TWI750239B - Film containing filler - Google Patents

Abstract

The filler-containing film 10A such as the anisotropic conductive film of the present invention includes a resin layer 2 and a filler-dispersed layer 3, and the filler-dispersed layer 3 includes a first filler layer composed of a filler 1A dispersed in the resin layer 2 as a single layer. and a second filler layer, which is composed of the filler 1B dispersed in the resin layer 2 as a single layer at a depth different from that of the first filler layer. The filler 1A of the first filler layer is exposed from or close to one surface 2a of the resin layer 2 , and the filler 1B of the second filler layer is exposed from or close to the other surface 2b of the resin layer 2 .

Description

Films with fillers

The present invention relates to a filler-containing film such as an anisotropic conductive film.

Filler-containing films in which fillers are dispersed in resin layers are being used in a variety of applications such as matte films, capacitor films, optical films, marking films, antistatic films, and anisotropic conductive films (Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4).

As one aspect of the film containing a filler, for example, an anisotropic conductive film is widely used when mounting electronic components such as IC chips. From the viewpoint of making the anisotropic conductive film cope with a high mounting density, in the anisotropic conductive film, high-density dispersion of conductive particles in the insulating resin layer thereof is proceeding. However, when the number density of the conductive particles is increased too much, a short circuit is likely to occur in a connection structure of electronic components using an anisotropic conductive film.

In view of this, there has been proposed a method for applying a resin liquid containing conductive particles to an insulating resin layer or a release film using a coating roll having regular grooves on the surface, such as a gravure coater, when producing an anisotropic conductive film. , the conductive particles are regularly arranged in a single layer in the insulating resin layer (Patent Document 5). Furthermore, there is proposed a method of transferring the conductive particles dispersed in a specific arrangement to the first insulating resin layer and the second insulating resin layer, respectively, using a transfer mold, and transferring the first insulating resin to which the conductive particles are transferred. The layer and the second insulating resin layer are bonded together to form a first conductive particle layer and a second conductive particle layer in which conductive particles are regularly arranged at different depths of the anisotropic conductive film (Patent Document 6).

prior art literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2006-15680

Patent Document 2: Japanese Patent Laid-Open No. 2015-138904

Patent Document 3: Japanese Patent Application Laid-Open No. 2013-103368

Patent Document 4: Japanese Patent Laid-Open No. 2014-183266

Patent Document 5: Japanese Patent Laid-Open No. 2016-31888

Patent Document 6: Japanese Patent Laid-Open No. 2015-201435

According to the method for producing an anisotropic conductive film described in Patent Document 5, since the conductive particles are regularly arranged, even if the number density of the conductive particles is increased, the ease of short-circuiting is lower than when the conductive particles are randomly arranged. However, since the conductive particles are arranged in a single layer on one side of the anisotropic conductive film, there is a limit to accurately arranging the conductive particles without causing a short circuit when the number density is increased.

According to the method for producing an anisotropic conductive film described in Patent Document 6, since the conductive particles are held in each of the first insulating resin layer and the second insulating resin layer, it is possible to improve the conductivity of the conductive particles in the entire anisotropic conductive film. Number density, and suppress the generation of short circuits. However, according to the method for producing an anisotropic conductive film described here, a curable resin is used for the first insulating resin layer and the second insulating resin layer, and the conductive particles are held in these resin layers by curing , and the first insulating resin layer and the second insulating resin layer are bonded together, there is a possibility that the adhesiveness of the surface of the anisotropic conductive film will decrease, so the temporary adhesion of the anisotropic conductive film to the electronic component is performed. The workability is lowered when the anisotropic conductive film is attached or temporarily crimped to an electronic component by low-temperature crimping and fixed to the component.

In view of this, the subject of the present invention is that in a film containing a filler represented by an anisotropic conductive film, by having a first filler layer and a second filler layer at different depths, the number density of the fillers can be increased, Improve functionality (eg, for high-density installations). Specifically, when a film containing a filler is formed as an anisotropic conductive film, the problem is to suppress the occurrence of short circuits in the connection structure between electronic components and improve connection reliability, and furthermore, in order to make the anisotropic conductive film The workability in temporary attachment or temporary crimping of films containing fillers such as films is improved to make the film surface sticky.

The present inventors have found that the number density of fillers is increased by providing the first filler layer and the second filler layer at different depths of the resin layer during manufacture, and especially the anisotropy of one aspect of making a film containing fillers In the case of a conductive film, in the case of a film containing a filler that suppresses short-circuiting, if the filler is pressed into the front and back sides of the resin layer, the first filler layer is exposed from one surface of the resin layer or disposed near the surface. In addition, the second filler layer is exposed from the other surface of the resin layer or disposed near the surface, so that the conductive particles are easily captured by the terminals of the electronic parts to be connected by anisotropic conductive connection, the connection reliability is improved, and it is easy to ensure The stickiness of the film surface led to the idea of the present invention. By providing the filler on both sides in this way, it is possible to contribute to the impartation or improvement of the performance of the film containing the filler, the stability of the quality, and the reduction of the cost.

That is, the present invention provides a filler-containing film including a resin layer and a filler-dispersed layer, wherein the filler-dispersed layer includes: a first filler layer composed of a filler dispersed in the resin layer in a single layer; and a second filler layer, which is composed of a single layer of filler dispersed in the resin layer at a depth different from that of the first filler layer; and the filler of the first filler layer is exposed from one surface of the resin layer, or is close to the surface, the second The filler of the filler layer is exposed from the other surface of the resin layer, or is close to the other surface. In particular, as a preferred aspect of a film containing a filler, the present invention provides a film containing a filler, wherein the filler is conductive particles, the resin layer is an insulating resin layer, and the above-mentioned film containing the filler is used as an anisotropic film. conductive film.

In addition, the present invention provides a method for producing the film containing the above-mentioned filler, which comprises: keeping the filler on a surface of the resin layer in a specific dispersed state, pressing the filler into the resin layer, and making other fillers in a specific state. The dispersed state is maintained on the other surface of the resin layer, and the filler is pressed into the resin layer.

Furthermore, the present invention provides a film-laminated body in which the above-mentioned filler-containing film is attached to an article, and a connecting structure in which a first article and a second article are connected via the above-mentioned filler-containing film; The filler-containing film of the film is a connecting structure for anisotropically conductively connecting the first electronic component and the second electronic component. Furthermore, the present invention provides a method for producing a connected structure, which press-bonds a first article and a second article through the film containing the filler; and a method for producing a connected structure, which separates the first article and the second article. The first electronic component and the second electronic component are used as the first electronic component and the second electronic component, and the first electronic component and the second electronic component are produced by thermocompression bonding of the first electronic component and the second electronic component through a film containing a filler used as an anisotropic conductive film. A connection structure formed by anisotropic conductive connection of electronic components.

In the anisotropic conductive film according to one aspect of the filler-containing film of the present invention, since the filler is exposed from the front and back surfaces of the resin layer or exists close to the surface, when constituted as an anisotropic conductive film , the conductive particles are easily captured by the terminals of the electronic components to be anisotropically conductively connected. Therefore, the connection reliability is improved.

In addition, the number density of the first filler layer and the number density of the second filler layer are respectively lower than the number density of the filler in the entire film. Therefore, even if the filler exists in a high density in the whole film, it can avoid the possibility that the viscosity of a film surface may fall by this. Furthermore, according to the film containing the filler, such as the anisotropic conductive film of the present invention, it is not necessary to harden the resin layer in order to fix the filler to the resin layer, and thus, the adhesiveness can be ensured on the film surface. In addition to the improvement in viscosity, it is also expected that by having the filler not only on the surface of one side of the film containing the filler but on both sides, it can also be expected to impart functionality different from the case where the filler is provided only on the surface of one side.

In addition, since the number density of the first filler layer and the number density of the second filler layer are respectively lower than the number density of the fillers in the entire film, it becomes easy to precisely control the arrangement of the fillers in each filler layer Therefore, even if the arrangement spacing of fillers in the whole film containing fillers such as anisotropic conductive films is narrowed, the fillers can be precisely arranged in a specific arrangement. Therefore, combined with the above-mentioned improvement of catchability, it is also suitable for the connection of fine pitches, for example, it can be used for the connection of electronic parts with terminal widths of 6 μm to 50 μm and spacing between terminals of 6 μm to 50 μm. In addition, as long as the effective connection terminal width (the width of the overlapping part in plan view among the widths of the pair of terminals facing each other during connection) is 3 μm or more, and the shortest distance between terminals is 3 μm or more, it is possible to connect electronic devices without causing a short circuit. Components. Moreover, as another aspect, for example, there is an optical film, and the optical performance of the filler can be adjusted by adjusting the number ratio of the filler in the resin layer in the thickness direction and in a plan view without contacting and being independent. The same can be said for those directly related to appearance, such as matte films. Since it can be adjusted on both sides, it is easy to contribute to performance or quality improvement and cost reduction.

1A, 1B‧‧‧Packing

1C, 1C ₁ , 1C ₂ ‧‧‧Packing unit

2‧‧‧Resin layer

2a, 2b‧‧‧Surface of resin layer

2x‧‧‧dent

2y‧‧‧Sag

3‧‧‧Filler dispersion layer

4‧‧‧Second resin layer

10, 10A, 10B, 10C, 10D, 10E, 10F, 10G‧‧‧Films containing fillers

10Ap‧‧‧One end of film containing filler

10Aq‧‧‧The other end of the film containing the filler

20, 21‧‧‧Terminal

30‧‧‧First Electronic Parts

31‧‧‧Second electronic component

A‧‧‧Grid axis of packing arrangement

DA, DB‧‧‧Particle Size

La‧‧‧Layer Thickness of Resin Layer

L1, L2‧‧‧Embedding amount

L3‧‧‧The distance between the closest particles between the fillers in the first filler layer

L4‧‧‧The distance between the closest particles between the fillers in the second filler layer

Diameter of exposed portion of Lc‧‧‧filler

Ld‧‧‧Maximum diameter of depression (inclined)

Le‧‧‧Maximum depth of depression (inclined)

Lf‧‧‧Maximum depth of depression (undulation)

θ‧‧‧The angle formed by the longitudinal direction of the terminal and the grid axis of the arrangement of the conductive particles

1A is a plan view showing an arrangement of fillers (conductive particles) in a film containing a filler (an anisotropic conductive film of one aspect) 10A of an example.

FIG. 1B is a cross-sectional view of a filler-containing membrane 10A of an embodiment.

FIG. 2 is a cross-sectional view of a film containing a filler in which the filler of the first filler layer and the filler of the second filler layer have an embedding ratio of about 100% and the filler is exposed from the surface of the resin layer.

3 is a cross-sectional view of a filler-containing film in which the filler of the first filler layer and the filler of the second filler layer have an embedding ratio of about 100% and the filler is embedded in the resin layer so that the surface of the resin layer becomes flat.

4 is a cross-sectional view of a film containing a filler in which the filling rate of the filler is slightly more than 100% and the surface of the resin layer directly above the filler has depressions.

5A is a plan view showing an arrangement of fillers (conductive particles) in a film containing a filler (an anisotropic conductive film of one aspect) 10B of an example.

FIG. 5B is a cross-sectional view of the filler-containing membrane 10B of the embodiment.

FIG. 6 is a cross-sectional view of an anisotropic conductive connection of electronic components using the filler-containing film 10A.

7A is a plan view showing an arrangement of fillers (conductive particles) in a film containing a filler (anisotropic conductive film of one aspect) 10C of an example.

FIG. 7B is a cross-sectional view of the filler-containing membrane 10C of the embodiment.

8A is a plan view showing an arrangement of fillers (conductive particles) in a film containing a filler (an anisotropic conductive film of one aspect) 10D of an example.

FIG. 8B is a cross-sectional view of the filler-containing membrane 10D of the embodiment.

FIG. 9 is a plan view showing the arrangement of the packing unit 1C before and after the anisotropic conductive connection.

FIG. 10 is a cross-sectional view of a connecting structure in which electronic components are anisotropically conductively connected using a film 10D containing a filler.

11A is a cross-sectional view of a filler-containing film having a second resin layer (an anisotropic conductive film of one embodiment thereof) 10E.

11B is a cross-sectional view of a filler-containing film having a second resin layer (anisotropic conductive film of one aspect thereof) 10F.

11C is a cross-sectional view of 10G of a filler-containing film (an anisotropic conductive film of one aspect thereof) having a second resin layer.

FIG. 12 is a process explanatory diagram of the manufacturing method of the filler-containing film (anisotropic conductive film of its one form) 10 which has a 2nd resin layer.

Hereinafter, the film containing the filler of the present invention will be described in detail with reference to the drawings, mainly as an anisotropic conductive film in one aspect. In addition, in each figure, the same code|symbol represents the same or equivalent component.

