerization initiator, an organic peroxide, an azo type compound, etc. are mentioned, for example. In particular, organic peroxides which do not generate nitrogen gas which causes bubbles can be preferably used.

The usage-amount of the thermal radical polymerization initiator is preferably 2 to 60 parts by mass with respect to 100 parts by mass of the (meth)acrylate compound, since too little will lead to poor curing, and if too much, the life of the product will be shortened. , more preferably 5 to 40 parts by mass.

Examples of the epoxy compound include bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin, modified epoxy resins thereof, alicyclic epoxy resins, and the like. Two or more of these are used in combination. Moreover, you may use together an oxetane compound other than an epoxy compound.

As the thermal cationic polymerization initiator, known thermal cationic polymerization initiators for epoxy compounds can be used, for example, iodonium salts, periconium salts, phosphonium salts, ferrocenes, etc., which generate acids by heat, can be used, especially Aromatic permanium salts showing good latency to temperature can be preferably used.

Regarding the usage amount of the thermal cationic polymerization initiator, if it is too small, the curing tends to be poor, and if it is too large, the product life tends to be shortened. Therefore, it is preferably 2 to 60 parts by mass relative to 100 parts by mass of the epoxy compound. , more preferably 5 to 40 parts by mass.

The thermally polymerizable composition preferably contains a film-forming resin or a silane coupling agent. Examples of film-forming resins include phenoxy resins, epoxy resins, unsaturated polyester resins, saturated polyester resins, urethane resins, butadiene resins, polyimide resins, polyamide resins, and polyolefins. Resins and the like can be used in combination of two or more of these. Among these, a phenoxy resin can be preferably used from the viewpoints of film formability, workability, and connection reliability. The weight average molecular weight is preferably 10,000 or more. Moreover, as a silane coupling agent, an epoxy-type silane coupling agent, an acryl-type silane coupling agent, etc. are mentioned. These silane coupling agents are mainly alkoxysilane derivatives.

The thermopolymerizable composition may contain insulating conductive particles in addition to the conductive particles 1 described above in order to adjust the melt viscosity. It can be exemplified by silica powder, alumina powder, and the like. The insulating conductive particles are preferably fine conductive particles having a particle diameter of 20 to 1000 nm, and the blending amount is preferably 5 to 50 parts by mass relative to 100 parts by mass of a thermopolymerizable compound (photopolymerizable compound) such as an epoxy compound. parts by mass.

The anisotropic conductive film of the present invention may contain, in addition to the above-described insulating conductive particles, fillers, softeners, accelerators, antiaging agents, colorants (pigments, dyes), organic solvents, ion scavengers, and the like .

(layer thickness of insulating resin layer)

In the anisotropic conductive film 10A used for the production of the first connection structure 40A, the thickness of the insulating resin layer 2 is determined by the average particle diameter D of the conductive particles 1 or the first electronic component 31, the second electronic component 32, and the terminal height of the third electronic component 33 is not particularly limited. As an example, when the average particle size D is less than 10 μm, it is preferable to set the layer thickness La of the insulating resin layer 2 and the conductive particles 1 to 10 μm. The ratio (La/D) of the average particle diameter D is 0.3 or more and 10 or less, more preferably 3 or less, and still more preferably 1 or less. From the viewpoint of maintaining the arrangement of the conductive particles 1 in the insulating resin layer 2, the ratio (La/D) is more preferably 0.4 or more. Moreover, it is more preferable to set it as 1 or less from the point of suppressing the excess resin flow at the time of anisotropic conductive connection and realizing a low pressure structure. Furthermore, the ratio (La/D) is preferably less than 1, more preferably less than 1, from the viewpoint of easily exposing the conductive particles 1 from the insulating resin layer 2 and facilitating low-voltage packaging. 0.6, more preferably 0.5 or less. In addition, when the ratio (La/D) is set to 3 or less, it may be preferable to provide the second insulating resin layer 4 having a lower minimum melt viscosity than the insulating resin layer 2 .

On the other hand, when the average particle diameter D is 10 μm or more, the upper limit of La/D is 3.5 or less, preferably 2.5 or less, more preferably 2 or less, and the lower limit is 0.8 or more, preferably Preferably it is 1 or more, More preferably, it is more than 1.3.

In addition, regardless of the size of the average particle diameter D, if the layer thickness La of the insulating resin layer 2 is too large and the ratio (La/D) becomes too large, the conductive particles 1 are difficult to press against the terminals during anisotropic conductive connection. And the conductive particles easily flow due to the resin flow. Therefore, the positional displacement of the conductive particles is likely to occur, and the captureability of the conductive particles in the terminal is lowered. In addition, in order to press the conductive particles against the terminals, the thrust required to press the jig also increases, which hinders low-voltage assembly. Conversely, if the layer thickness La of the insulating resin layer 2 is too small and the ratio becomes too small, it becomes difficult to maintain the conductive particles 1 at a specific position by the insulating resin layer 2 .

