TW201829195A - Film containing filler - Google Patents

Abstract

This filler-containing film 10A, which is an anisotropic electrically-conductive film or the like, is provided with a filler-dispersed layer 3 having: a resin layer 2; a first filler layer that comprises a filler 1A dispersed in the form of a single layer in the resin layer 2; and a second filler layer that comprises a filler 1B dispersed in the form of a single layer in the resin layer 2 at a depth different from that of the first filler layer. The filler 1A of the first filler layer is exposed from one surface 2a of the resin layer 2 or is located close to the surface 2a, and the filler 1B of the second filler layer is exposed from the other surface 2b of the resin layer 2 or is located close to the surface 2b.

Description

   Film with filler   

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

The filler-containing film in which the filler is dispersed in the resin layer is being used in various applications such as a matting film, a capacitor film, an optical film, a marking film, an antistatic film, and an anisotropic conductive film (Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4).

As one aspect of a film containing a filler, for example, an anisotropic conductive film is widely used when mounting electronic parts such as IC chips. From the viewpoint of making the anisotropic conductive film cope with a high mounting density, in the anisotropic conductive film, conductive particles are being dispersed at a high density in the insulating resin layer. However, if the number density of the conductive particles is excessively increased, a short circuit easily occurs in a connection structure between electronic parts using an anisotropic conductive film.

In view of this, a method has been proposed in which a resin liquid containing conductive particles is applied to an insulating resin layer or a release film by using a coating roller having a regular groove on the surface, such as a gravure coater, when manufacturing an anisotropic conductive film. The conductive particles are regularly arranged in a single layer on the insulating resin layer (Patent Document 5). Further, a method has been proposed in which conductive particles dispersed in a specific arrangement are transferred to a first insulating resin layer and a second insulating resin layer using a transfer mold, respectively, and a first insulating resin to which conductive particles are transferred is transferred. The layer is bonded to the second insulating resin layer 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 Application Laid-Open No. 2015-138904

Patent Document 3: Japanese Patent Application Publication No. 2013-103368

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

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

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

According to the manufacturing method of the 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 easiness of causing a short circuit is lower than that in the case where the conductive particles are randomly arranged. However, since the conductive particles are arranged on a single surface of the anisotropic conductive film in a single layer, there is a limit for accurately arranging the conductive particles without causing a short circuit when the number density is increased.

According to the manufacturing method of the 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, the conductive particles in the entire anisotropic conductive film can be improved. Number density, and suppress the occurrence of short circuit. However, according to the method for manufacturing an anisotropic conductive film described herein, 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. If the first insulating resin layer and the second insulating resin layer are bonded together, there may be a risk that the viscosity of the surface of the anisotropic conductive film is reduced. At the time of attaching the anisotropic conductive film to electronic parts, The workability is lowered when the anisotropic conductive film is attached or pressure-bonded to an electronic part at a low temperature and fixed to the part.

In view of this, the object of the present invention is to increase the number density of the fillers in the film containing the filler represented by the anisotropic conductive film by having the first filler layer and the second filler layer at different depths. Improved functionality (for example, for high-density installations). Specifically, when the film containing a filler is constituted as an anisotropic conductive film, the problem is to suppress the occurrence of a short circuit in the connection structure between the electronic components, improve the connection reliability, and further make the anisotropic conductive Films and other filler-containing films have improved workability during temporary attachment or temporary compression bonding to make the film surface tacky.

The present inventors have found that the number density of fillers is increased by providing the first filler layer and the second filler layer due to the different depths of the resin layer, and in particular, the anisotropy of a form in which a film containing a filler is made In the case of a conductive film, in the case of a film containing a filler that suppresses the occurrence of a short circuit, if the filler is pressed into both the front and back surfaces of the resin layer, the first filler layer is exposed from one surface of the resin layer or provided near the surface. And if the second filler layer is exposed from the other surface of the resin layer or is provided near the surface, the conductive particles are easily captured by the terminals of the electronic parts to be anisotropically conductively connected, the connection reliability is improved, and the text is also easy to ensure. The tackiness of the film surface led to the invention. By having fillers on both sides in this way, it is possible to contribute to the improvement or improvement of performance, stability of quality, and cost reduction of films containing fillers.

That is, the present invention provides a filler-containing film including a resin layer and a filler dispersion layer, the filler dispersion layer having: a first filler layer composed of a filler dispersed in the resin layer in a single layer; and a second filler A layer composed of fillers dispersed in the resin layer in a single 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 one surface, the second The filler of the filler layer is exposed from or close to the other surface of the resin layer. In particular, as a preferred aspect of the 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 film containing the filler is used as anisotropy Conductive film.

In addition, the present invention provides a method for manufacturing the above-mentioned film containing a filler, which comprises: maintaining a filler in a specific dispersed state on one surface of a resin layer; and pressing the filler into the resin layer; 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 connection structure in which the film containing a filler is bonded to an article, and the first article and the second article are connected via the film containing a filler, and in particular, is used as an anisotropic conductive material. Film-containing filler A connection structure in which the first electronic component and the second electronic component are anisotropically conductively connected. Furthermore, the present invention provides a method for manufacturing a connection structure, which presses a first article and a second article through the film containing a filler, and a method for manufacturing a connection structure, which separates the first article and the second article, respectively. The first electronic component and the second electronic component are manufactured, and the first electronic component and the second electronic component are manufactured by thermocompression bonding the first electronic component and the second electronic component through a film containing a filler serving as an anisotropic conductive film. A connection structure formed by anisotropic conductive connection of electronic parts.

The anisotropic conductive film according to one aspect of the film containing a filler according to the present invention exists because the filler is exposed from or close to the surfaces of the front and back surfaces of the resin layer. Therefore, the anisotropic conductive film is formed as an anisotropic conductive film. The conductive particles are easily captured by the terminals of the electronic component to be anisotropically conductively connected. Therefore, 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 fillers in the entire film. Therefore, even if a filler is present at a high density in the entire film, the risk of lowering the viscosity of the film surface can be avoided. Furthermore, according to the film containing a 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 secured on the surface of the film. In addition to the improvement of the viscosity, it is also expected to provide a function different from the case where the filler is provided only on one surface by providing the filler not only on one surface but on both surfaces of the film containing the filler.

In addition, since the number density of the first filler layer and the number density of the second filler layer are respectively reduced compared to the number density of the fillers in the entire film, it becomes easy to accurately control the arrangement of the fillers in each filler layer. Even if the arrangement distance of the fillers in the whole film containing the filler such as an anisotropic conductive film is narrowed, the fillers can be accurately configured into a specific configuration. Therefore, combined with the improvement of the above-mentioned catchability, it is also suitable for micro-pitch connection, for example, it can be used for the connection of electronic parts with a terminal width of 6 μm to 50 μm and an interval between the terminals of 6 μm to 50 μm. In addition, as long as the effective connection terminal width (the width of a pair of terminals opposite to each other during the connection, which overlaps in a plan view) is 3 μm or more and the shortest terminal distance is 3 μm or more, it is possible to connect electronics 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 without contacting in the thickness direction and in a plan view. The same can be said for a matting film or the like directly related to the appearance. Because it can be adjusted on both sides, it is easy to help improve performance or quality and reduce costs.

1A, 1B‧‧‧ packing

1C, 1C ₁ , 1C ₂ ‧‧‧ packing unit

2‧‧‧ resin layer

2a, 2b ‧‧‧ Surface of resin layer

2x‧‧‧ sunken

2y‧‧‧ sunken

3‧‧‧ filler dispersion layer

4‧‧‧ 2nd resin layer

10, 10A, 10B, 10C, 10D, 10E, 10F, 10G

10Ap‧‧‧One end of the film containing filler

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

20, 21‧‧‧ terminals

30‧‧‧The first electronic part

31‧‧‧The second electronic part

A‧‧‧ Packing grid axis

DA, DB‧‧‧ particle size

La‧‧‧Resin layer thickness

L1, L2‧‧‧‧ Buried amount

L3‧‧‧The closest inter-particle distance between fillers in the first filler layer

L4‧‧‧The closest inter-particle distance between fillers in the second filler layer

Lc‧‧‧ diameter of exposed part of filler

Ld‧‧‧ Depression (inclined) maximum diameter

Le‧‧‧ Depression (inclined) maximum depth

Lf‧‧‧ Depth (undulation) maximum depth

θ‧‧‧ Angle formed by the long side direction of the terminal and the grid axis of the arrangement of conductive particles

FIG. 1A is a plan view showing the arrangement of fillers (conductive particles) of the filler-containing film (anisotropic conductive film in one form) 10A of the embodiment.

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

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

FIG. 3 is a cross-sectional view of a filler-containing film in which the filler is embedded in the first filler layer and the filler in the second filler layer is about 100%, and the filler is embedded in the resin layer such that the surface of the resin layer becomes flat.

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

FIG. 5A is a plan view showing the arrangement of fillers (conductive particles) of a film containing fillers (anisotropic conductive films in one form) 10B in the embodiment.

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

FIG. 6 is a cross-sectional view when an electronic component is anisotropically conductively connected using a film 10A containing a filler.

FIG. 7A is a plan view showing the arrangement of fillers (conductive particles) in a film 10C (anisotropic conductive film in one form) of the embodiment, and FIG.

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

FIG. 8A is a plan view showing the arrangement of fillers (conductive particles) of a film 10D (anisotropic conductive film in one form) containing a filler according to an embodiment.

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

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

10 is a cross-sectional view of a connection structure in which an anisotropic conductive connection of electronic parts is performed using a film 10D containing a filler.

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

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

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

FIG. 12 is a diagram illustrating the steps of a method for manufacturing a filler-containing film (anisotropic conductive film in one form) 10 having a second resin layer.