<Overall composition of film containing filler>

1A is a plan view illustrating a filler arrangement of a film 10A containing a filler according to an embodiment of the present invention, and FIG. 1B is an X-X cross-sectional view thereof.

The filler-containing film 10A is composed of a resin layer 2 and a filler-dispersed layer 3. The filler-dispersed layer 3 is composed of a first filler layer and a second filler layer. The first filler layer is formed from a surface 2a of the resin layer 2 on the surface. The film thickness direction is composed of filler 1A monolayer dispersed at a specific depth, and the second filler layer is composed of filler 1B monolayer dispersed at a depth different from that of the first filler layer. The filler 1A of the first filler layer is segregated on the side of one surface 2a of the resin layer 2 and is exposed from the surface 2a, and the filler 1B of the second filler layer is segregated on the side of the other surface 2b of the resin layer 2 and is exposed from the surface 2a. This surface 2b is exposed. In addition, in the figure, the filler 1A of the first filler layer is shown as dark, and the filler 1B of the second filler layer is shown as white.

Furthermore, the dispersion state of the filler of the present invention includes the state in which the fillers 1A and 1B are randomly dispersed and the state in which the fillers are dispersed in a regular arrangement unless otherwise specified.

In addition, in the film 10A containing the filler of this embodiment, one of the number density of the filler 1A in the first filler layer and the number density of the filler 1B in the second filler layer gradually increases in the longitudinal direction of the film, and the other is One is gradually reduced, and the number density of fillers 1A and 1B in total in the first filler layer and the second filler layer is excellent in uniformity in the entire film.

<filler>

Fillers 1A and 1B can be selected from known inorganic fillers (metals, metal oxides, metal nitrides, etc.), organic fillers (resin particles, rubber particles, etc.), organic materials mixed with inorganic fillers, etc., according to the application of the film containing the filler. Fillers of materials (for example, particles whose centers are formed of resin materials and whose surfaces are plated with metal (metal-coated resin particles), those formed by attaching insulating fine particles to the surfaces of conductive particles, and those formed by insulating the surfaces of conductive particles It is appropriately selected according to the properties required by the application such as hardness and optical properties. For example, in optical films or matte films, silica fillers, titanium oxide fillers, styrene fillers, acrylic fillers, melamine fillers, various titanates and the like can be used. In the film for capacitors, titanium oxide, magnesium titanate, zinc titanate, bismuth titanate, lanthanum oxide, calcium titanate, strontium titanate, barium titanate, barium titanate zirconate, lead titanate zirconate, and the like can be used. etc. mixture. The following film may contain polymer-based rubber particles, polysiloxane rubber particles, and the like. The anisotropic conductive film may contain conductive particles. Examples of the conductive particles include metal particles such as nickel, cobalt, silver, copper, gold, and palladium, alloy particles such as solder, metal-coated resin particles, and metal-coated resin particles having insulating fine particles adhered to the surface. You may use 2 or more types together. Among them, metal-coated resin particles are preferred in terms of easily maintaining contact with the terminal due to the rebound of the resin particles after connection and stable conduction performance. In addition, the surface of the conductive particles may be subjected to an insulating treatment that does not impede the conduction characteristics by a known technique. The above-mentioned fillers listed by application are not limited to this application, and films containing fillers for other applications may also be included as needed. Moreover, in the film containing a filler for each application, two or more types of fillers may be used in combination as necessary.

The shape of the filler can be appropriately selected from spherical, ellipsoidal, columnar, needle-like, a combination of these, and the like according to the application of the film containing the filler. The spherical shape is preferable in that it is easy to confirm the arrangement of the fillers and to maintain a uniform state. In particular, when the film containing the filler is constituted as an anisotropic conductive film, it is preferable that the conductive particles as the filler be substantially spherical. By using substantially true spheres as conductive particles, for example, as described in Japanese Patent Laid-Open No. 2014-60150, when a transfer mold is used to manufacture an anisotropic conductive film in which conductive particles are arranged, the conductive particles are smoothly deposited on the transfer mold. By rolling, the conductive particles can be filled in specific positions on the transfer mold with high precision. Therefore, the conductive particles can be precisely arranged.

The particle diameters DA and DB of the fillers 1A and 1B are preferably 1 μm or more and 30 μm or less, more preferably 3 μm or more and 9 μm in order to cope with the unevenness of the wiring height, and in order to suppress the increase in the on-resistance and the occurrence of short circuits. the following.

The particle size of the filler 1A of the first filler layer and the particle size of the filler 1B of the second filler layer may be the same or different. When the film containing the filler is constituted as an anisotropic conductive film, the flatness after the anisotropic conductive connection of the conductive particles 1A and 1B is compressed, especially when the conductive particles are metal. In the case of covering the resin particles, it is preferable to set the same compression state to stabilize the conduction performance. In addition, the material and hardness (for example, compressive elastic modulus, etc.) of the filler 1A and the filler 1B may be the same or different.

In addition, the particle diameters of fillers 1A and 1B can be measured by a general particle size distribution measuring device, and the average particle diameter can also be determined using a particle size distribution measuring device. As a measuring apparatus, FPIA-3000 (Malvern Corporation) can be mentioned as an example. The diameter of the filler in the film can be determined by observation with a metal microscope or observation with an electron microscope such as SEM. In this case, the number of samples for measuring the diameter of the filler is preferably 200 or more. In addition, when the shape of the filler is not spherical, the maximum length or the diameter of the spherical shape can be set as the particle size of the filler based on the plane image or cross-sectional image of the film containing the filler.

<Position of filler in film thickness direction>

Regarding the positions of the fillers 1A and 1B in the film thickness direction, FIG. 1B shows a state where the filler 1A of the first filler layer is exposed from one surface 2a of the resin layer 2 and the filler 1B of the second filler layer is exposed from the other surface 2b, However, the present invention includes the following aspects: the filler 1A of the first filler layer is exposed from a surface 2a of the resin layer 2, or the filler 1A is completely embedded in the resin layer 2 but is located at a position close to the surface 2a of the resin layer 2, and The filler 1B of the second filler layer is exposed from the other surface 2b of the resin layer 2 , or the filler 1B of the second filler layer is completely embedded in the resin layer 2 but located close to the surface 2b of the resin layer 2 . Here, the fillers 1A and 1B are completely embedded in the resin layer 2 but are located near the surfaces 2a and 2b. As an example, it means that the fillers 1A and 1B are not exposed from the resin layer 2 and the embedding rate described later is 110% or less, preferably 105% or less. If the fillers 1A, 1B are exposed from the surfaces 2a, 2b of the resin layer 2, the particle sizes of the fillers 1A, 1B may be the same or different. When the film containing the filler is constituted as an anisotropic conductive film, the trapping properties of the fillers 1A and 1B as conductive particles are remarkably improved during anisotropic conductive connection, which is preferable. Moreover, if the fillers 1A and 1B are embedded in the resin layer 2 and are close to the surfaces 2a and 2b thereof, the catching properties of the fillers 1A and 1B are not impaired and the viscosity of the film containing the fillers is improved, which is preferable. In particular, if the fillers 1A and 1B are not close to the surfaces 2a and 2b of the resin layer 2 by less than 0.1 μm, it is preferable to increase the capturing properties of the fillers 1A and 1B without losing the viscosity. In addition, it is preferable that the number density of the fillers is 5000 pieces/mm ² or more or that the area occupancy rate is 2% or more. Fillers 1A and 1B are embedded in the resin layer 2 and the surfaces 2a and 2b of the resin layer 2 are roughly the same plane. Thereby, compared with the case where the filler is exposed from the resin layer, the viscosity of the film containing the filler does not decrease, and compared with the case where the filling rate exceeds 100% and the filler is completely embedded, the film containing the filler is When constituted as an anisotropic conductive film, at the time of anisotropic conductive connection, the filler as the conductive particle is not easily affected by the flow of the resin, and the capture property is improved. On the other hand, if neither of the first filler layer nor the second filler layer is exposed from the resin layer 2 and is not located in the vicinity of the surfaces 2a and 2b of the resin layer 2, the film containing the filler is used as an isotropic film. When an anisotropic conductive film is constituted, the filler as conductive particles is easily affected by resin flow during anisotropic conductive connection, and there is a concern that the capture property may be lowered. Alternatively, since it is difficult to uniformly remove the resin in the vicinity of the filler, there is a concern that it will adversely affect the press-fitting of the filler. The same can be said for films containing fillers other than the anisotropic conductive film.

The distance between the intermediate portion of the adjacent fillers 1A in the first filler layer from the tangent plane of the surface 2a of the resin layer 2 to the deepest portion of the filler 1A (hereinafter, referred to as the amount of embedding) L1 and the particle size DA of the filler 1A The ratio (L1/DA), that is, the burying rate, is preferably 30% or more and 110% or less, more preferably 30% or more and 105% or less, more preferably more than 30% and 100% or less, particularly preferably 60% or more and below 100%. Similarly, regarding the filler 1B of the second filler layer, the distance (embedding amount) L2 from the tangent plane of the surface 2b of the resin layer 2 to the deepest part of the filler 1B in the intermediate portion of the adjacent fillers 1B and the particle size of the filler 1B The ratio of DB (L2/DB), that is, the burying rate is also preferably 30% or more and 110% or less, more preferably 30% or more and 105% or less, still more preferably more than 30% and 100% or less, particularly preferably Above 60% and below 100%. By setting the burying ratios (L1/DA) and (L2/DB) to 30% or more, it is easy to maintain the fillers 1A and 1B in a specific regular arrangement or a specific arrangement by the resin layer 2. 110% or less, preferably 105% or less, when the film containing the filler is constituted as an anisotropic conductive film, it is difficult to cause the flow of resin to cause conductive particles between terminals during anisotropic conductive connection. The filler flows uselessly. Moreover, in the film containing a filler, by making the embedding rate of the filler in the resin layer 2 uniform, the effect of improving the characteristic can be expected. As an example, when the performance of the optical film depends on the filler, if it has dispersibility (independence) in plan view and the embedded state has more than a certain regularity, it is presumed that the simply kneaded adhesive is applied Compared with the obtained ones, the improvement of performance or the stability of quality can be obtained.

The embedding rate of the filler 1A of the first packing layer and the embedding rate of the filler 1B of the second packing layer may be the same or different.

Here, the filler diameters DA and DB are the average of the filler diameters of the filler 1A of the first filler layer and the filler 1B of the second filler layer, respectively.

Moreover, in the present invention, the numerical values of the burying ratios (L1/DA) and (L2/DB) refer to 80% or more of the total number of fillers (such as conductive particles) contained in films containing fillers such as anisotropic conductive films , is preferably 90% or more, and more preferably 96% or more is the value of the buried ratio (L1/DA) and (L2/DB). The burial ratios (L1/DA) and (L2/DB) can be obtained by arbitrarily selecting 10 ^{regions with an area of 30 mm2} or more from a film containing a filler such as an anisotropic conductive film, and measuring the cross section of the film. SEM image observation was performed for a part, and a total of 50 or more fillers were measured. In order to further improve the accuracy, it can also be obtained by measuring more than 200 fillers.

As an example of a particularly preferable embedding aspect of the fillers 1A and 1B in the resin layer 2, the following aspect can be mentioned: as shown in FIG. % or less, and the fillers 1A, 1B are exposed from the surfaces 2a, 2b of the resin layer 2, respectively, and a depression 2x is formed in the resin layer 2 around the exposed fillers 1A, 1B; or as shown in FIG. 2, the fillers 1A, 1B The embedding rate of both sides is about 100%, and on the front and back of the resin layer 2, the fillers 1A and 1B are respectively on the same plane as the surfaces 2a and 2b of the resin layer 2. The fillers 1A and 1B are from the surface 2a of the resin layer 2. , 2b are exposed, and a recess 2x is formed in the resin layer 2 around the exposed fillers 1A, 1B. By forming the recess 2x, when the film containing the filler is formed as an anisotropic conductive film, the filler 1A and 1B as conductive particles are sandwiched between the terminals during anisotropic conductive connection. The resistance received from the resin by the flattening of the fillers 1A and 1B is reduced compared with the case where there is no depression 2x, and the catchability of the filler of the terminal is improved. As described above, the state of the filler and resin is specific, and it is expected to be characteristic in terms of performance and quality as a film containing a filler, as compared with a film obtained by coating a simply kneaded adhesive or the like.

On the other hand, when the film containing the filler is constituted as an anisotropic conductive film, when connecting electronic parts to each other using the anisotropic conductive film, it is preferable that air is not entrapped, as shown in FIG. 3 . As shown, the filling rate of the fillers 1A and 1B as conductive particles is about 100%, and the fillers 1A and 1B are embedded in the resin layer 2 so that the surface of the filler-dispersed layer 3 becomes flat.