(Second insulating resin layer)

In the anisotropic conductive film 10A, a second insulating resin layer 4 having a lower minimum melt viscosity than the insulating resin layer 2 may be laminated on the insulating resin layer 2 ( FIGS. 10 to 12 ). The second insulating resin layer 4 can fill the space formed by terminals such as bumps of electronic components during anisotropic conductive connection, thereby improving the adhesion between the opposing electronic components. That is, in order to realize low-voltage packaging of electronic components using the anisotropic conductive film, and to suppress the flow of resin in the insulating resin layer 2 during anisotropic conductive connection to improve the particle trapping properties of the conductive particles 1, it is desirable to increase the The viscosity of the insulating resin layer 2 is reduced, and the thickness of the insulating resin layer 2 is reduced within the range where the positional displacement of the conductive particles 1 does not occur, but if the thickness of the insulating resin layer 2 becomes too thin, it will cause the opposite The amount of resin for bonding the electronic parts to each other is insufficient, so there is a possibility that the adhesiveness may be lowered. On the other hand, by providing the second insulating resin layer 4 with a lower viscosity than the insulating resin layer 2 during the anisotropic conductive connection, the adhesiveness of the electronic components can also be improved. Due to the flow of the second insulating resin layer 4 It has high performance, so it is not easy to hinder the clamping or pressing of the conductive particles using the terminals.

In the case of laminating the second insulating resin layer 4 on the conductive particle dispersion layer 3, it is preferable to stick the second insulating resin layer 4 on the surface of the depression 2b regardless of whether the second insulating resin layer 4 is located on the surface where the depressions 2b are formed. An electronic component pressurized with a tool (the insulating resin layer 2 is attached to the electronic component placed on the stage). Thereby, useless movement of the conductive particles can be avoided, and capture performance can be improved.

The greater the difference in the minimum melt viscosity ratio between the insulating resin layer 2 and the second insulating resin layer 4, the easier it is for the spaces formed by the electrodes or bumps of electronic components to be filled with the second insulating resin layer 4, and the higher the electron density is. Adhesion of parts to each other. In addition, the more this difference is present, the less the amount of movement of the insulating resin existing in the conductive particle dispersion layer 3 is relatively small, and the conductive particles 1 between the terminals are less likely to flow due to the resin flow, whereby the conductive particles of the terminals can be trapped. increase, so it is better. In practical application, the minimum melt viscosity of the insulating resin layer 2 and the second insulating resin layer 4 is preferably 2 or more, more preferably 5 or more, and still more preferably 8 or more. On the other hand, if the ratio is too large, when the long anisotropic conductive film is made into a roll, there is a risk of resin overflow or sticking, so in practice, it is preferably 15 or less. More specifically, the preferred minimum melt viscosity of the second insulating resin layer 4 satisfies the above ratio, and is 3000 Pa·s or less, more preferably 2000 Pa·s or less, and still more preferably 100 to 2000 Pa·s.

In addition, the second insulating resin layer 4 can be formed by adjusting the viscosity in the same resin composition as the insulating resin layer 2 .

In addition, the layer thickness of the second insulating resin layer 4 is preferably 4 to 20 μm. Alternatively, it is preferably 1 to 8 times the diameter of the conductive particles, specifically, the average particle diameter thereof.

In addition, the minimum melt viscosity of the entire anisotropic conductive film formed by combining the insulating resin layer 2 and the second insulating resin layer 4 is practically 8000 Pa·s or less, preferably 200-7000 Pa·s, especially The optimum is 200~4000Pa·s.

As a specific lamination state of the second insulating resin layer 4 , for example, as shown in FIG. 10 , the second insulating resin layer 4 can be layered on a single area of the conductive particle dispersion layer 3 . In this case, the relationship between the average particle diameter D of the conductive particles 1 and the layer thickness La of the insulating resin layer 2 can be made La/D to be 0.3 or more and 10 or less as described above.

As shown in FIG. 11 , when the conductive particles 1 protrude from one side of the insulating resin layer 2 , the second insulating resin layer 4 may be layered on the protruding area so that the conductive particles 1 are submerged in the second insulating resin layer 4 . Resin layer 4. When the embedding ratio of the conductive particles 1 is 0.95 or less, it is preferable to laminate the second insulating resin layer 4 in this way, and when it is 0.9 or less, it is more preferable to laminate in this way.

As shown in FIG. 12, the 2nd insulating resin layer 4 may be laminated|stacked on "the surface on the opposite side to the surface of the insulating resin layer 2 in which the conductive particle 1 is embedded".

(third insulating resin layer)

A third insulating resin layer may be provided on the opposite side to the second insulating resin layer 4 with the insulating resin layer 2 interposed therebetween. The third insulating resin layer can function as an adhesive layer. Similar to the second insulating resin layer 4 , it may be provided to fill spaces formed by electrodes or bumps of electronic components.