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

<Overall structure of film containing filler>

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

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

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

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

<Filler>

The fillers 1A and 1B can be obtained from known inorganic fillers (metals, metal oxides, metal nitrides, etc.), organic fillers (resin particles, rubber particles, etc.), mixed organic materials and inorganics, depending on the use of the film containing the filler. Fillers (such as particles made of a resin material at the center and metal-coated resin particles on the surface) formed by attaching insulating fine particles to the surface of conductive particles, and performing insulation treatment on the surface of conductive particles The selected ones are appropriately selected according to the properties required for use such as hardness and optical performance. For example, in an optical film or a matte film, a silicon dioxide filler, a titanium oxide filler, a styrene filler, an acrylic filler, a melamine filler, or various titanates can be used. For the capacitor film, titanium oxide, magnesium titanate, zinc titanate, bismuth titanate, lanthanum oxide, calcium titanate, strontium titanate, barium titanate, barium zirconate titanate, lead zirconate titanate, and the like can be used. And so on. The adhesive film may contain polymer-based rubber particles, silicone 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, palladium, alloy particles such as solder, metal-coated resin particles, and metal-coated resin particles having insulating fine particles adhered to the surface. Two or more types may be used in combination. Among them, a metal-coated resin particle is preferred in terms of the ease of maintaining contact with the terminal and the stable conduction performance by rebounding the resin particles after connection. In addition, the surface of the conductive particles may be subjected to an insulation treatment that does not impede the conduction characteristics by a known technique. The above-mentioned fillers listed according to the use are not limited to this use, and may also contain a filler-containing film as required. In addition, in the film containing a filler for each application, two or more kinds of fillers may be used in combination as necessary.

The shape of the filler can be appropriately selected from spherical, ellipsoidal, columnar, needle-like, combinations of these, etc. according to the use of the film containing the filler. A spherical shape is preferable because it is easy to confirm the arrangement of the filler and it is easy to maintain a uniform state. In particular, when a film containing a filler is configured as an anisotropic conductive film, it is preferable that the conductive particles as the filler are substantially true spheres. By using substantially true spheres as the conductive particles, for example, when an anisotropic conductive film in which conductive particles are arranged is manufactured using a transfer mold as described in Japanese Patent Application Laid-Open No. 2014-60150, the conductive particles smoothly pass on the transfer mold. Rolling, so that conductive particles can be filled in a specific position on the transfer mold with high accuracy. Therefore, the conductive particles can be accurately 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 or less in order to cope with unevenness in wiring height and to suppress an increase in on-resistance and a short circuit. the following.

The particle diameter of the filler 1A of the first filler layer and the particle diameter of the filler 1B of the second filler layer may be the same or different. When the filler-containing film is constituted as an anisotropic conductive film, the compressed state such as the flattening ratio after the anisotropic conductive connection between the fillers 1A and 1B as the conductive particles is made, especially when the conductive particles are metal. In the case where the resin particles are coated, these compression states are the same, and it is preferred that they be the same in terms of making the conduction performance stable. The materials and hardness (for example, compressive elastic modulus) of the fillers 1A and 1B may be the same or different.

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

<Position of filler in film thickness direction>

Regarding the positions in the film thickness direction of the fillers 1A and 1B, 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 one surface 2a of the resin layer 2, or the filler 1A is completely embedded in the resin layer 2 but is located 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 buried in the resin layer 2 but located near 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, the fillers 1A and 1B are not exposed from the resin layer 2 and the embedding rate will be described later. 110% or less, preferably 105% or less. If the fillers 1A and 1B are exposed from the surfaces 2a and 2b of the resin layer 2, the particle diameters of the fillers 1A and 1B may be the same or different. When a film containing a filler is constituted as an anisotropic conductive film, the catchability of the fillers 1A and 1B as conductive particles is significantly improved during anisotropic conductive connection, and therefore, it is preferable. In addition, if the fillers 1A and 1B are embedded in the resin layer 2 and are close to the surfaces 2a and 2b, the capture properties of the fillers 1A and 1B are not impaired and the viscosity of the film containing the filler is improved, which is preferable. In particular, if the fillers 1A and 1B are close to the surfaces 2a and 2b of the resin layer 2 with a thickness of less than 0.1 μm, the trapping properties of the fillers 1A and 1B are improved without impairing the viscosity, which is preferable. Further, it is preferable that the filler layer having a number density of 5,000 / mm ² or more or an area occupation ratio of 2% or more has the fillers 1A and 1B embedded in the resin layer 2 and the surfaces 2a and 2b of the resin layer 2 be Roughly the same plane. As a result, compared with the case where the filler is exposed from the resin layer, the viscosity of the film containing the filler is not reduced, and the film containing the filler is compared with the case where the embedding rate exceeds 100% and the filler is completely embedded. In the case of an anisotropic conductive film, the filler as conductive particles is less likely to be affected by the resin flow during anisotropic conductive connection, and the capture property is improved. On the other hand, if neither the first filler layer nor the second filler layer is exposed from the resin layer 2 and is not located near the surfaces 2a and 2b of the resin layer 2, the film containing the filler is used as the In the case of an anisotropic conductive film, during anisotropic conductive connection, the filler as a conductive particle is susceptible to the influence of resin flow, and there is a concern that the capture property is lowered. Alternatively, since it is difficult to uniformly exclude the resin near the filler, there is also concern about adverse effects on the pressing of the filler. This case can be said to be the same in a film containing a filler other than the anisotropic conductive film.

The distance from the tangent plane of the surface 2a of the resin layer 2 to the deepest part of the filler 1A between the adjacent fillers 1A in the first filler layer (hereinafter referred to as the embedding amount) L1 and the particle diameter DA of the filler 1A The ratio (L1 / DA), that is, the embedding rate is preferably 30% or more and 110% or less, more preferably 30% or more and 105% or less, more preferably 30% or more and 100% or less, and even more preferably 60% or more. And below 100%. Similarly, regarding the filler 1B of the second filler layer, the distance from the tangent plane of the surface 2b of the resin layer 2 to the deepest part of the filler 1B between the adjacent fillers 1B (the embedded amount) L2 and the particle diameter of the filler 1B The ratio of DB (L2 / DB), that is, the embedding rate, is also preferably 30% or more and 110% or less, more preferably 30% or more and 105% or less, more preferably 30% or more and 100% or less, and particularly preferably Above 60% and below 100%. By setting the embedding ratios (L1 / DA) and (L2 / DB) to 30% or more, it is easy to maintain the fillers 1A and 1B by the resin layer 2 in a specific regular arrangement or a specific arrangement, and by setting 110% or less, preferably 105% or less. When a film containing a filler is constituted as an anisotropic conductive film, it is not easy to cause conductive particles between terminals to flow between resins during anisotropic conductive connection. The filler flows uselessly. Moreover, in the film containing a filler, the effect of improving the characteristics can be expected by making the embedding rate of the filler in the resin layer 2 uniform. As an example, when the performance of the optical film depends on the filler, if it has the dispersibility (independence) in a plan view and the embedded state has more than a certain regularity, it is presumed to be coated with a simple kneading adhesive Compared with the obtained ones, the performance improvement or quality stability can be obtained.

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

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

In the present invention, the numerical values of the embedding ratios (L1 / DA) and (L2 / DB) refer to 80% or more of the total number of fillers (for example, conductive particles) included in a filler-containing film such as an anisotropic conductive film. It is preferable that 90% or more, and more preferably 96% or more become the values of the embedding rates (L1 / DA) and (L2 / DB). The embedding ratios (L1 / DA) and (L2 / DB) can be obtained by arbitrarily selecting 10 areas having an area of 30 mm ² or more from a film containing a filler such as an anisotropic conductive film, and the cross section of the film A part was observed with an SEM image, and a total of 50 or more fillers were measured. In order to further improve the accuracy, more than 200 fillers can be measured and calculated.

As an example of a particularly good embedding state of the fillers 1A and 1B in the resin layer 2, the following states can be cited: as shown in FIG. 1B, the embedding rate of both the fillers 1A and 1B is 60% or more and 100 % 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%. On the front side of the resin layer 2, the fillers 1A and 1B are on the same plane as the surfaces 2a and 2b of the resin layer 2, respectively. The fillers 1A and 1B are from the surface 2a of the resin layer 2. And 2b are exposed, and a recess 2x is formed in the resin layer 2 around the exposed fillers 1A and 1B. With the formation of the recess 2x, when a film containing a filler is configured as an anisotropic conductive film, it is generated when the fillers 1A and 1B which are conductive particles are sandwiched between the terminals during anisotropic conductive connection. The flatness of the fillers 1A and 1B reduces the resistance received from the resin compared with the case without the recess 2x, and the catchability of the filler of the terminal is improved. As a film containing a filler, as described above, since the state of the filler and the resin is specific, as compared with those obtained by applying a simple kneading adhesive or the like, characteristics can be expected in terms of performance or quality.

On the other hand, when a film containing a filler is constituted as an anisotropic conductive film, when electronic components are connected to each other using an anisotropic conductive film, it is preferable to be as shown in FIG. 3 in terms of not entraining air. As shown, the embedding rate of the fillers 1A and 1B as the 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 dispersion layer 3 becomes flat.

When the embedding rate exceeds 100%, it is preferable to form a region directly above the fillers 1A and 1B near the surfaces 2a and 2b of the resin layer 2 of the fillers 1A and 1B as shown in FIG. 4. Depression 2y. By forming the depression 2y, compared with the case without the depression 2y, when the film containing the filler is constituted as an anisotropic conductive film, the pressure at the time of anisotropic conductive connection is easier to concentrate on the filler 1A as the conductive particles. , 1B, the capture of the terminal fillers 1A, 1B is improved. As a film containing a filler, as described above, since the state of the filler and the resin is specific, as compared with those obtained by coating with a simple kneaded adhesive, etc., characteristics can be expected in terms of performance or quality.