In addition, when the burying rate exceeds 100%, as shown in FIG. 4 , it is preferable to form in the region just above the fillers 1A and 1B which are close to the surfaces 2a and 2b of the resin layer 2 of the fillers 1A and 1B. Sag 2y. By forming the depressions 2y, when the film containing the filler is constituted as an anisotropic conductive film, the pressure at the time of anisotropic conductive connection tends to concentrate on the filler 1A as the conductive particles, compared with the case where there is no depression 2y. , 1B, the catchability of the terminal fillers 1A, 1B is improved. As described above, the state of the filler and the resin is specific compared to the film obtained by coating a simply kneaded adhesive or the like as a film containing a filler, and thus can be expected to be characterized in terms of performance and quality.

<Arrangement of fillers>

In the film 10A containing the filler shown in FIG. 1A , the filler 1A of the first filler layer and the filler 1B of the second filler layer are arranged in a square lattice, respectively. Thus, in the film containing the filler of the present invention, the fillers 1A and 1B are preferably arranged regularly. As the regular arrangement, in addition to the square lattice shown in FIG. 1A , a lattice arrangement such as a rectangular lattice, a rhombic lattice, and a hexagonal lattice can be mentioned. As a regular arrangement other than a lattice arrangement, the particle row|line|column which arrange|positioned the filler linearly at a predetermined space|interval is juxtaposed by predetermined space|interval. By arranging the fillers 1A, 1B in a grid pattern, etc., when the film containing the filler is constituted as an anisotropic conductive film, in the anisotropic conductive connection, the fillers 1A, 1B which are conductive particles can be adjusted. 1B applies pressure evenly, thereby reducing unevenness in on-resistance.

The arrangement of the fillers 1A in the first filler layer and the arrangement of the fillers 1B in the second filler layer may be the same or different. When set to the same situation, for example, as shown in FIG. 5A and FIG. 5B as the filler-containing film 10B, in the plan view of the filler-containing film, the filler 1A of the first filler layer and the filler of the second filler layer can be 1B does not overlap, and a filler unit in which the filler 1A of the first filler layer and the filler 1B of the second filler layer are in contact or close to each other may be formed. In this case, the packing units are preferably arranged regularly without contacting each other. Thereby, the occurrence of a short circuit can be suppressed.

For example, the following packing unit can be formed: in the first packing layer and the second packing layer, the arrangement of the fillers 1A and 1B is the same, but the arrangement of one filler 1A is shifted by a certain distance in the direction of the film surface relative to the arrangement of the other filler 1B In the plan view of the film containing the filler, the filler 1A of the first filler layer and the filler 1B of the second filler layer partially overlap. In this case, if the filler unit 1C in which the filler 1A and the filler 1B are partially overlapped is formed as in the anisotropic conductive film in the form of the filler-containing film 10A shown in FIG. Since the film is an anisotropic conductive film, an effect that any one of the fillers 1A and 1B serving as conductive particles can be easily captured by the terminals can be expected during anisotropic conductive connection. That is, when the terminal 20 of the first electronic component 30 and the terminal 21 of the second electronic component 31 are anisotropically conductively connected using the anisotropic conductive film of the form of the filler-containing film 10A shown in FIG. 1A 6, if the filler 1A is located at the edge of the terminals 20 and 21, then in the top view of the film (anisotropic conductive film) containing the filler, the filler 1B exists in a position overlapping with the filler 1A. During pressing, even if the packing 1A or 1B is displaced, the terminals 20 and 21 are connected by any one of the adjacent packings 1A and 1B, so that the catchability of the packing of the terminal can be improved. In addition, in this case, if the resin flows during heating and pressurization, the distance between the fillers 1A and 1B will become longer, and thus the risk of short-circuiting will also be reduced. Furthermore, partially overlapping fillers 1A and 1B as described above is based on the diameter or number density of the fillers in the entire anisotropic conductive film of one aspect of the film containing the fillers, the distance between the fillers, the size of the connected terminals or the like. The distance between terminals, etc., is based on the premise that a short circuit will not occur in design even if the fillers 1A and 1B are partially overlapped. If the fillers 1A and 1B are partially overlapped, the effect of short circuit suppression will be satisfied and the catchability improvement will be easily satisfied. effect, so it is better. In addition, when the adjacent fillers 1A, 1B are substantially flush with the front and back surfaces 2a, 2b of the resin layer 2, respectively, or when exposed from the front and back surfaces 2a, 2b, these effects are further changed. large, so it is better. Furthermore, in the case where the film containing the filler is constituted as an anisotropic conductive film as described above, even if it is assumed that the filler 1A of the first filler layer and the filler 1B of the second filler layer in the film containing the filler described above are equal to the thickness of the film The directions are completely overlapped, and if used for anisotropic conductive connection, the resin will melt or flow due to heating and pressure during anisotropic conductive connection, and the positions of overlapping fillers 1A and 1B will be staggered, so practical No problem. The same can be said for the aspects other than the anisotropic conductive film.

On the other hand, when the arrangement of the fillers 1A of the first packing layer and the arrangement of the fillers 1B of the second packing layer are different, for example, it is preferable that the shapes of both arrangements are similar, and the arrangement has a common point. . It is not limited to the anisotropic conductive film.

In addition, the arrangement of the fillers 1A and the arrangement of the fillers 1B can be respectively used as part of the regular arrangement, and the arrangement of the fillers 1A and the arrangement of the fillers 1B can be combined to form a regular arrangement such as a lattice. For example, when the arrangement of the fillers 1A and the arrangement of the fillers 1B are combined into a hexagonal lattice, the arrangement of the fillers 1A has the arrangement of the hexagons contained in the hexagonal lattice, and the arrangement of the fillers 1B is set to be the arrangement of the hexagons. Arrangement of the center. Furthermore, the regular arrangement in this case is not limited to the hexagonal grid. In addition, there is no limitation as to which part of the regular arrangement formed by combining the arrangement of the fillers 1A and the arrangement of the fillers 1B. The regular arrangement formed by merging the arrangement of packing 1A with the arrangement of packing 1B can be deformed relative to the precise lattice arrangement, for example, the axes of the lattice that should be straight can be zigzag. By setting the arrangement conditions that are difficult to reproduce in this way, batch management can be performed, and traceability (traceability) can be imparted to the film containing the filler and the connection structure using the same. It is also effective for preventing forgery of films containing fillers or connecting structures using the same, for determining authenticity, preventing illegal use, and the like. In addition, in general, in anisotropic conductive connection, there is a possibility that a considerable number of conductive particles arranged in a straight line are not caught by the edge portion of the terminal. This situation can be avoided by making the arrangement in a zigzag shape. Therefore, it is easy to keep the capture number of the conductive particles of the terminal within a fixed range, which is preferable. In addition, by repeating such deformation, it is possible to easily judge whether or not the arrangement shape is appropriate by means of extraction inspection or the like.

Furthermore, the deformed arrangement of the fillers as described above can be formed by using one transfer mold, or by combining two transfer molds for the filler 1A and the transfer mold for the filler 1B. By using the transfer mold for filler 1A and the transfer mold for filler 1B to form an arrangement of fillers (such as conductive particles) in the entire film containing fillers such as anisotropic conductive films, various arrangements can be formed. It is easy to respond to design changes in a short period of time, which can contribute to the reduction of manufacturing costs, and can also reduce the ownership of manufacturing equipment, parts management, and manufacturing equipment for manufacturing films containing fillers, such as various anisotropic conductive films with different arrangements of fillers. The total cost associated with the manufacture of films containing fillers such as anisotropic conductive films, including maintenance and other costs. In the present invention, as described above, two types of transfer molds, a transfer mold for filler 1A and a transfer mold for filler 1B, can be used to design fillers (eg, conductive particles) from a plan view of the entire film containing fillers, such as anisotropic conductive films. A method for designing an arrangement state of fillers in an arrangement state, or a method for producing a film containing a filler such as an anisotropic conductive film using two types of transfer molds according to the design method.

In addition, about the filler 1A and the filler 1B, in the range which can obtain the effect of the invention which the film containing a filler intends, there may be a defect in the arrangement state. It can be confirmed by the regular existence of the specific direction of the film. In addition, the same effect as the above-mentioned modification can be obtained by repeating the lack of fillers in the longitudinal direction of the film, or by increasing or decreasing the number of leaks of the filler in the longitudinal direction of the film. That is, batch management can be performed, and traceability (traceability) can be imparted to the film containing the filler and the connection structure using the same. It is also effective for preventing forgery of films containing fillers or connecting structures using the same, for determining authenticity, preventing illegal use, and the like.

In each of the first filler layer and the second filler layer, the grid axis or the arrangement axis of the arrangement of the fillers 1A and 1B may be parallel to the longitudinal direction of the filler-containing film 10A such as an anisotropic conductive film, or may be parallel to the direction of the longitudinal direction of the filler-containing film 10A. The longitudinal direction of the film 10A containing a filler, such as an anisotropic conductive film, intersects. For example, in the case of forming an anisotropic conductive film, it is not particularly limited because it can be determined according to the terminal width, terminal pitch, etc. to be connected. For example, in the case of producing an anisotropic conductive film for fine pitches, as shown in FIG. 1A, the lattice axis A of the filler 1A of the first filler layer is set to the length of the film 10A containing the filler such as the anisotropic conductive film The side direction is inclined, and the angle θ formed by the long side direction (the short side direction of the film) of the terminal 20 connected by the film 10A containing a filler such as an anisotropic conductive film and the lattice axis A is preferably set to 6°~ 84°, more preferably 11° to 74°. Even in applications other than the anisotropic conductive film, by inclining in this way, the effect that the capture state can be stabilized can be expected.

The distance between the particles of the fillers 1A and 1B can be appropriately determined depending on whether or not the filler (eg, conductive particle) unit 1C is formed, the size of the terminals to be connected by a film containing a filler such as an anisotropic conductive film, and the terminal pitch. For example, regarding the distance L3 between the nearest particles of the adjacent fillers 1A in the first filler layer and the distance L4 between the nearest particles of the adjacent fillers 1B in the second filler layer ( FIG. 1A ), the anisotropic conductive In the case of a film, when the adjacent fillers 1A and 1B serving as conductive particles do not belong to one filler unit (conductive particle unit), the particle size of the fillers 1A and 1B is preferred from the viewpoint of suppressing short circuits. 1.5 times or more of DA and DB, and 66 times or less is preferable in terms of securing the minimum number of traps in the terminal packing and obtaining stable conduction. In particular, when a film containing a filler is formed as an anisotropic conductive film, when the anisotropic conductive film is adapted to micro-pitch COG (Chip On Glass, chip-on-glass), the distances between particles L3 and L4 are closest to each other. It is preferable to set it as 1.5~5 times of the particle size, and when dealing with the case of FOG (Film On Glass, coated glass) with a relatively large pitch, it is preferable to set it as 10~66 times of the particle size. In cases other than the anisotropic conductive film, it may be appropriately adjusted according to the characteristics.

Furthermore, as described below, when the packing unit 1C is formed by using the plurality of fillers 1A in the first packing layer, or when the packing unit 1C is formed by using the plurality of fillers 1B in the second packing layer, the In the case of the anisotropic conductive film, which is one aspect of the filler film, the distance between the fillers 1A of the first filler layer in one filler unit 1C is preferably set to be 1/4 times or less the particle size DA of the filler 1A, The fillers 1A may be in contact with each other. Similarly, the distance between the fillers 1B of the second filler layer in one filler unit 1C is preferably set to be 1/4 times or less the particle size DB of the fillers 1B, and the fillers 1B may be in contact with each other. In cases other than the anisotropic conductive film, it can be appropriately adjusted according to its characteristics.

<Number density of fillers>

The number density of the filler in the entire film containing the filler of the present invention can be appropriately adjusted according to its application or required properties, as well as the particle size and arrangement of the fillers 1A and 1B, and is therefore not particularly limited. The case of anisotropic conductive films. Since the manufacturing conditions of the film containing a filler are substantially the same as the case of the anisotropic conductive film, it can be considered that the conditions of the number density of the filler are also substantially the same. When the film containing the filler is formed as an anisotropic conductive film, the distance between the terminals of the electronic parts connected by the anisotropic conductive film and the distance between the fillers (conductive particles) 1A and 1B of the anisotropic conductive film can be determined. The particle size, arrangement, etc. are appropriately adjusted. For example, in order to suppress short circuits, the upper limit of the number density is preferably 70,000 pieces/mm ² or less, more preferably 50,000 pieces/mm ² or less, and still more preferably 35,000 pieces/mm ² or less. On the other hand, the lower limit of the number density is preferably 100 pieces/mm ² or more, more preferably 150 pieces/mm ² or more, in order to suppress cost, reduce fillers (conductive particles), and satisfy conduction performance. Preferably, it is 400 pieces/mm ² or more. In particular, in the case of a fine-pitch application where the connection area of the smallest terminal of the electronic components connected by the anisotropic conductive film is 2000 μm ^{2 or less, it is preferably 10,000 pieces/mm 2} or more. The design number density of the filler 1A of the first packing layer and the design number density of the filler 1B of the second packing layer may be the same or different.