The resin composition, viscosity and thickness of the third insulating resin layer may be the same as or different from those of the second insulating resin layer. The minimum melt viscosity of the anisotropic conductive film obtained by combining the insulating resin layer 2, the second insulating resin layer 4, and the third insulating resin layer is not particularly limited, and can be set to 200 to 4000 Pa·s.

(Manufacturing method of the anisotropic conductive film 10A)

As a method of manufacturing the anisotropic conductive film 10A, for example, the conductive particles 1 are held on the surface of the insulating resin layer 2 in a specific regular arrangement, and the conductive particles 1 are pressed into the insulating resin layer 2 by a flat plate or a roller.

Here, the embedding amount Lb of the conductive particles 1 in the insulating resin layer 2 can be adjusted by the pressing force, temperature, etc. when the conductive particles 1 are pressed, and the presence or absence, shape and depth of the recesses 2b and 2c can be adjusted by It is adjusted by the viscosity of the insulating resin layer 2 at the time of pressing, the pressing speed, the temperature, and the like.

In addition, it does not specifically limit as a method of holding the conductive particle 1 in the insulating resin layer 2, For example, the conductive particle 1 is held in the insulating resin layer 2 using a transfer mold. As the transfer mold, for example, a transfer mold material of inorganic materials such as silicon, various ceramics, glass, and metals such as stainless steel, or organic materials such as various resins can be used by a known method for forming openings such as photolithography. An opening is formed. In addition, the transfer mold may take a shape such as a plate shape, a roll shape, or the like.

In order to economically connect electronic components using the anisotropic conductive film, the anisotropic conductive film is preferably elongated to some extent. Therefore, the length of the anisotropic conductive film is preferably 5 m or more, more preferably 10 m or more, and still more preferably 25 m or more. On the other hand, if the anisotropic conductive film is made too long, "a conventional connection device used in the case of manufacturing electronic components using the anisotropic conductive film" cannot be used, and the workability is also poor. Therefore, the length of the anisotropic conductive film is preferably 5000 m or less, more preferably 1000 m or less, and still more preferably 500 m or less. From the viewpoint of excellent workability, it is preferable to use such a long body of an anisotropic conductive film as a roll body wound into a core.

(Manufacturing method of the first connecting structure)

As a method of manufacturing the first connection structure 40A, when the anisotropic conductive film 10A is composed of a single layer of the conductive particle-dispersed layer 3, the third electronic component 33 for various substrates and the like can be manufactured as follows: , temporarily attach and temporarily crimp the surface of the anisotropic conductive film from the side where the conductive particles 1 are embedded, and place an IC chip, etc. The first electronic components 31 are aligned and thermocompression-bonded, and the second electronic components 32 such as FPC are aligned and thermocompression-bonded. In this case, the first electronic component 31 and the second electronic component 32 can be simultaneously crimped from the side of the first electronic component 31 and the second electronic component 32 with a pressing tool, or they can be respectively pressed with a pressing tool. crimp.

In addition, the insulating resin layer of the anisotropic conductive film contains not only a thermal polymerization initiator and a thermal polymerizable compound, but also a photopolymerization initiator and a photopolymerizable compound (which may be the same as the thermal polymerizable compound) In this case, light and heat can also be used together to replace the crimping method of thermocompression. Thereby, useless movement of the conductive particles can be suppressed to a minimum. In addition, the side where the conductive particles are not embedded may be temporarily attached to the third electronic component 33 and used. Instead of the third electronic component, the anisotropic conductive film may be temporarily attached to the first electronic component and the second electronic component.

In addition, when the anisotropic conductive film 10A is formed of a laminate of the conductive particle-dispersed layer 3 and the second insulating resin layer 4, the conductive particle-dispersed layer 3 is temporarily attached to the third electronic components 33 such as various substrates Temporary crimping is performed, and the first electronic component 31 such as an IC chip or the second electronic component 32 such as an FPC is placed on the side of the second insulating resin layer 4 of the anisotropic conductive film that has been temporarily crimped. thermocompression. The second insulating resin layer 4 side of the anisotropic conductive film 10A may be temporarily attached to the first electronic component 31 or the second electronic component 32 . In addition, the conductive particle-dispersed layer 3 side may be temporarily attached to the first electronic component 31 or the second electronic component 32 and used.