<Arrangement of Fillers>

In the filler-containing film 10A shown in FIG. 1A, the fillers 1A of the first filler layer and the fillers 1B of the second filler layer are arranged in a square grid, respectively. Thus, in the film containing a 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, an oblique lattice, and a hexagonal lattice may be mentioned. Examples of the regular arrangement other than the lattice arrangement include a particle array in which fillers are linearly arranged at a specific interval and are arranged in parallel at a specific interval. When the fillers 1A and 1B are arranged in a regular pattern such as a lattice, when the film containing the filler is constituted as an anisotropic conductive film, when the anisotropic conductive connection is made, the fillers 1A, which are conductive particles, can be used. 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. In the same case, for example, as shown in FIG. 5A and FIG. 5B, the film containing the filler 10B, the filler 1A of the first filler layer and the filler of the second filler layer can be made in the plan view of the film containing the filler. 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 with or close to each other may also be formed. In this case, the filler units are preferably arranged regularly without contacting each other. Thereby, occurrence of a short circuit can be suppressed.

For example, the following filler units can be configured: in the first filler layer and the second filler layer, the arrangement of the fillers 1A and 1B is the same, but the arrangement of one filler 1A is shifted from the other filler 1B by a certain distance from the film surface direction. In a plan view of the film containing the filler, one of the filler 1A of the first filler layer and one of the fillers 1B of the second filler layer partially overlap. In this case, if, as shown in FIG. 1A, a filler-containing film 10A is an anisotropic conductive film, the filler unit 1C formed by the filler 1A and the filler 1B partially overlapping is formed. Since the film is an anisotropic conductive film, when the anisotropic conductive connection is used, it is expected that any one of the fillers 1A and 1B which are conductive particles can be easily captured by the terminal. That is, in the case where the terminal 20 of the first electronic component 30 and the terminal 21 of the second electronic component 31 are anisotropically conductively connected using an anisotropic conductive film in one form of the film 10A containing a filler shown in FIG. 1A. If the filler 1A is located at the edges of the terminals 20 and 21, as shown in FIG. 6, the filler 1B exists at a position overlapping the filler 1A in a plan view of the film containing the filler (anisotropic conductive film), and is therefore heated and heated. When pressing, even if the filler 1A or 1B is out of position, the terminals 20 and 21 are connected by any of the adjacent fillers 1A and 1B, so that the catchability of the filler of the terminal can be improved. Moreover, in this case, if the resin flows during heating and pressing, the distance between the fillers 1A and 1B will be farther, so the risk of short circuit will be reduced. Furthermore, the partial overlapping of the fillers 1A and 1B as described above is based on the diameter or number density of the fillers in the entire anisotropic conductive film in one aspect of the film containing the filler, the distance between the fillers, the size of the terminals of the connection, or The distance between the terminals is based on the premise that even if the fillers 1A and 1B are partially overlapped, no short circuit will occur in the design. If the fillers 1A and 1B are partially overlapped, the effect of short circuit suppression will be satisfied and the catchability will be easily improved. The effect is better. In addition, when the adjacent fillers 1A and 1B and the front and back surfaces 2a and 2b of the resin layer 2 become substantially the same plane, or when the front and back surfaces 2a and 2b are exposed, these effects are further changed. Large and therefore better. Furthermore, when the film containing a filler is configured 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 are at a film thickness The directions are completely overlapped. If it is used for anisotropic conductive connection, there may be cases where the resin melts or flows due to heating and pressure during anisotropic conductive connection. The positions of the overlapping fillers 1A and 1B are staggered, so it is practical. No problem. The same thing can be said in the aspect other than an anisotropic conductive film.

On the other hand, when the arrangement of the fillers 1A of the first filler layer and the arrangement of the fillers 1B of the second filler layer are different, for example, it is preferable that the arrangements have similarities in the arrangement. . It is not limited to an anisotropic conductive film.

In addition, the arrangement of the fillers 1A and the arrangement of the fillers 1B may be part of the regular arrangement, respectively, and the arrangement of the fillers 1A and the arrangement of the fillers 1B may be combined to form a regular pattern such as a grid. For example, in a case where the arrangement of the filler 1A and the arrangement of the filler 1B are combined into a hexagonal lattice, the arrangement of the filler 1A has an arrangement of hexagons included in the hexagonal lattice, and the arrangement of the filler 1B is set to become the hexagon The arrangement of the center. Moreover, the regular arrangement in this case is not limited to a hexagonal lattice. Moreover, there is no limitation as to which part of the arrangement of the fillers 1A and the arrangement of the fillers 1B becomes a regular arrangement formed by combining the two. The regular arrangement formed by merging the arrangement of the fillers 1A and the arrangement of the fillers 1B can be deformed relative to the precise lattice arrangement. For example, a lattice axis that should be a straight line can be jagged. By setting the arrangement conditions which are difficult to easily reproduce in this way, batch management can be performed, and the traceability (traceable property) can be provided to the film containing the filler and the connection structure using the same. It is also effective for preventing forgery of a film containing a filler or a connection structure using the same, determination of authenticity, and prevention of illegal use. In general, in anisotropic conductive connection, it is possible that a considerable amount of linearly arranged conductive particles will not be captured by the edge portion of the terminal. By making the arrangement zigzag, such a situation can be avoided. Therefore, it is easy to keep the number of captured conductive particles of the terminal in a fixed range, which is preferable. In addition, by repeating such deformations, it is possible to easily determine the appropriateness of the arrangement shape using extraction inspection or the like.

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

Furthermore, the filler 1A and the filler 1B may have gaps in the arrangement state within the range where the effects of the invention intended by the film containing the filler can be obtained. This can be confirmed by the regular existence of specific directions of the film. Moreover, the same effect as the above-mentioned deformation can be obtained by repeatedly filling the missing portion of the filler in the longitudinal direction of the film, or gradually increasing or decreasing the missing portion of the filler in the longitudinal direction of the film. That is, it is possible to perform batch management, and to provide a traceability (traceable property) to a film containing a filler and a connection structure using the same. It is also effective for preventing forgery of a film containing a filler or a connection structure using the same, determination of authenticity, and prevention of illegal use.

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

The inter-particle distance of the fillers 1A and 1B can be appropriately determined according to the presence or absence of formation of a filler (for example, conductive particle) unit 1C, the size of the terminals to be connected using a filler-containing film such as an anisotropic conductive film, and the terminal pitch. For example, the closest inter-particle distance L3 between adjacent fillers 1A in the first filler layer and the closest inter-particle distance L4 between adjacent fillers 1B in the second filler layer (FIG. 1A) are electrically conductive in anisotropy. In the case of a film, when the adjacent fillers 1A and 1B which are conductive particles do not belong to one filler unit (conductive particle unit), the particle diameter of the fillers 1A and 1B is preferred from the viewpoint of suppressing short circuits. DA and DB are 1.5 times or more, and from the viewpoint of ensuring the minimum number of captures of the terminal filler and obtaining stable conduction, it is preferably 66 times or less. Especially when the film containing a filler is constituted as an anisotropic conductive film, when the anisotropic conductive film is adapted to a fine-pitch COG (Chip On Glass), the distance between particles is closest to L3, L4. It is preferably set to 1.5 to 5 times the particle size. When dealing with a relatively large pitch of FOG (Film On Glass, coated glass), it is preferably set to 10 to 66 times the particle size. In the case other than the anisotropic conductive film, it may be appropriately adjusted according to its characteristics.

In addition, as described below, when a filler unit 1C is formed by using a plurality of fillers 1A in a first filler layer, or when a filler unit 1C is formed by using a plurality of fillers 1B in a second filler layer, In the case of an anisotropic conductive film that is one of the filler films, the distance between the fillers 1A of the first filler layer in one filler unit 1C is preferably 1/4 times or less the particle diameter 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 1/4 times or less the particle diameter DB of the fillers 1B, and the fillers 1B may be connected to each other. In the case other than the anisotropic conductive film, it may be appropriately adjusted according to its characteristics.

<Number density of filler>

The number density of the filler in the whole film containing the filler of the present invention is not particularly limited because it can be appropriately adjusted according to its use or required characteristics, and the particle diameter and arrangement of the fillers 1A and 1B. The following each can be applied In the case of an anisotropic conductive film. Since the manufacturing conditions of the film containing the filler are approximately the same as those of the anisotropic conductive film, it can be considered that the conditions of the number density of the filler are also approximately the same. When the film containing a filler is configured as an anisotropic conductive film, the distance between the terminals of the electronic parts connected by the anisotropic conductive film, the filler (conductive particles) 1A, 1B of the anisotropic conductive film can be used. The particle size, arrangement, and the like are appropriately adjusted. For example, 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 even more preferably 35,000 pieces / mm ² or less in order to suppress short circuits. On the other hand, regarding the lower limit of the number density, in order to suppress the cost and reduce the filler (conductive particles) and satisfy the conduction performance, it is preferably 100 pieces / mm ² or more, more preferably 150 pieces / mm ² or more, and more It is preferably 400 pieces / mm ² or more. In particular, in the case of a micro-pitch application in which the connection area of the smallest terminal of an electronic component connected by an 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 filler layer and the design number density of the filler 1B of the second filler layer may be the same or different.

When manufacturing a film containing a filler, when the filler is adhered to the long side direction of the film containing a filler, when there is a tendency that the defect of the filler or the unevenness of the distribution inevitably increases, 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 direction of the long side of the film containing the filler, and the other gradually decreases, that is, the increase in the number density or The direction of decrease is opposite to that of the first filler layer and the second filler layer. When the average of the number density of the fillers 1A of the first filler layer in the entire filler-containing film such as an anisotropic conductive film is made the same, the number density of the fillers 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 is opposite to the number density of the filler 1B of the second filler layer, and the number of fillers in the entire film containing the filler is The uniformity of the number density is improved. When the uniformity of the number density of the fillers in the entire surface is strongly required like an anisotropic conductive film, the ease of production is reduced, and the effect can be expected. In addition, the effect of cost reduction can be expected similarly in the anisotropic conductive film and other uses.