When the filler-containing film is produced, when the filler is adhered to the longitudinal direction of the filler-containing film, when there is a tendency for the omission of the filler or the uneven distribution of the filler to inevitably increase, the first filler is preferred. One of the number density of the filler 1A of the layer and the number density of the filler 1B of the second filler layer gradually increases in the longitudinal direction of the film containing the filler, and the other gradually decreases, that is, an increase in the number density or The decreasing direction is the opposite direction in the first packing layer and the second packing layer. In the case where the average number density of the filler 1A in the first filler layer in the entire film containing the filler, such as an anisotropic conductive film, is the same, the number density of the filler is gradually increased or decreased as described above. One end 10Ap and the other end 10Aq of the film containing the filler, the number density of the filler 1A of the first filler layer and the number density of the filler 1B of the second filler layer are opposite, and one of the fillers in the whole film containing the filler The uniformity of number density is improved. In the case where the uniformity of the number density of the fillers in the entire surface is strongly required like an anisotropic conductive film, the difficulty of manufacture is reduced, and thus its effect can be expected. Moreover, the effect of cost reduction can be similarly anticipated in the anisotropic conductive film and other applications.

The number density of the fillers in the first filler layer or the second filler layer in the longitudinal direction of the film containing fillers such as anisotropic conductive films can be obtained by the following method: in the longitudinal direction of the film containing fillers In a region that is 20% or more of the total length of the film or 3 m or more, a plurality of positions (preferably 5 or more, more preferably 10 or more) are set at different positions in the longitudinal direction of the film containing the filler to be 100 μm or more on one side the rectangular region as a measurement of the area number density of the filler, the total area of the measurement area is preferably set to 2mm ² or more, using a metal microscope, measuring the number density of the filler measured in each area, and such averaging, or Take an image of the area of more than 20% of the total length of the film or more than 3m, and measure the number density of fillers by image analysis software (such as WinROOF, Sangu Shoji Co., Ltd., etc.). Moreover, the number density of fillers gradually The increase or decrease can be confirmed by monotonically increasing or decreasing the number density of the filler measured in each measurement area with respect to the longitudinal direction of the film containing the filler such as an anisotropic conductive film. In addition, the area|region of 100 micrometers x 100 micrometers becomes the area|region where one or more bumps exist in the connection object with the inter-bump space|interval 50 micrometers or less. Furthermore, the upper limit of one side of the measurement area can be appropriately adjusted according to the number density of the filler. In the case where it is obviously dense or sparse, for example, the number of fillers can be adjusted to be 200 or more, preferably 1,000 or more in terms of the total area of the filler.

When the film containing the filler is constituted as an anisotropic conductive film, the connection area of the smallest terminal of the electronic component connected by the anisotropic conductive film is 2000 μm ² or less. For spacing application, the number density of fillers 1A and 1B in total of the first filler layer and the second filler layer on one end 10Ap of the film (anisotropic conductive film) containing fillers NpAB and the first filler layer on the other end 10Aq The difference (NpAB-NqAB) of the number density NqAB of the fillers 1A and 1B in total with the second filler layer is preferably within ±2% with respect to the average ((NpAB+NqAB)/2), more preferably Within ±1.5%, more preferably within ±1%, when the connection area of the smallest terminal exceeds ^{the conventional spacing of 2000 μm 2} , (NpAB-NqAB) is preferably relative to ((NpAB+NqAB)/2) Within ±20%, more preferably within ±10%.

When the arrangement and number density of the designed fillers in the first filler layer and the second filler layer are set to be the same, as the step of forming the first filler layer and the second filler layer on the resin layer 2, the manufacturing process is performed. More preferably, as described below, when the filler 1A serving as the first filler layer is adhered to the resin layer 2 and when the filler 1B serving as the second filler layer is adhered to the resin layer 2, the resin layer 2 is preferably If the direction of movement is opposite, repeat the same step. Reversing the direction of travel in this way is also preferable in that, if there is a defect in the transfer mold for attaching the filler, the position of the defect on the film containing the filler such as the anisotropic conductive film is located in the film The front and back do not overlap, which can avoid the risk of the whole film becoming defective.

On the other hand, when the number densities of the fillers 1A and 1B of the first filler layer and the second filler layer are made different, from the viewpoint of improving the catchability of the filler of the terminal, it is preferable to use one of these fillers. The filler layer with a higher number density is set closer to the position of the outer interface of the film containing the filler, such as the anisotropic conductive film. In addition, when the filler layer is exposed to the outer surface of a film containing a filler such as an anisotropic conductive film, the exposed filler layer is required to suppress a decrease in the viscosity of the film containing a filler such as an anisotropic conductive film. It is preferable to set it as the one with the lower number density (the side with the lower number density). In this way, in the film containing the filler, the number density of the fillers 1A and 1B of the first filler layer and the second filler layer can be appropriately made different according to the required properties.

<Resin layer>

(viscosity of resin layer)

The minimum melt viscosity of the resin layer 2 is not particularly limited, and can be appropriately determined according to the application of the filler-containing film, the manufacturing method of the filler-containing film, and the like. For example, as long as the above-mentioned depressions 2x and 2y can be formed, it may be set to about 1000 Pa·s depending on the manufacturing method of the film containing the filler. On the other hand, as a method for producing a film containing a filler, when a method of holding the filler on the surface of the resin layer in a specific arrangement and pressing the filler into the resin layer is performed, the resin layer can be formed into a film. In other words, it is preferable to set the minimum melt viscosity of the resin to 1100 Pa·s or more. The recesses 2x and 2y may be located on both sides or only on one side (ie, either of the fillers 1A, 1B).

Further, as described in the method for producing a film containing a filler described below, a depression 2x is formed around the exposed portions of the fillers 1A and 1B pressed into the resin layer 2 as shown in FIG. 1B , or as shown in FIG. 4 . In terms of forming the depressions 2y directly above the fillers 1A and 1B pressed into the resin layer 2, it is preferably 1500 Pa·s or more, more preferably 2000 Pa·s or more, and still more preferably 3000 to 15000 Pa·s, More preferably, it is 3000-10000 Pa·s. As an example, the minimum melt viscosity can be obtained by using a rotary 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. In the temperature range of 30 to 200° C., the temperature increase rate was 10° C./min, the measurement frequency was 10 Hz, and the load on the measurement plate was changed by 5 g.

By setting the minimum melt viscosity of the resin layer 2 to a high viscosity of 1500 Pa·s or more, the useless movement of the filler when the film containing the filler is crimped to the article can be suppressed, especially when the film containing the filler is set in all directions In the case of the anisotropic conductive film, the conductive particles that should be held between the terminals can be prevented from flowing away due to the resin flow during the anisotropic conductive connection.

Furthermore, when the filler-dispersed layer 3 of the film 10A containing the filler is formed by press-fitting the fillers 1A and 1B into the resin layer 2, the resin layer 2 when the fillers 1A and 1B are press-fitted is set to one of the following high viscosity Adhesive body: When the fillers 1A, 1B are pressed into the resin layer 2 in such a way that the fillers 1A, 1B are exposed from the resin layer 2, the resin layer 2 is plastically deformed, and a depression 2x is formed in the resin layer 2 around the fillers 1A, 1B. (FIG. 1B); or as a high-viscosity viscous body: when the fillers 1A, 1B are pressed into the resin layer 2 without being exposed from the resin layer 2, the fillers 1A, 1B A recess 2y is formed on the surface of the resin layer 2 directly above (FIG. 4). Therefore, as for the viscosity of the resin layer 2 at 60°C, the lower limit 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 15000 Pa·s or less, more preferably 10000 Pa·s or less. This measurement can be 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.

Regarding the specific viscosity of the resin layer 2 when the fillers 1A and 1B are pressed into the resin layer 2, the lower limit is preferably 3000 Pa·s or more, more preferably 4000 Pa·s, depending on the shape and depth of the formed depressions 2x and 2y. Above, 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 2x around the fillers 1A, 1B exposed from the resin layer 2 (FIG. 1B), the flattening of the fillers 1A, 1B generated when the film containing the filler is crimped to the article is affected by the resin. The resistance is reduced compared to the case without depression 2x. Therefore, when the film containing the filler is used as an anisotropic conductive film, the conductive particles are easily pinched by the terminals at the time of anisotropic conductive connection, so that the conduction performance is improved, and the catchability is improved. Especially in the anisotropic conductive film, since fillers 1A and 1B as conductive particles are present on both sides of the resin layer 2, in order to reduce the resistance received from the resin, it is also preferable that the depressions 2x are located on either side, and more The best is located on both sides.

In addition, by forming depressions 2y on the surface of the resin layer 2 just above the fillers 1A and 1B that are buried because they are not exposed from the resin layer 2 (FIG. 4), compared with the case where there is no depression 2y, the film containing the fillers The pressure at the time of crimping the article tends to concentrate on the fillers 1A and 1B. Therefore, when the film containing the filler is used as an anisotropic conductive film, the conductive particles are easily pinched by the terminals at the time of anisotropic conductive connection, so that the trapping property is improved, and the conduction performance is improved. Especially in the anisotropic conductive film, for the same reason as described above, the recesses 2y are preferably located on either side, and more preferably on both sides. 2x and 2y may exist independently on each single side, or may be mixed.

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

The "recesses" 2x and 2y of the film containing the filler as shown in Figs. 1B and 4 can also be described from the viewpoint of "slope" or "undulation". Hereinafter, description will be made with reference to the drawings.

A filler-containing film 10A such as an anisotropic conductive film is constituted by the filler-dispersed layer 3 (Fig. 1B). In the filler-dispersed layer 3 , the fillers 1A and 1B are regularly dispersed on one side of the resin layer 2 in an exposed state. The filler layer is constituted as follows: in the plan view of the film, the fillers 1A and 1B are not in contact with each other, and the fillers 1A and 1B are regularly dispersed without overlapping each other in the film thickness direction, and the positions of the fillers 1A and 1B in the film thickness direction are matched. layer of filler layer.

The surfaces 2a and 2b of the resin layer 2 around each of the fillers 1A and 1B are formed with an inclination of 2x with respect to the tangent plane 2p of the resin layer 2 on the central portion between the adjacent fillers. Furthermore, as described below, in the film containing the filler of the present invention, undulations 2y may be formed on the surface of the resin layer immediately above the fillers 1A and 1B embedded in the resin layer 2 ( FIG. 4 ).

In the present invention, "inclined" means a state in which the flatness of the surface of the resin layer is impaired in the vicinity of the fillers 1A and 1B, a part of the resin layer is incomplete with respect to the above-mentioned tangent plane 2p, and the amount of resin decreases . In other words, the surface of the resin layer around the inclined system filler is defective with respect to the tangential plane. On the other hand, "wavy" means a state in which there is a corrugation on the surface of the resin layer just above the filler, and there is a portion having a height difference like the corrugation, so that the resin decreases. In other words, the resin amount of the resin layer directly above the filler is less than when the surface of the resin layer directly above the filler is in the tangential plane. These can be identified by comparing the portion corresponding to just above the filler with the flat surface portion between the fillers (FIG. 1B, FIG. 4). Furthermore, there are also cases where the starting point of the ups and downs exists in the form of an inclination.

As described above, by forming the inclination 2x around the fillers 1A and 1B exposed from the resin layer 2 ( FIG. 1B ), when the film containing the filler is formed as an anisotropic conductive film, when anisotropic conductive connection is made , In view of the flattening of the fillers 1A and 1B generated when the fillers 1A and 1B are clamped between the terminals, the resistance from the resin is reduced compared with the case where the inclination is not 2x, so the fillers on the terminals are easily clamped, so the conduction performance is improved. , again, the catchability is improved. The inclination preferably follows the outer shape of the packing. The reason for this is that, in addition to the effect of connecting more easily, the filler can be easily recognized, so that the inspection in the production of films containing fillers, such as anisotropic conductive films, is facilitated. In addition, some of these inclinations and undulations may disappear by hot pressing or the like of the resin layer, and the present invention includes such cases. In this case, the filler may be exposed on the surface of the resin layer at one point. Furthermore, when a film containing a filler is formed as an anisotropic conductive film, there are various electronic parts to be connected, and in terms of adjusting in accordance with these, it is desirable to have a high degree of freedom of design to satisfy various necessary conditions. Therefore, it can be used even if the inclination or undulation is reduced or partially eliminated.