[Second connection structure]

(overall composition)

4A is a schematic plan view of the second connecting structure 40B in the form of the connecting structure of the present invention, and FIGS. 4B , 4C, 4D and 4E are the anisotropic conductive film portions of the second connecting structure 40B An example of a schematic cross-sectional view. In the second connection structure 40B, the first electronic component 31 having the first terminal pattern and the second terminal pattern having the terminal size and pitch different from those of the first terminal pattern are connected by the anisotropic conductive film 10B. The electronic component 32 is anisotropically conductively connected to the "third electronic component 33 having a terminal pattern corresponding to each of the first terminal pattern and the second terminal pattern", and the second connection structure 40B is different in the following respects The first connection structure 40A, that is, a plurality of regions 10p and 10q having at least one difference in the number density, particle size, and hardness of conductive particles, is used as the anisotropic conduction used in the manufacture of the second connection structure 40B. Membrane 10B. Thereby, the connection more suitable than the 1st connection structure 40A can be performed with respect to the 1st electronic component 31 and the 2nd electronic component 32, respectively, and useless conductive particles can be further reduced.

The second connection structure 40B is also connected to the first electronic component 31 or the second electronic component 32 of the third electronic component 33 in the same manner as in FIGS. 2 and 3 illustrated in the first connection structure 40A. The number or arrangement is not particularly limited.

In the second connection structure 40B, the regions 10p and 10q in which at least one of the number density, particle diameter and hardness of the conductive particles of the anisotropic conductive film 10B are different may be adjacent to each other as shown in FIG. As shown in FIG. 5A , the region 10p and the region 10q are arranged across the region 10r in which the conductive particles do not exist. FIGS. 5B and 5C are examples of schematic cross-sectional views of the anisotropic conductive film portion of the second connection structure 40B shown in FIG. 5A . As shown in FIG. 6A , the region 10p and the region 10q may also be arranged across the region 10s in which the number density of conductive particles is higher than these. FIG. 6B is an example of a schematic cross-sectional view of the anisotropic conductive film portion of the second connection structure 40B shown in FIG. 6A . In addition, a plurality of regions different in at least one of the number density, particle size, and hardness of the conductive particles may be arranged in the short-side direction of the film as shown in FIG. 4A and the like, or may be arranged in the long-side direction. In this case, the anisotropic conductive film preferably has a region where the positions of the conductive particles in the thickness direction of the insulating resin layer are aligned on one surface or the vicinity of the insulating resin layer, and a region where the positions of the conductive particles are aligned on or near one surface of the insulating resin layer and another surface or an area near the two where the two are aligned.

(Anisotropic conductive film of the second connection structure)

As a more specific configuration of the anisotropic conductive film 10B used in the manufacture of the second connection structure, for example, when the first electronic component 31 and the third electronic component 33 are COG-connected, the anisotropic conductive film In the region 10p of 10B, the number density of the conductive particles is set to 7000 pieces/mm ² or more and 35,000 pieces/mm ² or less, or the particle size of the conductive particles is set to 2 μm or more and 9 μm or less, or the hardness of the conductive particles, The 20% compressive elastic modulus (20% K value) is set to 4000 N/mm ² or more and 28000 N/mm ² or less, preferably 4000 N/mm ² or more and 20000 N/mm ² or less. On the other hand, when the second electronic component 32 and the third electronic component 33 are FOG-connected, the number density of conductive particles is set to 50 particles/mm ² or more in the region 10q of the anisotropic conductive film 10B and 10,000 pieces/mm ² or less, or the particle size of the conductive particles is set to 2 μm or more and 30 μm or less, or the hardness of the conductive particles, the 20% compressive elastic modulus (20% K value) is set to 2000 N/mm ² or more and 18000N/ ^mm2 or less.

In addition, in the above, the various numerical values of the connection area between the first electronic component 31 and the third electronic component 33 and the connection area between the second electronic component 32 and the third electronic component 33 are repeated, but the numerical values within the above ranges are not repeated. designed to be used. For example, if the number density of the conductive particles in the region where the first electronic component 31 and the third electronic component 33 are COG-connected is 8,000 particles/mm ² , the second electronic component 32 and the third electronic component 33 are FOG-connected. The number density of the conductive particles in the region is less than 8000 particles/mm ² , and it is preferable to set a difference of 20% or more for easy identification, and it may be set to 6000 particles/mm ² or less. Other parameters are the same.

Here, as the 20% compressive elastic modulus, the compressive variable of the conductive particles when a compressive load is applied to the conductive particles using a micro-compression tester (for example, Fischerscope H-100 manufactured by Fischer) can be measured, and calculated by the following formula The K value: 20% compressive elastic modulus (K) (N/mm ² )=(3/2 ^1/2 )‧F‧S ^-3/2 ‧R ^-1/2 .

In the formula, F: the load value when the conductive particles undergo 20% compression deformation (N)

S: Compression displacement of conductive particles when 20% compression deformation occurs (mm)

R: the radius (mm) of the conductive particles.

In the region 10p and the region 10q, the number density, particle size and hardness of the conductive particles are appropriately determined according to the first electronic component 31 and the second electronic component 32 to be connected, but it is preferably determined by the number density. . The reason for this is that if the same conductive particles are used, contamination in design (unexpected mixing of other types of conductive particles) can be avoided, so it is better in terms of quality control. Therefore, the conductive particles present on at least one side preferably have the same particle size, and more preferably have the same particle size and hardness.