The number density of the fillers in the first filler layer or the second filler layer in the long-side direction of a film containing a filler such as an anisotropic conductive film can be determined as follows: in the long-side direction of the film containing a filler In the area where the total length of the film is 20% or more or 3m or more, a plurality of places (preferably 5 or more, more preferably 10 or more) are set at different positions in the long side direction of the film containing the filler (100 or more on one side). The rectangular area is used as a measurement area for the number density of fillers. The total area of the measurement area is preferably set to 2 mm ² or more. The number density of fillers in each measurement area is measured using a metal microscope, and these are averaged, or Take an image in the area of more than 20% or 3m of the total length of the above film, and measure the number density of the fillers with image analysis software (such as WinROOF, Mitani Corporation), and the number density of the fillers gradually The increase or decrease can be confirmed by the monotonous increase or decrease of the number density of the fillers measured in each measurement area relative to the long-side direction of the film containing the filler such as an anisotropic conductive film. In addition, a region having an area of 100 μm × 100 μm is a region in which one or more bumps exist in a connection target having an interval between bumps of 50 μm 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 measurement area. In the case of significantly denser or sparse, for example, the number of fillers can be adjusted to be 200 or more, preferably 1,000 or more, based on the total area.

When the film containing a filler is configured 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 pitch applications, the number density of the fillers 1A and 1B NpAB on the first filler layer 10Ap and the second filler layer on the one end of the film containing the filler (anisotropic conductive film) and the first filler layer on the other end 10Aq The difference (NpAB-NqAB) in the number density NqAB of the fillers 1A and 1B combined with the second filler layer is preferably within ± 2% of the average ((NpAB + NqAB) / 2) of these, and more preferably Within ± 1.5%, and more preferably within ± 1%, in the case where the smallest terminal connection area exceeds the regular pitch of 2000 μm ² , (NpAB-NqAB) is preferably better than ((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 a step of forming the first filler layer and the second filler layer in the resin layer 2, the manufacturing is performed. Specifically, it is preferable to make the resin layer 2 when the filler 1A that becomes the first filler layer is attached to the resin layer 2 and when the filler 1B that is the second filler layer is attached to the resin layer 2 as described below. Move in the opposite direction and repeat the same step. Reversing the direction of travel in this way is also preferable in the case where there is a defect in the transfer mold used to attach the filler, the position of the defect on the film containing the filler such as an anisotropic conductive film is on the film The front and back do not overlap, which can avoid the risk of the whole membrane becoming bad.

On the other hand, when the number density of the fillers 1A and 1B of the first filler layer and the second filler layer is different, it is preferable to improve the capture property of the filler of the terminal among these. The filler layer having a higher number density is positioned closer to the interface outside the filler-containing film such as an anisotropic conductive film. When the filler layer is exposed on the outer surface of a film containing a filler such as an anisotropic conductive film, the exposed filler layer is to suppress the decrease in viscosity of the film containing a filler such as an anisotropic conductive film. It is preferable to set it as the one with a low number density (the side with a low number density). In this way, the number density of the fillers 1A and 1B of the first filler layer and the second filler layer can be appropriately changed according to the required characteristics of the film containing the filler.

<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 film containing the filler, the method of manufacturing the film containing the filler, and the like. For example, as long as the above-mentioned depressions 2x and 2y can be formed, depending on the manufacturing method of the film containing the filler, it can also be set to about 1000 Pa · s. On the other hand, as a method for manufacturing a film containing a filler, when the 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, the minimum melt viscosity of the resin is preferably set to 1100 Pa · s or more. The depressions 2x, 2y may be located on both sides, or may be located on only one side (ie, any of the fillers 1A, 1B).

In addition, as explained in the method for manufacturing 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. In terms of forming a depression 2y just above the fillers 1A and 1B pressed into the resin layer 2, it is preferably 1500Pa · s or more, more preferably 2000Pa · s or more, and further preferably 3000 ~ 15000Pa · s, Furthermore, it is more preferably 3000 ~ 10000Pa‧s. The minimum melt viscosity can be obtained as an example using a rotary rheometer (manufactured by TA instruments), which is kept fixed at a measurement pressure of 5 g, and a measurement plate with a diameter of 8 mm is used. In a temperature range of 30 to 200 ° C, the temperature increase rate was 10 ° C / min, the measurement frequency was 10Hz, and the load variation on the measurement plate was determined to be 5g.

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

When the fillers 1A and 1B are pressed into the resin layer 2 to form the filler-dispersed layer 3 of the filler-containing film 10A, the resin layer 2 when the fillers 1A and 1B are pressed are set as follows. Viscous body: When the fillers 1A and 1B are pressed into the resin layer 2 in such a way that the fillers 1A and 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 and 1B. (Fig. 1B); Or set as follows: when the fillers 1A and 1B are pressed into the fillers 1A and 1B in such a way that the fillers 1A and 1B are not exposed from the resin layer 2 and are buried in the resin layer 2 A depression 2y is formed on the surface of the resin layer 2 directly above (FIG. 4). Therefore, regarding 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 further preferably 4500 Pa · s or more, and the upper limit is preferably 20,000 Pa · s or less, and more preferably 15,000 Pa · s or less, more preferably 10,000 Pa · s or less. This measurement can be performed by the same measurement method as the minimum melting viscosity, and it can be obtained by extracting a value 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, according to the shape or depth of the formed depressions 2x and 2y, the lower limit is preferably 3000 Pa · s or more, and more preferably 4000 Pa · s The above is further preferably 4500 Pa · s or more, and the upper limit is preferably 20,000 Pa · s or less, more preferably 15,000 Pa · s or less, and even more preferably 10,000 Pa · s or less. The viscosity is preferably obtained at 40 to 80 ° C, and more preferably 50 to 60 ° C.

As described above, since the recesses 2x (FIG. 1B) are formed around the fillers 1A and 1B exposed from the resin layer 2, the flattening of the fillers 1A and 1B generated when the film containing the filler is crimped to the article is received from the resin. The resistance is reduced compared to the case without a depression 2x. Therefore, in the case where the film containing the filler is an anisotropic conductive film, the conductive particles are easily pinched by the terminals during the anisotropic conductive connection, so that the conduction performance is improved and the capture property is improved. Especially in an anisotropic conductive film, since there are fillers 1A and 1B as conductive particles on both sides of the resin layer 2, in order to reduce the resistance received from the resin, it is also preferable that the depression 2x is located on either side, more Jiawei is on both sides.

In addition, by forming recesses 2y on the surface of the resin layer 2 directly above the fillers 1A and 1B which were buried because they were not exposed from the resin layer 2 (FIG. 4), compared with the case where there are no recesses 2y, The pressure when crimping to an article is easily concentrated on the fillers 1A and 1B. Therefore, when the film containing a filler is an anisotropic conductive film, the conductive particles are easily pinched by the terminals during the anisotropic conductive connection, so the catchability is improved and the conduction performance is improved. Especially in the anisotropic conductive film, for the same reason as above, the depression 2y is preferably located on either side, and more preferably on both sides. 2x and 2y can exist on each side alone or in combination.

<Instead of "tilt" or "undulation" of depression>

The "concavities" 2x, 2y of the film containing a filler as shown in Figs. 1B and 4 can also be explained from the viewpoint of "tilting" or "undulations". Hereinafter, description is made with reference to the drawings.

A filler-containing film 10A such as an anisotropic conductive film is composed of a filler dispersion layer 3 (Fig. 1B). In the filler dispersion 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 composed as follows: in a plan view of the film, the fillers 1A and 1B are not in contact with each other, and the fillers 1A and 1B are not regularly overlapped with each other in the film thickness direction and are regularly dispersed; Layer of filler layer.

On the surfaces 2a, 2b of the resin layer 2 around each of the fillers 1A, 1B, an inclination 2x is formed with respect to the tangent plane 2p of the resin layer 2 on the central portion between the adjacent fillers. In addition, 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 embedded directly above the fillers 1A and 1B of the resin layer 2 (FIG. 4).

In the present invention, the "tilt" means a state in which the flatness of the surface of the resin layer is damaged near the fillers 1A and 1B, and a part of the resin layer is incomplete with respect to the above-mentioned tangent plane 2p, and the amount of resin is reduced. . In other words, the surface of the resin layer around the oblique filler is defective with respect to the tangent plane. On the other hand, the term "undulation" means a state in which there is a ripple on the surface of the resin layer directly above the filler, and there is a portion having a height difference like a ripple, so 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 located on the tangent plane. These can be identified by comparing the portion directly above the filler with the flat surface portion (Fig. 1B, Fig. 4) between the filler. Moreover, there are also cases where the starting point of the undulation exists in an inclined form.

As described above, the inclination 2x is formed around the fillers 1A and 1B exposed from the resin layer 2 (Fig. 1B). When the film containing the filler is constituted as an anisotropic conductive film, the anisotropic conductive connection is formed. For the fillers 1A and 1B produced when the fillers 1A and 1B are clamped between the terminals, the flattening of the fillers 1A and 1B and the resistance received from the resin are reduced compared with the case where there is no tilt 2x. Therefore, the fillers on the terminals are easily clamped, so the conduction performance is improved. , And, catching improved. The slope is preferably contoured along the filler. The reason is that in addition to making it easier to show the effect of connection, it is also easy to identify the filler, so it is easy to perform inspections and the like in the production of an anisotropic conductive film such as a film containing a filler. In addition, the inclination and undulation may be partially disappeared by heat-pressing the resin layer or the like, and the present invention includes this case. In this case, the filler may be exposed on the surface of the resin layer at one point. In addition, when a film containing a filler is constituted as an anisotropic conductive film, there are various electronic components to be connected. In terms of adjustment in accordance with these, it is ideal that the degree of freedom of design is high to meet various necessary conditions. Therefore, it can be used even if the inclination or undulation is reduced or partially disappeared.