Further, by forming undulations 2y ( FIG. 4 ) on the surface of the resin layer 2 immediately above the fillers 1A and 1B buried without being exposed from the resin layer 2 , as in the case of inclination, the films containing the fillers were used as the respective When an anisotropic conductive film is constituted, a pressing force from a terminal is easily applied to the filler during anisotropic conductive connection. In addition, due to the undulations, the amount of resin directly above the filler is reduced compared to the case where the resin is flatly stacked, so that the resin directly above the filler can be easily removed during connection, and the terminal and the filler are easily contacted. The capture performance is improved, and the conduction reliability is improved.

In terms of easily obtaining the effect of the inclination 2x ( FIG. 1B ) of the resin layer 2 around the exposed portion of the filler, or the undulation 2y ( FIG. 4 ) of the resin layer immediately above the filler, the exposure of the fillers 1A and 1B The ratio (Le/DA), (Le/DB) of the maximum depth Le of the slope 2x around the part to the particle diameters DA and DB of the fillers 1A and 1B is preferably less than 50%, more preferably less than 30%, Further preferably 20~25%, the ratio (Ld/DA), (Ld/DB) of the maximum diameter Ld of the inclination 2x around the exposed part of the fillers 1A, 1B to the particle diameters DA and DB of the fillers 1A, 1B (Ld/DA) Preferably it is more than 100%, more preferably 100~150%, the ratio of the maximum depth Lf of the undulation 2y of the resin directly above the fillers 1A and 1B to the particle sizes DA and DB of the fillers 1A and 1B (Lf/DA), ( Lf/DB) is greater than 0, preferably less than 10%, more preferably 5% or less.

Furthermore, the diameter Lc of the exposed portion of the fillers 1A and 1B can be set to be equal to or smaller than the particle diameters DA and DB of the fillers 1A and 1B, preferably 10 to 90% of the particle diameters DA and DB. In addition, one point of the top of the fillers 1A and 1B can be exposed, and DA and DB can be completely buried in the resin layer 2 so that the diameter Lc can be made zero.

In the present invention, the presence of the inclination 2x and the undulations 2y on the surface of the resin layer 2 can be confirmed by observing a cross section of a film containing a filler such as an anisotropic conductive film with a scanning electron microscope. can be confirmed. The tilt 2x and the undulation 2y can also be observed with an optical microscope and a metal microscope. In addition, the magnitude of the inclination 2x and the waviness 2y can also be confirmed by focusing adjustment during image observation. This is the same even after the inclination or undulation is reduced by thermocompression bonding as described above. The reason for this is that there are cases where traces are left.

(layer thickness of resin layer)

In films containing fillers such as the anisotropic conductive film of the present invention, the ratios (La/DA) and (La/DB) of the layer thickness La of the resin layer 2 to the average particle diameters DA and DB of all the fillers 1A and 1B are preferable It is 0.3 or more, more preferably 0.6 to 10, still more preferably 0.6 to 8, particularly preferably 0.6 to 6. As the average particle diameters DA and DB, when the average particle diameters of each of the filler 1A of the first filler layer and the filler 1B of the second filler layer are different, the average particle diameter can be set as the average. When the layer thickness La of the resin layer 2 is too large and the ratio exceeds 10, when the film containing the filler is formed as an anisotropic conductive film, the fillers 1A and 1B as conductive particles are likely to be easily connected during anisotropic conductive connection. The positional deviation occurs, and the catchability of the terminal fillers 1A and 1B is lowered. On the other hand, if the layer thickness La of the resin layer 2 is too small and the ratio is less than 0.3, it will be difficult to maintain the specific arrangement of the fillers 1A and 1B in the resin layer 2 .

(Composition of resin layer)

The resin layer 2 may be conductive or insulating depending on the application of the film containing the filler, and may be plastic or sclerosing. Preferably, the resin layer 2 may be formed of an insulating curable resin composition. An insulating thermally polymerizable composition of a thermally polymerizable compound and a thermally polymerizable initiator is formed. If necessary, the thermally polymerizable composition may contain a photopolymerization initiator. For these, known resins or compounds can be used. Hereinafter, the case of the insulating resin will be described by taking an example of an anisotropic conductive film which is one form of a film containing a filler.

When a thermal polymerization initiator and a photopolymerization initiator are used in combination, one that functions as both a thermally polymerizable compound and a photopolymerizable compound may be used, or a photopolymerizable compound may be included in addition to the thermally polymerizable compound. sexual compounds. It is preferable to contain a photopolymerizable compound in addition to the thermally polymerizable compound. For example, a cationic curing initiator is used as a thermal polymerization initiator, an epoxy resin is used as a thermal polymerizable compound, a photoradical polymerization initiator is used as a photopolymerization initiator, and an acrylate compound is used as a photopolymerizable compound .

As the photopolymerization initiator, a plurality of species that react to light having different wavelengths may be contained. Thereby, when the film containing the filler is formed as an anisotropic conductive film, it is possible to distinguish between the photocuring of the resin constituting the insulating resin layer in the production of the anisotropic conductive film, and the use in the anisotropic conductive connection. The wavelength used for light curing of the resin that adheres electronic parts to each other.

In the photocuring at the time of producing the anisotropic conductive film which is one aspect of the film containing a filler, all or a part of the photopolymerizable compound contained in the resin layer can be photocured. By the photocuring, the arrangement of the fillers 1A and 1B in the resin layer 2 is maintained or fixed, and the suppression of short circuits and the improvement of trapping properties can be expected. Moreover, the viscosity of the resin layer in the manufacturing process of an anisotropic conductive film can also be suitably adjusted by this photohardening.

The blending amount of the photopolymerizable compound in the 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 to the press-fit at the time of connection increases. Especially in the case of anisotropic conductive connection, it is preferable to set it as the above. This is to achieve both the flow of the resin and the indentation of the conductive particles held in the resin.

Examples of the thermally polymerizable composition include a thermally radically polymerizable acrylate-based composition containing a (meth)acrylate compound and a thermal radical polymerization initiator, and a thermally polymerizable acrylate-based composition containing an epoxy compound and a thermally cationic polymerization initiator. The thermal cationically polymerizable epoxy-based composition, etc. A thermal anion polymerizable epoxy-based composition containing a thermal anionic polymerization initiator may also be used instead of the thermal cationic polymerizable epoxy-based composition containing a thermal cationic polymerization initiator. Moreover, as long as it does not cause a particular hindrance, it is possible to use a plurality of thermally polymerizable compositions in combination. As an example of combined use, the combined use of a thermally cationically polymerizable composition and a thermally radically polymerizable composition, etc. can be 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 that do not generate nitrogen gas that cause bubbles can be preferably used.

The usage-amount of the thermal radical polymerization initiator is preferably 2 to 60 parts by mass relative to 100 parts by mass of the (meth)acrylate compound, since the curing failure will occur if it is too small, and the life of the product will be shortened if it is too large. parts, 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 of these, alicyclic epoxy resins, and the like. Use two or more of them in combination. Moreover, in addition to an epoxy compound, an oxetane compound may be used together.

As the thermal cationic polymerization initiator, those known as thermal cationic polymerization initiators for epoxy compounds can be used, for example, iodonium salts, periconium salts, phosphonium salts, ferrocenes, etc., which generate an acid by heat, can be used, In particular, aromatic perylene salts exhibiting 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. parts, 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 the film-forming resin include phenoxy resins, epoxy resins, unsaturated polyester resins, saturated polyester resins, urethane resins, butadiene resins, polyimide resins, polyamide resins, and polyolefin resins etc., and two or more of these can be used in combination. Among these, a phenoxy resin can be preferably used from the viewpoint 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.

In order to adjust the melt viscosity, the thermally polymerizable composition may contain an insulating filler in addition to the above-mentioned fillers 1A and 1B. It can be exemplified by silica powder, alumina powder, and the like. The insulating filler is preferably a small filler with a particle size 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. . The insulating filler contained in addition to the fillers 1A and 1B can be preferably used when the application of the film containing the filler is an anisotropic conductive film, but it may not be insulating depending on the application, for example, it may contain conductive microscopic of filler. When the film containing the filler is constituted as an anisotropic conductive film, the resin layer forming the filler-dispersed layer may appropriately contain a finer insulating filler (so-called nanofiller) different from the fillers 1A and 1B as necessary.

The filler-containing film of the present invention may further contain fillers, softeners, accelerators, antiaging agents, colorants (pigments, dyes), organic solvents, ion scavengers, etc. in addition to the above-mentioned insulating or conductive fillers.

<Variation of film containing filler>

(packing unit)

The filler-containing film of the present invention can take various forms with respect to the arrangement of the fillers.

_{For example, a filler unit 1C 1 is} formed from a plurality of fillers 1A in the first filler layer, and a filler unit 1C 1 is formed from a plurality of fillers in the second filler layer, such as a film 10C containing a filler such as an anisotropic conductive film as shown in FIGS. 7A and 7B . 1B forms a filler unit 1C ₂ , the filler units 1C ₁ and 1C ₂ do not contact each other, and do not overlap when viewed from a plan view of the film containing the filler, and the filler units 1C ₁ and 1C ₂ are arranged in a lattice shape. When in this case, the number of packing elements per a first layer of packing of the filler 1C 1A of example ₁ is set to 2 to 9, especially 2 to 4 can be set. In the packing unit, the packings 1A can be arranged in a row or assembled into a block. The number of packing elements per a second filler layer of a filler ₂ of 1B 1C also the same manner as, for example, be 2 to 9, especially 2 to 4 can be set. In the packing unit, the packings 1B can be arranged in a row or assembled into a block. In the case of the anisotropic conductive film, it can also be applied by arranging the filler unit in such a way that the risk of short circuit is reduced according to the terminal layout. In applications other than the anisotropic conductive film, it may be appropriately adjusted according to the purpose.

In the case of an anisotropic conductive film, in terms of enhancing the trapping properties of the filler (conductive particles) and suppressing short circuits, it is preferable that the filler unit 1C ₁ and the first filler layer of the first filler layer are composed of fillers arranged in a row. packing element 1C of the second filler layer _2, and preferably the length of the other side direction is non-parallel, particularly preferably as shown in FIG. 7A, FIG. 7B as orthogonal.

Furthermore, as in the film 10D containing the filler such as the anisotropic conductive film shown in FIGS. 8A and 8B , the plurality of fillers 1A of the first filler layer in contact with or close to each other and the second fillers in contact with or close to each other may be formed. A plurality of fillers 1B of the layers are in contact or close to each other to form a filler unit 1C. It is also preferable that the packing units 1C are regularly arranged so that they do not come into contact with each other. Moreover, it is preferable to set the number of fillers 1A of the first packing layer per one packing unit 1C to 2 to 9, especially 2 to 4, and to set the filler 1B of the second packing layer to 2 ~9, especially set to 2~4. Similarly to the above, in the case of an anisotropic conductive film, it can also be applied by arranging the filler unit so that the risk of short circuit is reduced according to the terminal layout. In applications other than the anisotropic conductive film, it may be appropriately adjusted according to the purpose.

In the case of an anisotropic conductive film, if the filler-containing film 10D having a plurality of filler units 1C formed of fillers (conductive particles) 1A, 1B is used for anisotropic conductive connection, and the film By pressing in the thickness direction, as shown in FIG. 9 , the fillers (conductive particles) 1A and 1B in contact with each other can be radially diffused, thereby separating the fillers (conductive particles) 1A and 1B from each other. In this case, as shown in FIG. 10, in the region between the terminals where the fillers (conductive particles) 1A, 1B are not pressed by the opposing terminals 20, 21, before the anisotropic conductive connection, the filler of the filler unit 1C is formed 1A and 1B will also be separated. Therefore, according to this filler-containing film 10D, short circuit between adjacent terminals can be suppressed. On the other hand, in the case where the fillers (conductive particles) 1A, 1B are located at the edge portions of the opposing terminals 20, 21 before the anisotropic conductive connection, at least one of the fillers 1A and 1B is formed by the anisotropic conductive connection will also be caught by terminals 20 and 21. Therefore, according to the film 10D containing the filler, the capturing efficiency of the conductive particles is improved. In applications other than the anisotropic conductive film, such filler unit 1C may be formed according to the purpose. It is considered that it is preferably applied to the case of pressing with a pressing roller. The reason for this is that it is easy to apply a pressing load in directions other than the thickness direction of the film.