In addition, for example, when the number density of the conductive particles is made different in the region 10p and the region 10q, as shown in FIG. 4B , the number density of the conductive particles 1 in the vicinity of one side of the insulating resin layer 2 can be made different by making the number density of the conductive particles 1 different. As shown in FIGS. 4C , 4D and 4E to form the regions 10p and 10q, the conductive particles 1 on the front and back sides of the insulating resin layer 2 may be combined to form the regions 10p and 10p with different numbers of conductive particles. Area 10q. In this case, as shown in FIG. 4D , the conductive particles 1 on the front and back of the insulating resin layer 2 are overlapped in plan view to form conductive particle units 1u, and the conductive particle units are regularly arranged.

In the anisotropic conductive film 10B used for the manufacture of the second connection structure 40B, the configuration of the conductive particles themselves, the configuration of the insulating resin layer 2 , the configuration of the second insulating resin layer 4 , and the like can be made the same as those of the first. The anisotropic conductive film 10A used for the manufacture of the connection structure 40A is the same.

About the manufacturing method of the anisotropic conductive film 10B used for the manufacture of the 2nd connection structure 40B, it can also manufacture according to the anisotropic conductive film 10A used for the manufacture of the 1st connection structure 40A. For example, the conductive particles 1 in the formation region 10p are held on one side of the insulating resin layer 2, and the conductive particles 1 are pressed into the insulating resin layer 2 using a flat plate or a roller (first pressing step), and then the formation region is 10p, or the conductive particles 1 in the regions 10p and 10q are held on one side or the opposite side of the insulating resin layer 2 previously pressed with the conductive particles, and the conductive particles are pressed into the insulating resin layer using a flat plate or a roller (2nd pressing step). In this case, the conductive particles 1 pressed in the second pressing step may be a part of the region where the conductive particles 1 are pressed in the first pressing step in plan view ( FIG. 4C , FIG. 4D ), or The entire area including the conductive particles 1 pressed in the first pressing step ( FIG. 4E ) may partially overlap with the area where the conductive particles 1 are pressed in the first pressing step ( FIG. 6B ). Depending on the particle arrangement of the conductive particles 1 , the transfer mold for adhering the conductive particles 1 to the insulating resin layer 2 in the first press-in step may also be used to adhere the conductive particles 1 to the insulating resin layer 2 in the second press-in step. Insulating resin layer 2 (FIG. 5C). Thereby, since the manufacturing cost of an anisotropic conductive film can be reduced, it is preferable. In this case, the conductive particles 1 can be attached to one surface or the other surface of the insulating resin layer 2 .

The particle size or hardness of the conductive particles pressed in the first pressing step and the conductive particles pressed in the second pressing step may be the same or different as required. In addition, the arrangement of the conductive particles pressed in the first pressing step can be made different from the arrangement of the conductive particles pressed in the second pressing step, and the conductive particles pressed in the first pressing step can also be made different. The number density is different from the number density of the conductive particles pressed in the second pressing step.

In addition, in the case of manufacturing the anisotropic conductive film into a roll body, generally, the anisotropic conductive film with a large width is cut into a strip of a specific width to form a strip, and it is wound into a core, However, for example, for the anisotropic conductive film 10B shown in FIG. 4E , the conductive particles near the front and back sides of the insulating resin layer 2 can be uniformly formed in advance with different number densities, and the conductive particles can be cut at the positions of the dotted lines. A strip-shaped anisotropic conductive film is formed, and a region 10p and a region 10q are formed there. Thereby, the area|region 10p and the area|region 10q which differ in number density can be formed easily.

For the same reason as described above, it is preferable that the number density of the conductive particles on one side and the opposite side are different in the direction orthogonal to the longitudinal direction of the film. In addition, from the viewpoint of production, it is preferable that the number density, particle diameter, and hardness of the conductive particles on one surface and the opposite surface of the film are different. In this case, it is more preferable that the distance between the conductive particles is different between the conductive particles on one side of the film and on the opposite side.

Example

Hereinafter, the present invention will be specifically described by way of examples.

Examples 1 to 7, Comparative Examples 1 and 2

(1) Manufacture of anisotropic conductive film

With the compositions shown in Table 1, a resin composition for forming an insulating resin layer and a resin composition for forming a second insulating resin layer that form the conductive particle dispersion layer were prepared, respectively. The minimum melt viscosity of the insulating resin layer is 3000 Pa·s or more, and the ratio of the minimum melt viscosity of the insulating resin layer to the minimum melt viscosity of the second insulating resin layer is 2 or more.