In addition, by forming the undulations 2y on the surface of the resin layer 2 directly above the fillers 1A and 1B which are buried because they are not exposed from the resin layer 2 (FIG. 4), the film containing the filler is used as each In the case of an anisotropic conductive film, a pressing force from a terminal is easily applied to a filler during an anisotropic conductive connection. In addition, by having undulations, the amount of resin directly above the filler is reduced compared to the case where the resin is stacked flat. Therefore, when connecting, it is easy to exclude the resin directly above the filler, and the terminal is easily in contact with the filler. Improved catchability and improved reliability.

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 directly above the filler, the exposure of the fillers 1A, 1B The ratio of the maximum depth Le of the part around the slope 2x to the particle diameters DA, DB of the fillers 1A, 1B (Le / DA), (Le / DB) is preferably less than 50%, more preferably less than 30%, Furthermore, it is preferably 20 to 25%. The ratio of the maximum diameter Ld of the inclined 2x around the exposed portions of the fillers 1A and 1B to the particle diameters DA and DB of the fillers 1A and 1B (Ld / DA) and (Ld / DB) It is preferably more than 100%, more preferably 100 to 150%. The ratio of the maximum depth Lf of the resin undulation 2y directly above the fillers 1A and 1B to the particle diameters DA and DB of the fillers 1A and 1B (Lf / DA), ( Lf / DB) is more than 0, preferably less than 10%, and more preferably 5% or less.

In addition, the diameter Lc of the exposed portions of the fillers 1A and 1B may be equal to or smaller than the particle diameters DA and DB of the fillers 1A and 1B, and preferably 10 to 90% of the particle diameters DA and DB. Moreover, 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 becomes zero.

In the present invention, the existence of the inclination 2x and the undulation 2y of the surface of the resin layer 2 can be confirmed by observing the cross section of a film containing a filler such as an anisotropic conductive film with a scanning electron microscope. Confirmable. The optical microscope and metal microscope can also be used to observe 2x tilt and 2y undulation. In addition, the magnitudes of the inclination 2x and the undulations 2y can also be confirmed by focus adjustment during image observation and the like. This is the same even if it is easy to reduce the tilt or undulation as described above by thermocompression bonding. The reason is that there are cases where traces are left.

(Layer thickness of resin layer)

In the filler-containing film such as the anisotropic conductive film of the present invention, the ratio of the layer thickness La of the resin layer 2 to the average particle diameters DA, DB (La / DA), and (La / DB) of all the fillers 1A and 1B is preferred. It is 0.3 or more, more preferably 0.6 to 10, still more preferably 0.6 to 8, and even more preferably 0.6 to 6. As the average particle diameters DA and DB, when the average particle diameter of each of the filler 1A of the first filler layer and the filler 1B of the second filler layer is different, these average values can be used. If the layer thickness La of the resin layer 2 is too large, and the ratio exceeds 10, when a film containing a filler is constituted as an anisotropic conductive film, it is easy to use as fillers 1A and 1B for conductive particles in anisotropic conductive connection. Position deviation occurs, and the catchability of the fillers 1A and 1B of the terminal is reduced. 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 is difficult to maintain a 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 a filler, and may be plastic or hardenable. It is preferably formed of an insulating hardenable resin composition. The insulating polymerizable composition of the thermal polymerizable compound and the thermal polymerization initiator is formed. If necessary, the thermally polymerizable composition contains a photopolymerization initiator. These may use well-known resins or compounds. In the following, the case of an insulating resin is described by taking an anisotropic conductive film as one example of a film containing a filler as an example.

When a thermal polymerization initiator and a photopolymerization initiator are used in combination, those which function as both a thermally polymerizable compound and a photopolymerizable compound may be used, and a photopolymerization 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 hardening initiator is used as the thermal polymerization initiator, an epoxy resin is used as the thermal polymerizable compound, a photo radical polymerization initiator is used as the photopolymerization initiator, and an acrylate compound is used as the photopolymerizable compound. .

The photopolymerization initiator may contain a plurality of species that react with light having different wavelengths. In this way, when a film containing a filler is constituted as an anisotropic conductive film, it is possible to distinguish between photo-hardening of a resin constituting an insulating resin layer when manufacturing an anisotropic conductive film, and use of an anisotropic conductive connection. The wavelength used for the light curing of the resin that is used to bond electronic parts to each other.

In the case of photocuring in the production of an anisotropic conductive film which is one aspect of a film containing a filler, all or a part of the photopolymerizable compound contained in the resin layer can be photocured. By this photo-hardening, the arrangement of the fillers 1A and 1B in the resin layer 2 is maintained or fixed, and it is expected that suppression of short-circuits and improvement in catchability can be expected. Moreover, the viscosity of the resin layer in the manufacturing process of an anisotropic conductive film can also be adjusted suitably 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 even more preferably less than 2% by mass. The reason for this is that if the photopolymerizable compound is too much, the thrust force applied to the press-fitting at the time of connection increases. Especially in the case of anisotropic conductive connection, it is preferable to set it as mentioned above. This is for the purpose of balancing resin flow and press-fitting of conductive particles held in the resin.

Examples of the thermally polymerizable composition include a thermal radically polymerizable acrylate-based composition including a (meth) acrylate compound and a thermal radical polymerization initiator, an epoxy compound, and a thermal cationic polymerization initiator. Thermal cationic polymerizable epoxy-based composition. A thermal anionic polymerizable epoxy-based composition including a thermal anionic polymerization initiator may be used instead of the thermal cationic polymerizable epoxy-based composition including a thermal cationic polymerization initiator. In addition, as long as there is no particular obstacle, a plurality of thermally polymerizable compositions may be used in combination. Examples of the combined use include a combination of a thermal cationic polymerizable composition and a thermal radical polymerizable composition.

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 or a difunctional or more polyfunctional (meth) acrylate-based monomer can be used.

Examples of the thermal radical polymerization initiator include organic peroxides and azo compounds. In particular, organic peroxides which do not generate nitrogen gas which causes bubbles can be preferably used.

When the amount of the thermal radical polymerization initiator used is too small, it may cause poor curing, and if the amount is too large, the product life may be reduced. Therefore, it is preferably 2 to 60 parts by mass relative to 100 parts by mass of the (meth) acrylate compound. Parts, more preferably 5 to 40 parts by mass.

Examples of the epoxy compound include bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, modified epoxy resins, and alicyclic epoxy resins. Use 2 or more types together. Further, in addition to the epoxy compound, an oxycyclobutane compound may be used in combination.

As the thermal cationic polymerization initiator, those known as thermal cationic polymerization initiators for epoxy compounds can be used. For example, sulfonium salts, sulfonium salts, sulfonium salts, ferrocene, etc., which generate an acid by heat, can be used. In particular, an aromatic sulfonium salt exhibiting good latentness to temperature can be preferably used.

As for the amount of the thermal cationic polymerization initiator, if it is too small, there is a tendency of poor curing, and if it is too much, the product life tends to decrease. Therefore, it is preferably 2 to 60 masses 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 resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, amine ester resin, butadiene resin, polyimide resin, polyimide resin, and polyolefin resin. You can use these 2 or more types together. Among these, a phenoxy resin can be preferably used from a viewpoint of film formability, processability, and connection reliability. The weight average molecular weight is preferably 10,000 or more. Examples of the silane coupling agent include epoxy-based silane coupling agents and acrylic silane-based coupling agents. 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 fillers 1A and 1B. Examples thereof include silica powder and alumina powder. It is preferably a minute filler having an insulating filler particle diameter of 20 to 1000 nm, and the blending amount is preferably 5 to 50 parts by mass relative to 100 parts by mass of a thermally polymerizable compound (photopolymerizable compound) such as an epoxy compound. . Insulating fillers other than the fillers 1A and 1B can be preferably used when the use of the filler-containing film is an anisotropic conductive film. Depending on the application, the insulating filler may not be insulating. For example, it may contain small conductive particles. The filler. When a film containing a filler is constituted as an anisotropic conductive film, the resin layer forming the filler dispersion layer may appropriately contain a smaller insulating filler (so-called nano filler) different from the fillers 1A and 1B, if necessary.

The filler-containing film of the present invention may contain fillers, softeners, accelerators, anti-aging agents, colorants (pigments, dyes), organic solvents, ion trapping agents, and the like in addition to the insulating or conductive fillers described above.

<Changes of Filler-containing Film>

(Stuffing unit)

The filler-containing film of the present invention can take various forms regarding the arrangement of the filler.

For example, an anisotropic conductive film such as an anisotropic conductive film shown in FIG. 7A and FIG. 7B can be mentioned. A filler unit 1C _{1 is} formed by a plurality of fillers 1A in a first filler layer, and a plurality of fillers in a second filler layer are provided. 1B forms a filler unit 1C ₂ , the filler units 1C ₁ , 1C ₂ are not in contact with each other, and do not overlap in a plan view of the film containing the filler, and the filler units 1C ₁ , 1C ₂ are arranged in a grid. In this case, the number of fillers 1A per one filler unit 1C ₁ of the first filler layer may be set to, for example, 2 to 9, and particularly, may be set to 2 to 4. In the packing unit, the packings 1A may be arranged in a row, or may be assembled into a block. The number of fillers 1B per one filler unit 1C _{2 in} the second filler layer is also the same, for example, it can be set to 2 to 9, and in particular, it can be set to 2 to 4. In the packing unit, the packings 1B may be arranged in a row, or may be assembled into a block. In the case of an anisotropic conductive film, it can also be applied by arranging a filler unit in such a manner that the risk of short circuit becomes low according to the terminal layout. For 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 improving the trapping property of the filler (conductive particles) and suppressing short circuits, it is preferred that the filler units 1C ₁ and ₁ 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.