(A state in which the gaps in the configuration of one packing layer are filled with another packing layer)

The omission can be eliminated by the following method: forming one of the first packing layer and the second packing layer with a specific arrangement and a specific number density in the design, and then confirming the arrangement and number density of the packing for the entire area to In accordance with the particle arrangement of the conductive particle layer, another filler layer is formed by filling the gaps in the particle arrangement of the filler layer as needed, and the filler of the whole film containing the filler, such as an anisotropic conductive film, is provided. for a specific configuration. Therefore, the number density of the filler layer formed later can also be changed in the longitudinal direction of the film containing the filler. By doing so, the yield of the film containing the filler can be improved, and the effect of cost reduction can be expected.

(Lamination of the second resin layer)

Like the film 10E containing the filler such as the anisotropic conductive film shown in FIG. 11A , the minimum melt viscosity of the surface layer of the filler-dispersed layer 3 is preferably lower than that of the second resin forming the resin layer 2 of the filler-dispersed layer 3 . Layer 4. In addition, the embedding ratio of the first filler layer and the second filler layer in the resin layer 2 is different. When the first filler layer is exposed from the resin layer more than the second filler layer, the anisotropy as shown in FIG. 11B can be obtained. A film 10F containing a filler such as a conductive film is generally laminated with a second resin layer 4 on the side of the first filler layer protruding from the resin layer 2 more, and a film containing a filler such as an anisotropic conductive film as shown in FIG. 11C may also be used. Like 10G, the second resin layer 4 is layered on the surface area of the resin layer 2 not protruding from the filler layer. By the lamination of the second resin layer 4, when an anisotropic conductive connection of electronic parts is performed using a film containing a filler such as an anisotropic conductive film, the space formed by the electrodes or bumps of the electronic parts can be filled and the bonding can be improved. sex. Furthermore, in the case of laminating the second resin layer 4, it is preferable that the second resin layer 4 is attached to the electronic component to be pressed with a tool (the resin layer 2 is attached to the electronic component placed on the stage). ). Thereby, the unintentional movement of the filler can be avoided, and the catchability can be improved.

If there is a difference in the minimum melt viscosity between the resin layer 2 and the second resin layer 4, the space formed by the electrodes or bumps of the electronic components is easily filled with the second resin layer 4, and it is expected to improve the mutual relationship between the electronic components. The effect of continuity. In addition, as the difference is larger, the amount of movement of the resin layer 2 existing in the filler-dispersed layer 3 is relatively smaller, so that the catchability of the filler of the terminal is easily improved. Practically, the minimum melt viscosity of the resin layer 2 and the second 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 a film containing a filler such as a long anisotropic conductive film is formed into a roll body, there is a risk of resin overflow or sticking, so 15 is practically preferable. the following. More specifically, the preferred minimum melt viscosity of the second resin layer 4 satisfies the above ratio and is 3000 Pa·s or less, more preferably 2000 Pa·s or less, especially 100 to 2000 Pa·s.

Furthermore, the second resin layer 4 can be formed by adjusting the viscosity of the same resin composition as the resin layer.

The thickness of the second resin layer 4 is preferably 4 to 20 μm. Or 1 to 8 times the diameter of the filler.

In addition, the minimum melt viscosity of the entire films 10E, 10F, and 10G containing fillers such as anisotropic conductive films obtained by combining the resin layer 2 and the second resin layer 4 is practically 8000 Pa·s or less, preferably 200~ Below 7000Pa‧s, preferably 200~4000Pa‧s.

(Lamination of the third resin layer)

The third resin layer may be provided on the opposite side to the second resin layer 4 via the resin layer 2 . The third resin layer can function as an adhesive layer.

The resin composition, viscosity and thickness of the third resin layer may be the same as or different from those of the second resin layer. The minimum melt viscosity of the anisotropic conductive film formed by combining the resin layer 2, the second resin layer 4 and the third resin layer is not particularly limited, but is practically 8000Pa·s or less, preferably 200~7000Pa·s or less , preferably 200~4000Pa·s.

(Other laminated versions)

Depending on the application of the film containing the filler, a plurality of filler-dispersed layers 3 may be stacked, a layer without filler like the second resin layer may be interposed between the stacked filler-dispersed layers, or a second resin layer may be provided on the outermost layer or the third resin layer.

<Production method of film containing filler>

The filler-containing film of the present invention having a single layer of the filler-dispersed layer 3 as the resin layer can be obtained, for example, by holding the filler 1A in a specific dispersion (preferably in a specific arrangement) on the resin layer 2 On one surface, the filler 1A is pressed into the resin layer 2 by a flat plate or a roller, and the filler 1B is similarly held in a specific dispersion (preferably in a specific arrangement) and pressed into the other side of the resin layer 2. a surface. In addition, when the filler is held on both sides of the resin layer in a specific dispersed state, it can be attached by various methods, such as using a coating roller or using a transfer mold, and it is preferable to keep the filler on one surface of the resin layer. The direction is reversed (180 degrees) from the direction in which the filler is held on the other surface. Thereby, when the front and back are observed integrally, the non-uniformity of the dispersion state of the filler on the front surface of the film and the non-uniformity of the dispersion state of the filler on the back surface of the film can be alleviated.

Moreover, a filler-containing film such as an anisotropic conductive film in which the second resin layer 4 is laminated on the filler-dispersed layer 3 can be obtained, for example, as shown in FIG. 12 . That is, the filler 1A is attached to one surface of the resin layer 2 (the same figure a) and pressed (the same figure b), and then the second resin layer 4 is layered on the area where the filler 1A is pressed (the same figure c). The filler 1B is attached to the surface of the resin layer 2 on the opposite side to the second resin layer 4 (d in the same figure), and the filler 1B is pressed into the resin layer 2 (the same in the figure e). In this way, the filler-containing film 10 such as an anisotropic conductive film in which the second resin layer 4 is laminated on the filler-dispersed layer 3 can be obtained. In this case, by appropriately setting the arrangement of the filler 1A pressed from one surface of the resin layer 2 and the arrangement of the filler 1B pressed from the other side, the fillers 1A and 1B are formed in contact with each other in a plan view. or close to the packing unit 1C.

Regarding films containing fillers such as an anisotropic conductive film in which the resin layer is formed from a single layer of the filler-dispersed layer 3 , and films containing fillers such as an anisotropic conductive film in which the second resin layer 4 is laminated on the filler-dispersed layer 3 , and further In the case where the third resin layer is laminated, as a method for adhering the fillers 1A and 1B to the resin layer 2 or a method for forming the resin layer 2 in which the fillers 1A and 1B are dispersed, there may be mentioned: transferring the filler using a transfer mold. The method of printing on the resin layer, the method of dispersing the filler on the resin layer, and the method described in Patent Document 1, the resin liquid containing the filler is applied to the resin using a coating roller having a regular groove on the surface such as a gravure coater method of layering or peeling off the film, etc. Furthermore, in the method of applying the resin liquid containing the filler to the release film using a coating roll, the resin layer thus formed can be used as the resin layer 2 . In the method described in Patent Document 1, as described above, compared with the method using a transfer mold, the fillers cannot be precisely and regularly arranged. The adhesion direction of the filler 1B in the longitudinal direction of the anisotropic conductive film is reversed, so even when the conductive particle layer is formed, there is a defect in the filler or a part with an uneven number density. 2. For the two packing layers, the missing parts of the fillers or the non-uniform part of the number density will not overlap. Therefore, the gaps of the fillers or the non-uniformity of the number density in each packing layer can affect the conduction characteristics. reduce.

Among the above-mentioned methods, it is preferable to use a transfer mold in terms of improving the accuracy of the arrangement of the fillers. As the transfer mold, for example, a well-known opening forming method such as photolithography can be used to form openings in inorganic materials such as silicon, various ceramics, glass, and metals such as stainless steel, or organic materials such as various resins. In addition, the transfer mold may take a shape such as a plate shape and a roll shape.

Generally, in the step of attaching fillers such as conductive particles to the resin layer using a transfer mold, in order to manufacture a film containing fillers such as a long anisotropic conductive film, conductive particles are sequentially applied from one end of the resin layer to the other end. However, as the process of attaching the filler continues, there is a tendency that the filler does not adhere to the resin layer due to clogging of the mold, and in films containing fillers such as anisotropic conductive films, the number of places where fillers are missing increases. Therefore, when the filler to be the first filler layer is attached from one end to the other end of the resin layer, the filler to be the second filler layer is preferably attached to one end from the other end of the resin layer. By reversing the direction of attachment in this way, the region of the first filler layer with a higher probability of existence of the conductive particles becomes a region of the second filler layer with a lower probability of the existence of the defect of the filler, and anisotropy can be made. The number density of fillers in the whole film containing fillers such as conductive films can be uniformed, which can eliminate excessive defects that affect the performance of fillers in anisotropic conductive connections (in the case of anisotropic conductive films, it is a poor connection. ). In addition, films containing fillers such as a long anisotropic conductive film are generally produced in the form of a package, and therefore, in the case where the adhesion directions of the first filler layer and the second filler layer are reversed and produced, it is preferable First, the resin layer is formed into a package while the filler that becomes the first filler layer is adhered from one end to the other end of the long resin layer, and then the package is rewound to become the first. 2. The filler of the filler layer is adhered to the resin layer in a direction opposite to the adhesion direction of the first filler layer, and the resin layer is formed into a package. Thereby, compared to rewinding the package on which the resin layer of the first filler layer was formed, and again attaching the filler to be the second filler layer to the resin layer in the same adhesion direction as that of the first filler layer, the step of Since it is simplified, the effect of cost reduction can be expected. Furthermore, when the adhesion direction is reversed, the blocked transfer mold can be replaced with a new one as needed, and can also be cleaned. In the case of a product in which the lack of filler can be tolerated to a certain extent, the frequency of replacement or cleaning of the transfer mold can be reduced, and thus the effect of cost reduction can also be expected in this respect.

In the method of applying the resin solution containing conductive particles to the resin layer or the release film using the coating roller, as the coating continues, the grooves on the surface of the coating roller will also be blocked, so the filler is preferably from the film. Coat the other end to the end.

Also, in the method of dispersing the filler in the resin layer, there is a case where the omission of the filler is periodically repeated. In this case, it is also preferable to make the filler to be the first filler layer adhere to the resin layer, and to make the When the filler of the second filler layer adheres to the resin layer, the moving direction of the resin layer is reversed.

It can be predicted that in the case of manufacturing by any of the above-mentioned production methods, in the case of manufacturing a film containing a filler such as a long anisotropic conductive film, a part that becomes a filler defect will inevitably be formed, but by The direction of adhesion of the filler in the longitudinal direction of the film containing the filler, such as the anisotropic conductive film of the first filler layer and the second filler layer, is reversed, so that the part that becomes the missing part can be located in the anisotropic conductive film and the like containing the filler. The membrane does not concentrate on one site, and the sites that become the leaks are scattered. Therefore, it can contribute to the improvement of the yield of the film containing a filler, such as an anisotropic conductive film, or the reduction of a manufacturing cost.

Furthermore, when the arrangement pattern or number density of the fillers in the first filler layer is the same as or different from the arrangement pattern or number density of the fillers in the second filler layer, an anisotropic conductive film, etc. The reversal of the adhesion direction of the first filler layer and the adhesion direction of the second filler layer in the filler-containing film is effective for reducing the unevenness of the number density of the filler in the filler-containing film such as an anisotropic conductive film. . For example, in the design of a film containing a filler such as an anisotropic conductive film, the arrangement of the filler is the same as that of the first filler layer and the second filler layer, and the number density of each is set to, for example, 400 pieces/mm ² , according to In the above-mentioned production method, the absolute value of the difference in number density between one end and the other end in the longitudinal direction of a film containing a filler such as an anisotropic conductive film actually produced is preferably 160 pieces/mm ² or less, more preferably 160 pieces/mm 2 or less. 80 particles/mm ² or less. Similarly, when the number density of the conductive particles of the first filler layer and the second filler layer is set to 65,000 particles/mm ² , respectively, the longitudinal direction of the anisotropic conductive film is The absolute value of the difference in number density between one end and the other end is preferably 26,000 pieces/mm ² or less, and more preferably 13,000 pieces/mm ² or less. That is, the absolute value of the difference in number density between one end and the other end in the longitudinal direction of a film containing a filler such as an anisotropic conductive film is the average of the number density of conductive particles in the total of the first filler layer and the second filler layer. That is, 800 to 130,000 pieces/mm ² is preferably within the range of ±20%, more preferably within the range of ±10%. Furthermore, the present invention does not exclude the case where the number density is less than 400/mm ^{2 .} In addition, although this invention was demonstrated using an anisotropic conductive film as an example, it is not limited to this. For example, in an optical film, it can be easily estimated that the performance can be stabilized by making the number density uniform. The same can be said for those directly related to appearance, such as matte films.