The resin composition for forming the insulating resin layer (high-viscosity resin layer) was coated on a PET film with a film thickness of 50 μm using a bar coater, dried in an oven at 80° C. for 5 minutes, and then applied to the PET film. An insulating resin layer having a thickness shown in Table 2 was formed. Similarly, the 2nd insulating resin layer was formed on the PET film by the thickness shown in Table 2.

On the other hand, the conductive particles (average particle size of 3 μm or 4 μm) were arranged in a hexagonal lattice in plan view, and the number density (area density) of the conductive particles in plan view was the numerical value shown in Table 2. In addition, in Table 2, those with different areal densities of the conductive particles on the FOG side and the COG side were formed in one mold to form two regions with different areal densities. A well-known transparent resin particle is poured into the mold in a molten state, cooled and solidified, thereby forming a resin mold having a hexagonal lattice pattern of concave portions.

The concave portion of the resin mold was filled with conductive particles having an average particle size shown in Table 2 (average particle size 3 μm: AUL703 manufactured by Sekisui Chemical Industry Co., Ltd., and average particle size 4 μm: Sekisui Chemical Industry Co., Ltd. AUL704), and the insulating resin layer described above was covered thereon, and it was pressed at 60° C. at 0.5 MPa and bonded. Then, the insulating resin layer was peeled off from the mold, and the conductive particles on the insulating resin layer were pressed into the insulating resin layer under (pressing conditions: 60 to 70° C., 0.5 MPa) to form a conductive particle dispersion layer ( Embodiment 1～7).

In Comparative Examples 1 and 2, conductive particles were mixed with the resin composition forming the insulating resin layer shown in Table 1 to form a conductive particle-dispersed layer in which the conductive particles were randomly dispersed in a single layer.

Furthermore, by layering a second insulating resin layer on the surface area of the conductive particle-dispersed layer, a two-layer type anisotropic conductive film was produced (Examples 1 to 7, Comparative Examples 1 and 2)

In addition, the 20% compressive elastic modulus (20% K value) of the conductive particles used is measured using a micro-compression tester (eg, Fischerscope H-100 manufactured by Fischer Corporation). The results are shown in Table 2.

(2) Evaluation

The anisotropic conductive films of the examples and comparative examples produced in (1) were cut out to an area sufficient for the production of the following evaluation connectors, and a part of the cut anisotropic conductive films was cut out. Arranged between the IC for evaluation shown below and the glass substrate, heated and pressurized under the conditions of 180° C., 60 MPa, 5 seconds to perform anisotropic conductive connection, followed by other using the same anisotropic conductive film. The FPC for evaluation was heated and pressurized under the conditions of a tool width of 1.5 mm, 200° C., 5 MPa, and 5 seconds, and was connected to the glass substrate to obtain an IC for evaluation and an FPC for evaluation using one sheet of anisotropic conductive film. An anisotropic conductive connection to a glass substrate is a connector for evaluation.

IC for evaluation:

Outline 1.8×30mm

Thickness 0.5mm

The size of bumps is 30×85μm, the distance between bumps is 10μm, the height of bumps is 15μm, and the number of terminals is 820

FPC for evaluation:

Terminal pitch 20μm

Terminal width: gap between terminals = 1:1

Polyimide film thickness/copper foil thickness (PI/Cu)=38/8, tin plating (Sn plating)

Glass base board:

(COG side)

Glass material Corning 1737F

Electrode ITO wiring

Wiring thickness 0.5mm

(FOG side)

Electrode ITO wiring

Wiring thickness 0.7mm

About the connector for evaluation thus obtained, (a) conduction resistance, (b) conduction reliability, (c) minimum trapping number, (d) short-circuit rate were measured and evaluated as follows. The results are shown in Table 2.

(a) On-resistance

The on-resistance of the COG-side connection portion and the FOG-side connection portion of the connector for evaluation was measured by the four-terminal method. In actual use, it is preferably 2Ω or less.

(b) On reliability

The connector for evaluation was left to stand in a thermostat with a temperature of 85°C and a humidity of 85%RH for 500 hours, and the subsequent on-resistance of the COG-side connection part and the FOG-side connection part was measured in the same manner as the initial on-resistance. In actual use, it is preferably 5Ω or less.

(c) Minimum number of catches

The number of captured conductive particles was measured for 100 terminals of each of the COG-side connection portion and the FOG-side connection portion of the connector for evaluation, and the minimum captured number was obtained, and the evaluation was performed according to the following criteria. In actual use, the B evaluation or higher is preferable.

Minimum catch count evaluation standard

A: 10 or more

B: 5 or more but less than 10

C: 3 or more but less than 5

D: less than 3

(d) Short circuit rate

For each of the COG-side connection part and the FOG-side connection part of the connector for evaluation, the number of short circuits in each of them was measured by the following method, and the ratio of the measured number of short circuits to the number of terminals was obtained as the short circuit rate, based on the following criteria Evaluate. In actual use, the B evaluation or higher is preferable.