In addition, as shown in FIG. 8A and FIG. 8B, the filler 10A and other filler-containing films may be used, such that the plurality of fillers 1A of the first filler layer in contact with or close to each other and the second filler in contact with or close to each other The plurality of fillers 1B of the layer are in contact with or in proximity to form a filler unit 1C. The filler units 1C are also preferably arranged in a regular arrangement without contacting each other. In addition, it is preferable that the number of fillers 1A of the first filler layer per 1C of the filler unit is 2 to 9, especially 2 to 4, and that the filler 1B of the second filler layer is 2 ~ 9, especially 2 ~ 4. It is also similar to the above, and in the case of an anisotropic conductive film, it can also be applied by arranging a filler unit so that the risk of a short circuit becomes low according to a terminal layout. For 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 a filler-containing film 10D having a plurality of filler units 1C formed of fillers (conductive particles) 1A, 1B is used in this way for anisotropic conductive connection, By pressing in the thick direction, as shown in FIG. 9, the fillers (conductive particles) 1A, 1B that are in contact with each other can be diffused radially, thereby separating the fillers (conductive particles) 1A, 1B from each other. In this case, as shown in FIG. 10, in the area between the terminals where the fillers (conductive particles) 1A, 1B are not pressed by the opposed terminals 20, 21, before the anisotropic conductive connection, the filler of the filler unit 1C is formed. 1A and 1B will also separate. Therefore, according to this film 10D containing a filler, a 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 opposed terminals 20, 21 before the anisotropic conductive connection, at least one of the fillers 1A and 1B is connected by the anisotropic conductive connection Those will also be captured by terminals 20,21. Therefore, according to the film 10D containing a filler, the capture efficiency of conductive particles is improved. In applications other than an anisotropic conductive film, such a filler unit 1C may be formed according to the purpose. It is considered that it is preferable to apply it to the case of pressing with a crimping roller. The reason is that it is easy to apply a pressure to a direction other than the thickness direction of the film.

(The gap in the configuration of one packing layer is filled with another packing layer)

The omissions can be eliminated by forming a filler layer of the first filler layer and the second filler layer with a specific arrangement and a specific number density in the design, and then confirming the arrangement and number density of the fillers for the entire area to In accordance with the particle configuration of the conductive particle layer, another filler layer is formed by filling the gaps in the particle configuration of a filler layer as needed, and the filler of the entire film containing the filler such as an anisotropic conductive film is provided. For specific configurations. Therefore, the filler layer formed later can also change the number density in the longitudinal direction of the film containing the filler. As a result, the yield of the film containing the filler is improved, and the effect of cost reduction can be expected.

(Lamination of the second resin layer)

As shown in FIG. 11A, a filler-containing film such as an anisotropic conductive film may be used. The lowest melt viscosity at the surface area layer of one of the filler dispersion layers 3 is preferably lower than the second resin of the resin layer 2 forming the filler dispersion layer 3. Layer 4. In addition, the embedding rate 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 than the second filler layer, anisotropy as shown in FIG. 11B may be obtained. Films containing fillers, such as conductive films, are generally like the first filler layer side-laminated second resin layer 4, which has a large amount of protrusion from the resin layer 2. Alternatively, anisotropic conductive films such as those shown in FIG. 11C may be used 10G, the second resin layer 4 is the surface area layer of the resin layer 2 not protruding from the filler layer. By stacking the second resin layer 4, when an electronic component is anisotropically conductively connected using a film containing a filler such as an anisotropic conductive film, the space formed by the electrodes or bumps of the electronic component can be filled and lifted. Sex. When the second resin layer 4 is laminated, it is preferable that the second resin layer 4 is attached to an electronic component that is to be pressurized with a tool (the resin layer 2 is attached to an electronic component placed on a stage. ). This can prevent accidental movement of the filler and improve catchability.

Regarding the minimum melt viscosity of the resin layer 2 and the second resin layer 4, when there is a difference, the space formed by the electrodes or bumps of the electronic parts is easily filled with the second resin layer 4, and it is expected that the electronic parts will be improved to each other. The effect of sex. In addition, the larger the difference is, the smaller the amount of movement of the resin layer 2 existing in the filler dispersion layer 3 is, and therefore 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 even 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 made into a package, there is a risk of resin overflow or adhesion, so it is preferably 15 in practical use. the following. Regarding the preferable minimum melt viscosity of the second resin layer 4, more specifically, it satisfies the above-mentioned ratio and is 3000 Pa · s or less, more preferably 2000 Pa · s or less, and especially 100 to 2000 Pa · s.

The second resin layer 4 can be formed by adjusting the viscosity in the same resin composition as the resin layer.

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

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

(Lamination of the third resin layer)

A third resin layer may be provided on the side opposite to the second resin layer 4 through 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 melting viscosity of the anisotropic conductive film obtained by combining the resin layer 2, the second resin layer 4, and the third resin layer is not particularly limited, and is practically 8,000 Pa · s or less, preferably 200 to 7000 Pa · s or less. , Especially preferably 200 ~ 4000Pa‧s.

(Other laminated appearances)

Depending on the application of the film containing a filler, a plurality of filler dispersion layers 3 can be laminated, or a filler-free layer, such as a second resin layer, can be interposed between the filler dispersion layers of the laminate, and a second resin layer can be provided on the outermost layer Or the third resin layer.

<Manufacturing method of film containing filler>

The filler-containing film of the present invention having a single layer of the filler dispersion layer 3 as a resin layer can be obtained, for example, by keeping 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 using 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 of the resin layer 2. A surface. In addition, when the filler is held on both sides of the resin layer in a specific dispersion state, it can be attached by various methods, such as using a coating roller or a transfer mold. It is preferable to keep the filler on one surface of the resin layer. The orientation is reversed (180 degrees) from the direction that holds the filler on the other surface. Thereby, the unevenness of the dispersion state of the filler on the front side of the film and the unevenness of the dispersion state of the filler on the back side can be eased when the front and back are observed integrally.

Further, a film containing a filler such as an anisotropic conductive film in which the second resin layer 4 is laminated on the filler dispersion layer 3 can be obtained, for example, as shown in FIG. 12. That is, the filler 1A is adhered to one surface of the resin layer 2 (see FIG. A) and pressed (see FIG. B), and then the second resin layer 4 (see FIG. C) of the area layer into which the filler 1A is pressed. A filler 1B is attached to the surface of the resin layer 2 on the side opposite to the second resin layer 4 (see FIG. D), and the filler 1B is pressed into the resin layer 2 (see FIG. E). In this way, a filler-containing film 10 such as an anisotropic conductive film in which the second resin layer 4 is laminated on the filler dispersion layer 3 can be obtained. In this case, by appropriately setting the configuration of the fillers 1A pushed in from one surface of the resin layer 2 and the configuration of the fillers 1B pushed in from the other side, the fillers 1A, 1B are formed in contact with each other in a plan view. Or close to the filler unit 1C.

A filler-containing film such as an anisotropic conductive film in which the resin layer is formed of a single layer of the filler dispersion layer 3, and a filler-containing film such as an anisotropic conductive film in which the second resin layer 4 is laminated on the filler dispersion layer 3, and further Regarding the state in which the third resin layer is laminated, as a method of adhering the fillers 1A and 1B to the resin layer 2 or a method of forming the resin layer 2 in which the fillers 1A and 1B are dispersed, there can be cited: using a transfer mold to transfer the filler A method for printing onto a resin layer, a method for dispersing a filler in a resin layer, and a method of applying a resin liquid containing a filler to a resin using a coating roller having a regular groove on a surface, such as a gravure coater, as in the method described in Patent Document 1. Layer or peeling film, etc. Furthermore, in a method of applying a resin liquid containing a filler to a release film using a coating roller, the resin layer thus formed can be used as the resin layer 2. As described above, it is estimated that the method described in Patent Document 1 does not allow the fillers to be arranged regularly and accurately compared to the method using a transfer mold. However, in the present invention, the filler 1A forming the first filler layer and the second filler layer are formed. In the case where the filler 1B adheres in the long-side direction of the anisotropic conductive film, the filler is missing or the number density is not uniform even when the conductive particle layer is formed. 2 For the two filler layers, the missing or uneven number density of the fillers will not overlap, so that the missing or uneven number density of fillers in each filler layer will affect the conduction characteristics. reduce.

Among the above methods, a transfer mold is preferably used in terms of improving the accuracy of the arrangement of the fillers. As the transfer mold, for example, an opening can be formed in an inorganic material such as silicon, various ceramics, glass, stainless steel or the like, or an organic material such as various resins by a known opening forming method such as photolithography. The transfer mold may have a shape such as a plate shape or a roll shape.

Generally, in the step of using a transfer mold to attach a filler such as conductive particles to a resin layer, in order to manufacture a film containing a filler such as a long anisotropic conductive film, the conductive particles are sequentially moved from one end of the resin layer to the other end. It is attached in the direction, but as the attachment step of the filler continues, there is a tendency that the filler does not adhere to the resin layer due to the clogging of the mold, and in the film containing the filler such as an anisotropic conductive film, the place where the filler is missing increases. Therefore, when the filler that becomes the first filler layer is attached from one end to the other end of the resin layer, the filler that becomes the second filler layer is preferably attached from the other end of the resin layer to one end. By reversing the attachment direction in this way, the region with a higher probability of missing the conductive particles in the first filler layer becomes a region with a lower probability of missing the filler in the second filler layer, which can make the anisotropy The number density of the fillers in the whole film containing the filler such as conductive film is uniform, which can eliminate the excessive omission that affects the performance of the filler in the anisotropic conductive connection (in the case of anisotropic conductive film, it is a poor connection) ). In addition, a film containing a filler such as a long anisotropic conductive film is generally manufactured in the form of a roll. Therefore, it is preferable to manufacture the film by inverting the adhesion direction of the first filler layer and the second filler layer. First, while the filler that becomes the first filler layer is adhered from one end of the long resin layer to the other end, the resin layer is formed into a roll body, and then the roll body is rolled back, and the first The filler of the 2 filler layer is adhered to the resin layer in a direction reverse to the adhesion direction of the first filler layer, and the resin layer is made into a package. As a result, compared with rewinding the package body having the resin layer formed with the first filler layer and re-attaching the filler that becomes the second filler layer to the resin layer in the same attachment direction as the first filler layer, the step can be made Simplified, so the effect of cost reduction can be expected. Furthermore, when the attachment direction is reversed, the clogged transfer mold may be replaced with a new one if necessary, and cleaning may be performed. In the case where the missing product of the 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 a resin liquid containing conductive particles to a resin layer or a release film using a coating roller, as the coating continues, the groove on the surface of the coating roller will also be blocked, so the filler is preferably from the film. Apply the other end to one end.