The filling amount of the fillers 1A and 1B attached to the resin layer 2 can be adjusted by the pressing force and temperature when the fillers 1A and 1B are pressed, and the presence or absence, shape and depth of the depressions 2x and 2y can be adjusted by pressing the fillers 1A and 1B. The viscosity, press-in speed, temperature, etc. of the resin layer 2 in time are adjusted. As a press-fitting method for making the embedding rate exceed 100%, a method of press-fitting using a press plate having convex portions corresponding to the arrangement of the fillers is exemplified.

Films containing fillers such as anisotropic conductive films formed into long strips are appropriately cut to form a product of films containing fillers such as anisotropic conductive films in the form of rolls. Therefore, the film containing a filler, such as the anisotropic conductive film of this invention, has a length of 5-5000 m, for example, and can be used as a roll body.

In order to economically perform connection of electronic parts using the anisotropic conductive film included in the film containing the filler, 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 too long, the conventional connection device used in the case of manufacturing electronic components using the anisotropic conductive film cannot be used, and the operability 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. Such an elongated body of the anisotropic conductive film is preferably used as a package wound around a core in terms of excellent handleability.

<How to use the film containing filler>

The filler-containing film of the present invention can be used in the same manner as the conventional filler-containing film, and the article is not particularly limited as long as the filler-containing film can be bonded. Various articles according to the application of the filler-containing film can be bonded by crimping, preferably by thermocompression bonding. At the time of this bonding, light irradiation may be utilized, and heat and light may be used together. For example, when the resin layer of the filler-containing film has sufficient adhesiveness to the article to which the filler-containing film is attached, the resin layer of the filler-containing film can be gently pressed against the article to obtain the resin layer containing the filler. A film-laminated body formed by laminating the film of the filler on the surface of an article. In this case, the surface of the article is not limited to a flat surface, and may have concavities and convexities, and may also be curved as a whole. When the article is in the form of a film or a flat plate, the film containing the filler can be attached to the article using a pressing roller. Thereby, the filler of the film containing the filler can also be directly bonded to the article.

In addition, the film containing the filler may be interposed between the two opposing articles, the two opposing articles may be joined by a thermocompression bonding roller or a crimping tool, and the filler may be sandwiched between the articles. In addition, the filler and the article may not be in direct contact with each other, and the article may be used to sandwich the film containing the filler.

In particular, when the film containing the filler is used as an anisotropic conductive film, the first electronic components such as IC chips, IC modules, and FPCs are bonded to FPC, glass, etc. through the anisotropic conductive film using a thermocompression bonding tool. It can be preferably used for anisotropic conductive connection of second electronic components such as substrates, plastic substrates, rigid substrates, and ceramic substrates. IC chips or wafers can be stacked and multi-layered using anisotropic conductive films. In addition, the electronic component connected by the anisotropic conductive film of this invention is not limited to the said electronic component. It can be used for various electronic parts which have been diversified in recent years.

Therefore, the present invention includes a connection structure formed by bonding the filler-containing film of the present invention to various articles by crimping, and a method for producing the same. In particular, when the film containing the filler is used as an anisotropic conductive film, it also includes: a method for producing a connection structure for anisotropically conductively connecting electronic components to each other using the anisotropic conductive film, or The obtained connection structure is a connection structure which anisotropically conductively connected electronic components to each other by the anisotropic conductive film of the present invention.

As a method of connecting electronic components using an anisotropic conductive film, when the anisotropic conductive film is composed of a single layer of a conductive particle-dispersed layer, it can be produced as follows: The parts are temporarily attached and temporarily crimped from the side where the conductive particles are embedded in the surface of the anisotropic conductive film, and the first electronic component such as an IC chip is superimposed on the surface of the temporarily crimped anisotropic conductive film without embedding conductive side of the particles and thermocompression bonding. When 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), A crimping method that combines light and heat is available. In this way, unexpected movement of the conductive particles can be suppressed to a minimum. Moreover, it can also be used by temporarily attaching the side where the conductive particles are not embedded to the second electronic component. Furthermore, the anisotropic conductive film may be temporarily attached to the first electronic component instead of the second electronic component.

Furthermore, when the anisotropic conductive film is formed of a laminate of the conductive particle-dispersed layer and the second insulating resin layer, the conductive particle-dispersed layer is temporarily attached to the second electronic parts such as various substrates and temporarily crimped. The first electronic components, such as an IC chip, are aligned and mounted on the side of the second insulating resin layer of the anisotropic conductive film temporarily crimped, and thermocompression bonding is performed. The second insulating resin layer side of the anisotropic conductive film may be temporarily attached to the first electronic component. Moreover, it can also be used by temporarily sticking the conductive particle-dispersed layer side to the first electronic component.

Example

Hereinafter, the anisotropic conductive film which is one aspect of the filler-containing film of the present invention will be specifically described by way of Examples.

(1) Manufacture of anisotropic conductive film

(1-1) Example 1A, 1B ~ Example 8

Prepare a high-viscosity first insulating resin layer (hereinafter, also referred to as layer A) for forming the conductive particle dispersion layer (i) in the proportions shown in Table 1, and (ii) having a lower viscosity than the first insulating resin layer The second insulating resin layer (hereinafter, also referred to as the N layer), and (iii) the resin composition of the third insulating resin layer forming the adhesive layer.

The resin composition for forming the first insulating resin layer (layer A) 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 a surface was formed on the PET film. The insulating resin layer of the thickness shown in 2. Similarly, the 2nd insulating resin layer (N layer) and the 3rd insulating resin layer (adhesive layer) were formed on the PET film by the thickness shown in Table 3, respectively.

On the other hand, the conductive particles (average particle size: 3 μm) of the first conductive particle layer are arranged in a square lattice as shown in FIG. 1A in plan view, and the areal density of the conductive particles is 800 in the case of FOG as shown in Table 2. /mm ² (Examples 1A, 1B), or as shown in Table 3, a mold was produced so that it became 10,000, 20,000, or 30,000 pieces/mm ² (Examples 2 to 8) for COG. That is, a mold was prepared so that the convex part pattern of the mold was arranged in a square lattice and the angle θ formed by the lattice axis and the short-side direction of the anisotropic conductive film was 15°, and pellets of a known transparent resin were melted. The resin mold having the concave portion in the arrangement pattern shown in FIG. 1A is formed into a roll shape by flowing into the mold, cooling and solidifying.

The concave part of the resin mold was filled with conductive particles (Sekisui Chemical Industry Co., Ltd., AUL703, average particle size: 3 μm), and the first insulating resin layer (layer A) was covered thereon, and was heated at 60° C., By pressing at 0.5 MPa, the conductive particles were bonded across a length of 300 m from one end to the other end of the first insulating resin layer. Next, the first insulating resin layer (layer A) was peeled off from the mold, and the conductive particles on the first insulating resin layer (layer A) were pressed into the first insulating resin layer (layer A) by a pressing roller (pressing conditions: 70° C., 0.5 MPa). The first insulating resin layer (layer A) forms the first conductive particle layer. The indentation rate was set to 100%, and the conductive particles and the surface of the first insulating resin layer (layer A) were made flush. A depression is formed around the pressed conductive particle with respect to the tangent plane of the first insulating resin layer on the central portion between the adjacent conductive particles.

Next, the second insulating resin layer (N layer) was bonded to the surface of the first insulating resin layer (A layer) on which the conductive particles were pressed by heating and pressurizing (45° C., 0.5 MPa), and the opposite side was attached to the second insulating resin layer (N layer). In the same manner as above, conductive particles were attached to the surface over a length of 300 m, and the conductive particles were pressed to form a second conductive particle layer, thereby obtaining a conductive particle-dispersed layer. In this case, the conductive particles (1st conductive particle layer) pressed first and the conductive particles pressed later (2nd conductive particle layer) are shifted by 3 μm in the film short-side direction. The moving direction of the first insulating resin layer to which the conductive particles were adhered was reversed from that in which the first conductive particle layer was formed. Moreover, also in the case of forming the 2nd conductive particle layer, the indentation rate was made into 100%, and the surface of the conductive particle and the 1st insulating resin layer (A layer) was made into the same plane. A depression is formed around the pressed conductive particle with respect to the tangent plane of the first insulating resin layer on the central portion between the adjacent conductive particles.

In Examples 1A, 2, 3, 4, 6, 7, and 8, the conductive particle-dispersed layers obtained as described above were used as anisotropic conductive films. In Example 1B, the moving direction of the film when the conductive particles serving as the first conductive particle layer were adhered to the first insulating resin layer and the moving direction of the film when the conductive particles serving as the second conductive particle layer were adhered to the first insulating resin layer same direction.

In Example 5, the third insulating resin layer (viscosity) was attached to the surface of the conductive particle dispersion layer on the opposite side of the second insulating resin layer (N layer) by heating and pressing (45°C, 0.5MPa). Floor).

In the area of 300 m in length from one end to the other end of the anisotropic conductive film in each embodiment, 10 rectangular areas with one side of 200 μm are set at different positions in the longitudinal direction as the measurement area for the number density of conductive particles. In the measurement area, the first conductive particle layer and the second conductive particle layer are observed with a metal microscope, and the number density of the conductive particles in each conductive particle layer is obtained. The tendency to change (tendency to increase or decrease) is studied. The results are shown in Table 2 and Table 3.

(1-2) Comparative Examples 1 to 3

The first insulating resin layer (A layer), the second insulating resin layer (N layer), and the third insulating resin layer (adhesive layer) having the resin compositions shown in Table 1 were formed in the same manner as in Example 1.

However, in Comparative Example 1, conductive particles were uniformly dispersed in the resin composition forming the first insulating resin layer (layer A), coated on a PET film, and dried to form an area density of 40,000 particles. /mm ² Conductive particle dispersion layer in which conductive particles are monodispersed.

In Comparative Example 2, the same procedure as in Example 2 was carried out, except that only the first conductive particle layer on the second insulating resin layer (N layer) side was formed as the conductive particle layer with an areal density of 40,000 pieces/mm ² An anisotropic conductive film is produced.

In Comparative Example 3, the same procedure as in Example 2 was performed except that only the second conductive particle layer on the opposite side of the second insulating resin layer (N layer) was formed as the conductive particle layer with an areal density of 40,000 pieces/mm ² The anisotropic conductive film is produced in this way.

Regarding the anisotropic conductive films of Comparative Examples 1 to 3, the variation tendency (increase or decrease tendency) of the number density of the conductive particles from one end to the other end was also examined. The results are shown in Table 2 and Table 3.

(2) Evaluation

(1) The anisotropic conductive films of Examples and Comparative Examples were cut with an area sufficient for connection, and (a) initial on-resistance and (b) on-resistance after reliability test were measured as follows , (c) particle trapping property, (d) short circuit rate, (e) temporary crimping property are measured or evaluated. The results are shown in Table 2 and Table 3.

In this case, as samples for evaluation, one end and the other end in the longitudinal direction of an anisotropic conductive film with a length of 300 m were used in Example 1A and Example 1B (anisotropic conductive film for FOG), and the In Examples 2 to 8 and Comparative Examples 1 to 3 (anisotropic conductive film for COG), the middle part in the longitudinal direction of the anisotropic conductive film (the part 150 m from one end) was used.

(a) Initial on-resistance

(a1) Evaluation of conduction characteristics of anisotropic conductive film for FOG (Examples 1A, 1B)

The sample of the anisotropic conductive film was sandwiched between the FPC for evaluation of conduction characteristics and the glass substrate, and the tool width was 1.5 mm, and heated and pressurized (200° C., 5 MPa, 5 seconds) to obtain each evaluation connector. The on-resistance of the obtained connector for evaluation was measured. The initial on-resistance is practically preferably 1Ω or less. Therefore, the initial on-resistance of 1Ω or less was set as OK, and the case where it exceeded 1Ω was set as NG.

Here, regarding the FPC for evaluation and the glass substrate, these terminal patterns correspond, and the dimensions are as follows. Moreover, when connecting the FPC for evaluation and a glass substrate, the longitudinal direction of an anisotropic conductive film was aligned with the short-side direction of a terminal.

FPC for evaluation of conduction characteristics

Terminal pitch 50μm

Terminal width: Spacing between terminals = 1:1

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

Glass base board

Electrode ITO coating (ITO coating)

Thickness 0.7mm

(a2) Evaluation of conduction characteristics of anisotropic conductive film for COG (Examples 2 to 8, Comparative Examples 1 to 3)

The samples of the anisotropic conductive film were sandwiched between the IC for evaluation of conduction characteristics and the glass substrate, and heated and pressurized (180° C., 80 MPa, 5 seconds) to obtain connectors for each evaluation. The on-resistance of the connector for evaluation was measured. The initial on-resistance is practically preferably 1Ω or less. Therefore, the initial on-resistance of 1Ω or less was evaluated as OK, and the case where it exceeded 1Ω was evaluated as NG.