Short circuit rate of COG side connection

Using the following IC for evaluation of short-circuit rate, under the same connection conditions as above, obtain a connector for evaluation on the COG side, measure the number of shorts in the obtained connector for evaluation, and obtain the measured number of shorts relative to the number of shorts for evaluation The ratio of the number of IC terminals is used as the short circuit rate.

IC for short-circuit rate evaluation (comb-teeth TEG (test element group) with 7.5μm gap): 15×13mm

Thickness 0.5mm

Bump size 25×140μm, distance between bumps 7.5μm, bump height 15μm

Short circuit rate of FOG side connection

(a) FOG-side evaluation was obtained by connecting the same FPC to an alkali-free glass substrate (thickness 0.7 mm) under the same connection conditions as the evaluation FPC used for the preparation of the connector for evaluation of the on-resistance test. As for the connector, the number of short circuits of the obtained connector for evaluation was measured, and the short-circuit rate was determined from the number of short circuits measured and the number of gaps of the connector for evaluation.

Short circuit rate evaluation standard

A: less than 50ppm

B: 50ppm or more and less than 100ppm

C: 100ppm or more and less than 200ppm

D: 200ppm or more

According to Table 2, in Examples 4, 5, 6, and 7, the areal density, particle size, and hardness of the conductive particles did not change at the FOG-side connecting portion and the COG-side connecting portion, but the conductive particles were regularly arranged, so the conduction was conducted. Resistance, conduction reliability, number of catches, and short-circuit rate are all results that can be used in practice. In addition, in Examples 1, 2, and 3, it can be seen that the area density, particle size, and hardness of the conductive particles are different between the FOG-side connecting portion and the COG-side connecting portion, and the conduction reliability of the FOG-side or COG-side connecting portion is higher than that of the Example. 4, 5, 6, and 7 have improved. On the other hand, in Comparative Examples 1 and 2, the areal density, particle size, and hardness of the conductive particles did not change in the FOG-side connecting portion and the COG-side connecting portion, and the conductive particles were randomly dispersed, so the number density of the conductive particles was higher. In Comparative Example 1, which is high, the on-resistance and on-reliability of the FOG-side connecting portion are poor, and in Comparative Example 2, where the number density of conductive particles is low, the on-resistance and on-reliability of the COG-side connecting portion are poor.

1‧‧‧Conductive particles

2‧‧‧Insulating resin layer

10A‧‧‧Anisotropic Conductive Film

31‧‧‧First Electronic Parts

32‧‧‧Second electronic component

33‧‧‧The third electronic component

40A‧‧‧First connection structure

Claims (19)