Moreover, in the method of dispersing a filler in a resin layer, there may be a case where the defect of the filler is periodically repeated. In this case, it is also preferable that the filler-forming portion is located on the front and back of the resin layer so that the filler does not overlap. It is also preferred that the filler that becomes the first filler layer is attached to the resin layer, and When the filler of the second filler layer is adhered 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 manufacturing methods, in the case of manufacturing a film containing a filler such as a long anisotropic conductive film, it will inevitably form a missing part of the filler, but by using Reversing the attachment direction of the filler in the long-side direction of the filler-containing film such as the anisotropic conductive film of the first filler layer and the second filler layer allows the missing portion to be located in the filler-containing film such as the anisotropic conductive film. The film does not concentrate on one site, but disperses sites that are missing. Therefore, it can contribute to improvement of the yield of a film containing a filler, such as an anisotropic conductive film, or reduction of manufacturing cost.

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 or the like is used. The reversal of the adhesion direction of the first filler layer in the film containing the filler and the adhesion direction of the second filler layer is effective in reducing unevenness in the number density of the fillers in the filler-containing film such as an anisotropic conductive film. . For example, when designing a filler-containing film such as an anisotropic conductive film, the fillers are arranged in the same manner as the first filler layer and the second filler layer, and the number density is set to, for example, 400 particles / mm ² . In the above manufacturing method, the absolute value of the difference in number density between one end and the other end in the longitudinal direction of an anisotropic conductive film such as an anisotropic conductive film actually manufactured is preferably 160 pieces / mm ² or less, more preferably 80 particles / mm ² or less. Similarly, when the number density of the conductive particles in the first filler layer and the second filler layer is set to 65,000 particles / mm ² , respectively, the The absolute value of the difference between the number density at 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 long-side direction of a film containing a filler such as an anisotropic conductive film becomes the average of the number density of the conductive particles in the first filler layer and the second filler layer. That is, the range of 800 to 130,000 pieces / mm ² is preferably within a range of ± 20%, and more preferably within a range of ± 10%. Furthermore, the present invention does not exclude the case where the number density is less than 400 pieces / mm ² . The present invention is described using an anisotropic conductive film as an example, but the invention 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 a matting film or the like directly related to the appearance.

The filling amount of the fillers 1A and 1B attached to the resin layer 2 can be adjusted by the pressing pressure and temperature when the fillers 1A and 1B are pressed, and the presence, shape and depth of the depressions 2x and 2y can be adjusted by pressing. The viscosity, pressing speed, temperature, etc. of the resin layer 2 at the time of adjustment are adjusted. As a pressing method for making the embedding rate exceed 100%, a method of pressing using a pressing plate having convex portions corresponding to the arrangement of the filler may be mentioned.

Films containing a filler such as an anisotropic conductive film formed into a long strip are appropriately cut off, and are formed into a package body into a film containing a filler such as an anisotropic conductive film. Therefore, a film containing a filler such as the anisotropic conductive film of the present invention has a length of, for example, 5 to 5000 m, and can be formed into a package.

In order to economically connect electronic parts using an anisotropic conductive film included in a film containing a filler, the anisotropic conductive film is preferably a certain length. Therefore, the length of the anisotropic conductive film is preferably 5 m or more, more preferably 10 m or more, and even 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 an electronic component using the anisotropic conductive film cannot be used, and the operability is also poor. Therefore, the length of the anisotropic conductive film is preferably 5,000 m or less, more preferably 1000 m or less, and even more preferably 500 m or less. Such an elongated body of an anisotropic conductive film is preferably a package body wound around a core in terms of excellent operability.

<How to use filler-containing film>

The filler-containing film of the present invention can be used in the same manner as the conventional filler-containing film, and as long as a film containing a filler can be attached, there is no particular limitation on the article. Various articles corresponding to the use of the film containing a filler can be bonded by compression bonding, preferably by thermocompression bonding. During this bonding, light irradiation may be used, or heat and light may be used in combination. For example, in the case where the resin layer of the film containing the filler has sufficient adhesion to the article to which the film containing the filler is attached, it can be obtained by gently pressing the resin layer of the film containing the filler against the article. A film laminate in which a film of a filler is adhered to the surface of an article. In this case, the surface of the article is not limited to a flat surface, and may have unevenness or be curved as a whole. When the articles are film-like or flat-plate-like, a film containing a filler can be attached to these articles using a crimping roller. Thereby, the filler of the film containing the filler can be directly bonded to the article.

In addition, a film containing a filler may be interposed between the two objects facing each other, and the two objects facing each other may be joined by a hot-press bonding roll or a crimping tool, and the filler may be held between the objects. Moreover, the filler may not be in direct contact with the article, and the film containing the filler may be sandwiched by the article.

Especially when the film containing a filler is an anisotropic conductive film, the first electronic component such as an IC chip, an IC module, an FPC, and an FPC and glass are bonded through the anisotropic conductive film using a thermocompression bonding tool. The second electronic component such as a substrate, a plastic substrate, a rigid substrate, or a ceramic substrate is preferably used when anisotropic conductive connection is performed. An anisotropic conductive film can be used to stack and multiply IC chips or wafers. Furthermore, the electronic components connected by the anisotropic conductive film of the present invention are not limited to the above-mentioned electronic components. Can be used for various electronic parts diversified in recent years.

Therefore, the present invention includes a connection structure in which the film containing the filler of the present invention is bonded to various articles by compression bonding, or a method for manufacturing the same. In particular, when the film containing a filler is an anisotropic conductive film, it also includes a method of manufacturing a connection structure using the anisotropic conductive film to anisotropically conductively connect electronic parts to each other, or by this method. The obtained connection structure is a connection structure in which electronic components are anisotropically conductively connected to each other through the anisotropic conductive film of the present invention.

As a method for connecting electronic parts using an anisotropic conductive film, when the anisotropic conductive film is composed of a single layer of a conductive particle dispersion layer, it can be manufactured by: second electrons such as various substrates The component is temporarily attached and temporarily crimped from the side where the conductive particles are embedded on the surface of the anisotropic conductive film, and the first electronic component such as an IC chip is superimposed on the surface of the anisotropic conductive film that has been temporarily crimped. The side of the particle is thermocompression bonded. When the insulating resin layer of the anisotropic conductive film contains not only a thermal polymerization initiator and a thermally polymerizable compound but also a photopolymerization initiator and a photopolymerizable compound (which may be the same as the thermally polymerizable compound), A crimping method using light and heat together. If so, the accidental movement of the conductive particles can be suppressed to a minimum. In addition, the side where the conductive particles are not embedded may be temporarily attached to the second electronic component and used. The anisotropic conductive film may be temporarily attached to the first electronic component instead of the second electronic component.

In the case where the anisotropic conductive film is formed of a laminated body of a conductive particle dispersed layer and a second insulating resin layer, the conductive particle dispersed layer is temporarily attached to second electronic components such as various substrates and temporarily pressure-bonded. The first electronic component such as an IC chip is aligned and placed on the second insulating resin layer side of the anisotropic conductive film that has been temporarily pressure-bonded, 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. Alternatively, the conductive particle dispersion layer side may be temporarily attached to the first electronic component and used.

Examples

Hereinafter, an 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) Manufacturing of anisotropic conductive film

(1-1) Examples 1A and 1B to Example 8

Prepare (i) a high-viscosity first insulating resin layer (hereinafter, also referred to as layer A) and (ii) a viscosity lower than that of the first insulating resin layer at the mixing ratio shown in Table 1. The second insulating resin layer (hereinafter also referred to as N layer), and (iii) the resin composition of the third insulating resin layer forming the adhesive layer.

The resin composition forming the first insulating resin layer (layer A) was coated on a PET film having a film thickness of 50 μm with a bar coater, and dried in an oven at 80 ° C. for 5 minutes to form a surface on the PET film. An insulating resin layer having a thickness as shown in 2. Similarly, a second insulating resin layer (N layer) and a third insulating resin layer (adhesive layer) were formed on the PET film in the thicknesses shown in Table 3.

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 a plan view, and the areal density of the conductive particles is 800 as shown in Table 2 when used for FOG. / mm ² (Example 1A, 1B), or such as to be 10000,20000 or 30,000 / mm ² (Examples 2 to 8) in such manner when the manufacturing mold shown in table 3 with the COG. That is, a mold is produced so that the convex pattern of the mold is arranged in a square lattice, and the angle θ formed by the lattice axis and the short-side direction of the anisotropic conductive film becomes 15 °, and the particles of a known transparent resin are melted. The resin mold having flowed into the mold and cooled and solidified was formed into a roll shape by forming a resin mold having recesses in an arrangement pattern shown in FIG. 1A.

The concave portion of the resin mold was filled with conductive particles (Sekisui Chemical Industry Co., Ltd., AUL703, average particle diameter: 3 μm), and the first insulating resin layer (layer A) was covered thereon, and a pressure roller was used at 60 ° C., By pressing at 0.5 MPa, the conductive particles were bonded over a length of 300 m from one end to the other end of the first insulating resin layer. Then, the first insulating resin layer (layer A) was peeled 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 pressure roller (pressing conditions: 70 ° C, 0.5 MPa). The first insulating resin layer (layer A) forms a first conductive particle layer. The indentation rate was set to 100%, so that the conductive particles and the surface of the first insulating resin layer (layer A) were on the same plane. A depression is formed around a tangent plane of the first insulating resin layer on the center portion between the adjacent conductive particles, with respect to the surrounding conductive particles.