Here, regarding the IC for evaluation and the glass substrate, these terminal patterns correspond, and the dimensions are as follows. Moreover, when connecting the IC for evaluation and a glass substrate, the longitudinal direction of an anisotropic conductive film was made to align with the short side direction of a bump.

IC for evaluation of conduction characteristics

Outline 1.8×20.0mm

Thickness 0.5mm

Bump size 30×85μm, distance between bumps 50μm, bump height 15μm

Glass base board

Glass material Corning 1737F

Appearance 30×50mm

Thickness 0.5mm

Electrode ITO wiring

(b) On-resistance after reliability test

The on-resistance after allowing the connector for evaluation produced in (a) to stand for 500 hours in a constant temperature bath with a temperature of 85° C. and a humidity of 85% RH was measured in the same manner as the initial on-resistance. The on-resistance after the reliability test is practically preferably 6Ω or less. Therefore, 6Ω or less is set as OK, and when it exceeds 6Ω, it is set as NG.

(c) Particle capture properties

(c1) Evaluation of particle trapping properties of anisotropic conductive film for FOG (Examples 1A, 1B)

In the connector for evaluation of conduction characteristics, the number of trapped conductive particles was measured for 100 regions of 25×400 μm in the FPC terminals of the connection portion, and the minimum trapped number was obtained, and the evaluation was performed according to the following criteria.

A (good): 3 or more

B (practically no problem): less than 3

(c2) Evaluation of particle trapping properties of anisotropic conductive film for COG (Examples 2 to 8, Comparative Examples 1 to 3)

Using the IC for evaluation of particle trapping properties, the IC for evaluation and the glass substrate corresponding to the terminal pattern are aligned with a 6 μm shift, and heat and pressure are applied (180° C., 80 MPa, 5 seconds), and the bumps of the IC for evaluation and the substrate are aligned. The number of trapped conductive particles was measured in 100 regions of 6 μm×66.6 μm where the terminals overlap, and the minimum trapped number was obtained, and evaluated according to the following criteria. Practically, the B evaluation or more is preferable.

IC for evaluation of particle capture performance

Outline 1.6×29.8mm

Thickness 0.3mm

Bump size 12×66.6μm, bump pitch 22μm, bump height 12μm

Particle Capture Performance Evaluation Criteria

A (good): 5 or more

B (practically no problem): 3 or more but less than 5

C (bad): less than 3

(d) Short circuit rate

(d1) Evaluation of short-circuit rate of anisotropic conductive film for FOG (Examples 1A, 1B)

Heat and pressurize (200°C, 5MPa, 5 seconds) the same FPC as the FPC used for the evaluation of conduction characteristics on an alkali-free glass (thickness 0.7mm), and measure the number of short circuits of the obtained connectors for evaluation. The short circuit occurrence rate was calculated|required from the measured number of short circuits and the number of gaps of the connector for evaluation, and it evaluated based on the following standards.

A (good): less than 50ppm

B (practically no problem): 50 ppm or more and less than 200 ppm

C (bad): 200ppm or more

(d2) Evaluation of Short Circuit Rate of Anisotropic Conductive Film for COG (Examples 2 to 8, Comparative Examples 1 to 3)

Using the IC for evaluation of the short-circuit rate, obtain a connector for evaluation in the same manner as (a) for the evaluation of the initial on-resistance, and measure the number of shorts of the obtained connector for evaluation. According to the measured number of shorts and The short-circuit occurrence rate was determined from the number of gaps in the connector for evaluation, and the evaluation was performed according to the following criteria.

IC for short-circuit rate evaluation (comb-teeth TEG (test element group) with 7.5 μm spacing)

Appearance 15×13mm

Thickness 0.5mm

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

Short circuit rate evaluation standard

A: less than 50ppm

B: 50ppm or more and less than 200ppm

C: 200ppm or more

(e) Temporary crimpability

Using a crimping tool, the anisotropic conductive film with PET film (width 1.5mm, length 50mm) is pressed against ITO glass at a temperature of 60°C or 70°C, a crimping pressure of 1MPa, and a crimping time of 1 second. Temporarily crimp. In this case, 350 μm thick silicone rubber was interposed between the crimping tool and the PET film as a buffer material. The PET film was peeled off about 100 temporary pressure-bonded samples obtained by pressing the anisotropic conductive film against the ITO glass in this manner. At this time, regarding the success of temporary crimping, for the sake of convenience, the case where none of the anisotropic conductive films was peeled off from the ITO glass together with the PET film was determined as OK, and the case where even one peeled off was determined as OK. for NG.

A: Above 60℃ is OK

B: OK above 70°C

C: NG above 70°C

As shown in Table 2, conductive particles are embedded in the surface of the front surface of the insulating resin layer at an embedding rate of 100%. From one end to the other end in the longitudinal direction of the anisotropic conductive film, the number density of the conductive particles In Example 1A in which the first conductive particle layer and the second conductive particle layer were in opposite directions, the increase and decrease tendencies were observed in on-resistance, reliability of on-resistance, and particle capture rate at one end and the other end of the anisotropic conductive film. , short-circuit rate, and temporary crimping properties were evaluated as favorable. On the other hand, in Example 1B in which the number density of the first conductive particle layer and the second conductive particle layer were the same, the number density of the total number of conductive particles in the first conductive particle layer and the second conductive particle layer was One end of the film having a lower value has a portion with poor particle capture ability, and the other end of the film having a higher number density obtained a good evaluation including particle capture ability. In addition, in this evaluation, since the connection area is sufficient, it is judged that there is no practical problem even if it is the B evaluation of less than three.

As shown in Table 3, the anisotropic conductive films of Examples 2 to 8 are also embedded with conductive particles on the front and back surfaces of the insulating resin layers at an embedding rate of 100%, respectively. The longitudinal direction of the anisotropic conductive films The increase and decrease in the number density of the conductive particles above tended to be in opposite directions in the first conductive particle layer and the second conductive particle layer, and were favorable in any evaluation item. In particular, from Example 2 and Example 5, it can be seen that the anisotropic conductive film of the present invention is excellent in temporary adhesion, excellent in workability, and excellent in particle trapping property even if no adhesive layer is provided.

In addition, according to Comparative Example 1, it was found that when the conductive particles were monodispersed in the conductive particle dispersion layer, both the particle trapping properties and the short-circuit rate were poor. From Comparative Example 2, it was found that if the conductive particle layer was formed only on the side of the second insulating resin layer (N layer), the particle trapping property was poor; from Comparative Example 3, it was found that if the conductive particle layer was formed only on the second insulating resin layer (N layer) side On the opposite side of the flexible resin layer (N layer), the temporary crimping property is poor. In addition, in Comparative Example 3, when the temporary pressure-bonding temperature was set to 75° C., the anisotropic conductive film was not peeled off from the ITO glass even when the number of temporary pressure-bonding samples was 500, so it was confirmed that Comparative Example 3 was based on Temporary crimping temperature setting is available for practical use.

(3) Transfer rate

For the anisotropic conductive film of Example 1, the transfer rate of the conductive particles at the time of forming the first conductive particle layer (the first time) and the transfer rate of the conductive particles at the time of forming the second conductive particle layer (the second time) were measured, respectively. Printing rate is measured.

Here, the transfer rate is the ratio of the number of conductive particles transferred to the first insulating resin layer with respect to the number of conductive particles filled in the resin mold.

The transfer rate was measured by using a metal microscope to measure the number of conductive particles in the first conductive particle layer or the second conductive particle layer ^{located in the area of 1 mm 2} of the lengths 0 m, 50 m, 100 m, 200 m, and 300 m of the anisotropic conductive film. Calculate its average. Furthermore, the first conductive particle layer (first time) was formed by transferring conductive particles in the direction from the 0 m side to the 300 m side of the anisotropic conductive film, and the second conductive particle layer (second time) was formed by It was formed by transfer from the 300m side to the 0m side of the anisotropic conductive film.

As a result, in the first conductive particle layer and the second conductive particle layer, the transfer rate exceeded 99.9% from the transfer starting point to 100 m, and the transfer rate decreased as the transfer progressed. However, the transfer rate of the total of the first conductive particle layer and the second conductive particle layer exceeded 99.9% at any point from the transfer starting point to 300 m.

Claims (18)

A filler-containing film comprising a resin layer and a filler-dispersed layer, the filler-dispersed layer having: a first filler layer composed of a filler dispersed in the resin layer in a single layer; and a second filler layer consisting of The depth different from that of the first filler layer is composed of a single layer of filler dispersed in the resin layer; and the filler of the first filler layer is exposed from a surface of the resin layer, or is close to the surface, and the filler of the second filler layer is Exposed from the other surface of the resin layer, or close to the other surface, in the longitudinal direction of the film containing the filler, the number density of the filler in the first filler layer and the number density of the filler in the second filler layer are calculated. One gradually increases and the other gradually decreases. The filler-containing film of claim 1, wherein the ratio (La/D) of the layer thickness (La) of the resin layer to the average particle size D of the filler (La/D) is 0.6-10. For the film containing fillers in the claim 1 of the scope of application, there are formed filler units in which the fillers of the first filler layer or the fillers of the second filler layer are in contact or close to each other, the filler units are not in contact with each other, and the filler units are regular arrangement. The filler-containing film as claimed in claim 1 of the scope of claim 1 is formed with filler units in which the filler of the first filler layer is in contact with or close to the filler of the second filler layer, the filler units are not in contact with each other, and the filler units are regularly arranged. The filler-containing film of claim 3, wherein, when viewed from above, the longitudinal direction of the filler unit of the first filler layer is not parallel to the longitudinal direction of the filler unit of the second filler layer. The filler-containing film of claim 1, wherein the filler-dispersed layer and the second resin layer are laminated, and the second resin layer has a lower minimum melt viscosity than the resin layer forming the filler-dispersed layer. As in the filler-containing film of claim 1, a third resin layer is further laminated. For the film containing fillers as claimed in claim 1 of the patent scope, two or more fillers may be used in combination. The filler-containing film of claim 1, wherein the surface of the resin layer near the filler has an inclination or elevation with respect to the tangent plane of the resin layer on the central portion between adjacent fillers In the inclination, the surface of the resin layer around the filler is defective relative to the above-mentioned tangent plane, and in the undulation, the resin amount of the resin layer directly above the filler is less than when the surface of the resin layer directly above the filler is located on the above-mentioned tangent plane . The filler-containing film according to any one of Claims 1 to 9, wherein the filler is conductive particles, the resin layer is an insulating resin layer, and the filler-containing film is used as an anisotropic conductive film. A method for producing a film containing a filler, which is the method for producing a film containing a filler according to any one of items 1 to 9 of the patent application scope, and is: keeping the filler on a surface of a resin layer in a specific dispersed state, The filler is pressed into the resin layer, and other fillers are kept on the other surface of the resin layer in a specific dispersed state, and the filler is pressed into the resin layer. A method for producing a film containing a filler, which is the method for producing a film containing a filler according to any one of items 1 to 9 of the scope of the patent application, wherein in the film containing a filler, the filler is conductive particles, and the resin layer is an insulating resin layer, and the above-mentioned film containing the filler is used as an anisotropic conductive film, and the above-mentioned production method is: keeping the filler on one surface of the resin layer in a specific dispersed state, and pressing the filler into the resin layer, and also making other The filler is held on the other surface of the resin layer in a specific dispersed state, and the filler is pressed into the resin layer. The method for producing a film containing a filler as claimed in claim 11 or 12 of the claimed scope, wherein when the filler is held in a specific dispersed state on both sides of the resin layer, the direction in which the filler is held in one surface of the resin layer is different from the direction in which the filler is held in the other surface. The direction of retaining the filler material is reversed in one surface. A film adhered body, which adheres the filler-containing film according to any one of claims 1 to 10 of the patent application scope to an article. A connecting structure, which is contained in any one of items 1 to 10 of the scope of application for a patent The filled membrane connects the first article to the second article. According to the connecting structure of claim 15, the first electronic part and the second electronic part are anisotropically conductively connected through the film containing the filler of claim 10. A method for manufacturing a connecting structure, which comprises crimping a first article and a second article through the film containing the filler according to any one of the claims 1 to 10 of the application scope. For the manufacturing method of the connecting structure of the claim 17, the first article and the second article are set as the first electronic component and the second electronic component, respectively, by using the filler-containing method according to the claim 10 of the claim. The film produces a connection structure in which the first electronic component and the second electronic component are anisotropically conductively connected by thermocompression bonding of the first electronic component and the second electronic component.

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