A connection structure which anisotropically conductively connects a first electronic component, a second electronic component, and a third electronic component with an anisotropic conductive film, the first electronic component having a first terminal pattern, and the second electronic component It has a second terminal pattern whose size and pitch of terminals are different from those of the first terminal pattern, the third electronic component has terminal patterns corresponding to the first terminal pattern and the second terminal pattern, respectively, and the anisotropic conductive film has the following At least one of the regions: a region in which the conductive particles are regularly arranged, and a plurality of regions in which at least one of the number density, particle size, and hardness of the conductive particles is different, and the insulating resin layer near the conductive particles of the above-mentioned anisotropic conductive film The surface is inclined or undulated with respect to the tangent plane of the insulating resin layer in the central part between the adjacent conductive particles. In the above-mentioned inclination, the surface of the insulating resin layer near the conductive particles is defective with respect to the tangent plane. In the undulation, the resin amount of the insulating resin layer directly above the conductive particles is smaller than when the surface of the insulating resin layer directly above the conductive particles is located on the tangent plane. The connecting structure of claim 1, wherein the anisotropic conductive film has a region where conductive particles are regularly arranged and the number density of the conductive particles is less than 35,000/mm ² . The connection structure of claim 1, wherein the anisotropic conductive film has a plurality of regions where conductive particles are regularly arranged and at least one of the number density, particle diameter, and hardness of the conductive particles is different. An anisotropic conductive film, which has an insulating resin layer and conductive particles arranged in the insulating resin layer, and has a plurality of regions different in at least one of the number density, particle size and hardness of the conductive particles, and the vicinity of the conductive particles The surface of the insulating resin layer has an inclination or undulation with respect to the tangent plane of the insulating resin layer in the central part between the adjacent conductive particles, and in the above-mentioned inclination, the surface of the insulating resin layer near the conductive particles is relative to the tangent plane. Defects occur, and in the above-mentioned undulations, the resin amount of the insulating resin layer directly above the conductive particles is higher than the surface position of the insulating resin layer directly above the conductive particles. less at this tangent plane. The anisotropic conductive film of claim 4, wherein the conductive particles are regularly arranged. The anisotropic conductive film of claim 4 or 5, wherein the conductive particles are arranged in the short-side direction or the long-side direction of the anisotropic conductive film with at least one difference in number density, particle size and hardness of multiple regions. The anisotropic conductive film of claim 4 or 5 of the scope of the application, which has: a region where the positions of the conductive particles in the thickness direction of the insulating resin layer are aligned on or near a surface of the insulating resin layer; An area in which a surface or its vicinity and another surface or its vicinity are aligned. The anisotropic conductive film of claim 7 of the scope of the application has: a region in which two conductive particle units overlapping with conductive particles are regularly arranged in a plan view of the anisotropic conductive film, and a region in which separate conductive particles are regularly arranged area. The anisotropic conductive film of claim 4 or 5 of the claimed scope, wherein the insulating resin laminate layer has a second insulating resin layer having a lower minimum melt viscosity than the insulating resin layer. A method for manufacturing an anisotropic conductive film, comprising the steps of: a first pressing step of attaching conductive particles to a surface of an insulating resin layer, and pressing the conductive particles into the insulating resin layer; and a first pressing step. 2. The pressing step is to attach the conductive particles to an area that is a part of the area where the conductive particles are pressed in the first pressing step in plan view, or includes the conductive particles pressed in the first pressing step. The entire area of the conductive particles, or the area partially overlapping the area where the conductive particles are pressed in the first pressing step; the conductive particles are pressed into the insulating resin layer; and at least the number density of the conductive particles, the number of particles In a plurality of regions different in at least one of diameter and hardness, the surface of the insulating resin layer in the vicinity of the conductive particles of the anisotropic conductive film is inclined with respect to the tangent plane of the insulating resin layer in the central part between the adjacent conductive particles ups and downs, in the aforementioned inclinations, The surface of the insulating resin layer in the vicinity of the conductive particles is deficient with respect to the above-mentioned tangential plane, and the amount of resin in the insulating resin layer directly above the conductive particles is higher than the surface of the insulating resin layer directly above the conductive particles in the above-mentioned undulations. less at this tangent plane. The method for producing an anisotropic conductive film of claim 10, wherein the conductive particles pressed into the insulating resin layer in the first pressing step and the conductive particles pressed into the insulating resin layer in the second pressing step The particle size and hardness of the conductive particles are the same. The method for producing an anisotropic conductive film of claim 10, wherein the conductive particles pressed into the insulating resin layer in the first pressing step and the conductive particles pressed into the insulating resin layer in the second pressing step The conductive particles differ in particle size or hardness. The method for producing an anisotropic conductive film according to claim 10, wherein the arrangement or number density of the conductive particles pressed into the insulating resin layer in the first pressing step and the pressing in the second pressing step The arrangement and number density of the conductive particles to the insulating resin layer are different. The method for producing an anisotropic conductive film of claim 10, wherein, in the first press-in step, conductive particles are adhered to the insulating resin layer using a transfer mold, and in the second press-in step, using This transfer mold makes conductive particles adhere to the insulating resin layer. The method for producing an anisotropic conductive film according to claim 10, wherein, in the second pressing step, conductive particles are attached to the one surface or the other surface of the insulating resin layer. The method for producing an anisotropic conductive film according to any one of Claims 10 to 15, wherein the insulating resin layer into which the conductive particles are pressed is cut after the second pressing step. A method of manufacturing a connection structure, comprising anisotropic conductive connection of a first electronic component, a second electronic component, and a third electronic component using an anisotropic conductive film, the first electronic component having a first terminal pattern, the first electronic component having a first terminal pattern, and the first electronic component having a first terminal pattern. 2. The electronic component has a second terminal pattern having terminals different in size and pitch from the first terminal pattern, the third electronic component has terminal patterns corresponding to the first terminal pattern and the second terminal pattern, respectively, and, As the anisotropic conductive film, an anisotropic conductive film having at least one of the following regions is used: a region having a region in which conductive particles are regularly arranged, and at least one of the number density, particle diameter, and hardness of the conductive particles In a plurality of different regions, the surface of the insulating resin layer in the vicinity of the conductive particles of the anisotropic conductive film has an inclination or undulation with respect to the tangent plane of the insulating resin layer in the central portion between the adjacent conductive particles, and in the above inclination , the surface of the insulating resin layer near the conductive particles is defective relative to the above-mentioned tangent plane, and in the above-mentioned undulations, the resin amount of the insulating resin layer directly above the conductive particles is higher than that of the insulating resin layer directly above the conductive particles. The surface is less when it lies in this tangent plane. The method for producing a connecting structure of claim 17, wherein the first electronic component and the second electronic component mounted on the third electronic component via the anisotropic conductive film are separated from the first electronic component. The side of the component and the second electronic component is crimped with a press tool. The method for producing a connecting structure of claim 17, wherein the first electronic component and the second electronic component are simultaneously crimped.

Images