Next, the second insulating resin layer (N layer) was bonded to the surface of the first insulating resin layer (layer A) where the conductive particles were pressed by heat and pressure (45 ° C, 0.5 MPa), and the opposite side Conductive particles were adhered across a length of 300 m in the same manner as described above, and the conductive particles were pressed in to form a second conductive particle layer to obtain a conductive particle dispersion layer. In this case, the conductive particles (the first conductive particle layer) to be pressed in first and the conductive particles (the second conductive particle layer) to be pressed later are offset by 3 μm in the short-side direction of the film. The direction of movement of the first insulating resin layer to which the conductive particles are attached is reversed from the case where the first conductive particle layer is formed. When forming the second conductive particle layer, the indentation rate was also set to 100%, so that the conductive particles and the surface of the first insulating resin layer (layer A) became the same plane. A depression is formed around a tangent plane of the first insulating resin layer on the center portion between the adjacent conductive particles, with respect to the surrounding conductive particles.

In Examples 1A, 2, 3, 4, 6, 7, and 8, the conductive particle dispersion layer obtained in the above manner was used as an anisotropic conductive film. In Example 1B, the movement direction of the film when the conductive particles that became the first conductive particle layer were attached to the first insulating resin layer and the movement of the film when the conductive particles that became the second conductive particle layer were attached to the first insulating resin layer The direction is the same.

In Example 5, the third insulating resin layer (adhesiveness) was bonded to the surface of the conductive particle dispersion layer on the side opposite to the second insulating resin layer (N layer) by applying heat and pressure (45 ° C, 0.5 MPa). Floor).

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

(1-2) Comparative Examples 1 to 3

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

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

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

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

For the anisotropic conductive films of Comparative Examples 1 to 3, the variation tendency (increasing or decreasing tendency) of the number density of conductive particles from one end to the other end was also studied. The results are shown in Tables 2 and 3.

(2) Evaluation

The anisotropic conductive films of the examples and comparative examples produced in (1) were cut with a sufficient area for connection, and (a) the initial on-resistance and (b) the on-resistance after the reliability test were performed as follows , (C) Particle capture, (d) Short-circuit rate, (e) Temporary crimpability. The results are shown in Tables 2 and 3.

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

(a) Initial on-resistance

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

A sample of the anisotropic conductive film was sandwiched between the FPC for evaluation of the conduction characteristics and the glass substrate, and the tool width was 1.5 mm, followed by heating and pressing (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 1 Ω or less. Therefore, the initial on-resistance of 1 Ω or less is set to OK, and the case of exceeding 1 Ω is set to NG.

Here, regarding the FPC for evaluation and the glass substrate, the terminal patterns of these correspond to each other, and the dimensions are as follows. When the FPC for evaluation was connected to the glass substrate, the long-side direction of the anisotropic conductive film was aligned with the short-side direction of the terminal.

FPC for evaluation of conduction characteristics

Terminal pitch 50μm

Terminal width: interval between terminals = 1: 1

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

Glass base board

Electrode ITO coating

Thickness 0.7mm

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

A sample of the anisotropic conductive film was 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 each connection for evaluation. The on-resistance of the evaluation connector was measured. The initial on-resistance is practically preferably 1 Ω or less. Therefore, an initial on-resistance of 1 Ω or less is evaluated as OK, and a case where it exceeds 1 Ω is evaluated as NG.

Here, regarding the evaluation IC and the glass substrate, these terminal patterns correspond, and the dimensions are as follows. When the evaluation IC is connected to the glass substrate, the long-side direction of the anisotropic conductive film is aligned with the short-side direction of the bump.

IC for evaluation of conduction characteristics

1.8 × 20.0mm

0.5mm thickness

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

Glass base board

1737F made by Corning

30 × 50mm

0.5mm thickness

Electrode ITO wiring

(b) On-resistance after reliability test

The on-resistance after the connection for evaluation prepared in (a) was left in a thermostatic bath at a temperature of 85 ° C. and a humidity of 85% RH for 500 hours was measured in the same manner as the initial on-resistance. The on-resistance after the reliability test is practically less than 6Ω. Therefore, a value of 6 Ω or less is set to OK, and a case of more than 6 Ω is set to NG.

(c) Particle capture

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

In the connection for the evaluation of the conduction characteristics, the number of captured conductive particles was measured for 100 areas of 25 × 400 μm in the FPC terminals of the connection part, and the minimum number of captures was obtained, and evaluated according to the following criteria.

A (Good): 3 or more

B (no problem in practice): less than 3

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

Using the evaluation IC for particle capture, the evaluation IC was aligned with the glass substrate corresponding to the terminal pattern by 6 μm, and heated and pressurized (180 ° C, 80 MPa, 5 seconds). The captured number of conductive particles was measured in 100 6 μm × 66.6 μm areas where the terminals overlap, and the minimum captured number was obtained, and evaluated according to the following criteria. Practically, the B evaluation or more is preferred.

IC for particle trapping evaluation

1.6 × 29.8mm

0.3mm thickness

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

Particle Capture Evaluation Criteria

A (Good): 5 or more

B (no problem in practice): 3 or more and 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 and 1B)

The same FPC as the FPC for conducting characteristics evaluation was heated and pressurized (200 ° C, 5 MPa, 5 seconds) on an alkali-free glass (thickness 0.7 mm), and the number of short circuits of the obtained connection for evaluation was measured. The number of short-circuits measured and the number of gaps in the connection for evaluation were used to determine the short-circuit generation rate, and evaluated according to the following criteria.

A (good): less than 50 ppm

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

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, an evaluation connector was obtained in the same manner as in the evaluation of the initial on-resistance (a), and the number of short circuits of the obtained evaluation connector was measured. Based on the measured number of short circuits and The number of gaps in the connection for evaluation was used to calculate the short-circuit generation rate, and the evaluation was performed according to the following criteria.

IC for evaluation of short-circuit rate (comb-teeth TEG (test element group) at 7.5 μm interval)

15 × 13mm

0.5mm thickness

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

Short circuit rate evaluation criteria

A: Less than 50ppm

B: 50ppm or more and less than 200ppm

C: 200ppm or more

(e) Temporary crimpability

Using a crimping tool, press the anisotropic conductive film with PET film (width 1.5mm, length 50mm) against the ITO glass at a temperature of 60 ° C or 70 ° C, a crimping pressure of 1MPa, and a crimping time of 1 second. Crimp temporarily. In this case, a 350 μm-thick silicone rubber is interposed between the crimping tool and the PET film as a buffer material. The PET film was peeled off for 100 temporarily crimped samples obtained by pressing the anisotropic conductive film against the ITO glass in this manner. At this time, for the success of the temporary crimping, for the sake of convenience, it is determined that one of the anisotropic conductive film has not been peeled from the ITO glass together with the PET film, and it is determined that even if there is one peeling For NG.

A: OK above 60 ° C

B: OK above 70 ° C

C: NG above 70 ° C

As shown in Table 2, conductive particles are embedded on the front surface of the insulating resin layer at an embedding rate of 100%. From one end to the other end of the anisotropic conductive film, the number density of the conductive particles is Increasing or decreasing tendency In Example 1A where the first conductive particle layer and the second conductive particle layer are in opposite directions, on one end and the other end of the anisotropic conductive film, on-resistance, on-resistance reliability, and particle capture rate All of them were rated good, short circuit rate, and temporary crimpability. In contrast, in Example 1B where the first conductive particle layer and the second conductive particle layer coincide with each other, the number density of the number density of the conductive particles in the first conductive particle layer and the second conductive particle layer is the same. The lower part of the film has a part with poor particle trapping properties, and the other end of the film with a higher number density has obtained a good evaluation including particle trapping properties. Moreover, in this evaluation, since the connection area is sufficient, it is judged that there is no practical problem even if it is a B evaluation of less than three.

As shown in Table 3, the anisotropic conductive films of Examples 2 to 8 were also embedded with conductive particles at the embedding rate of 100% on the front and back surfaces of the insulating resin layer, and the long-side direction of the anisotropic conductive film The increase or decrease in the number density of the conductive particles on the surface tends to be in the opposite direction in the first conductive particle layer and the second conductive particle layer, which is good in any evaluation item. In particular, according to Example 2 and Example 5, it can be seen that the anisotropic conductive film of the present invention has good temporary adhesion, excellent workability, and excellent particle trapping properties even without an adhesive layer.

In addition, from Comparative Example 1, it was found that if the conductive particles were monodispersed in the conductive particle dispersion layer, both the particle trapping property and the short-circuit rate were inferior. From Comparative Example 2, it can be seen that if the conductive particle layer is formed only on the second insulating resin layer (N layer) side, the particle trapping property is poor; from Comparative Example 3, it can be seen that if the conductive particle layer is formed only from the second insulation On the opposite side of the resin layer (N layer), the temporary crimpability is poor. Furthermore, in Comparative Example 3, if the temporary compression bonding temperature was set to 75 ° C, the anisotropic conductive film was not peeled from the ITO glass even if the number of temporary compression bonding samples was set to 500. Therefore, it can be confirmed that Comparative Example 3 is based on The setting of the temporary crimping temperature can be used for practical use.

(3) Transfer rate

Regarding the anisotropic conductive film of Example 1, the transfer rate of the conductive particles when the first conductive particle layer was formed (first time) and the transfer of the conductive particles when the second conductive particle layer was formed (second time). The print rate is measured.

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

The transfer rate is measured using a metal microscope to measure the number of conductive particles in the first conductive particle layer or the second conductive particle layer existing in an anisotropic conductive film with an area of 1 mm ² in lengths of 0 m, 50 m, 100 m, 200 m, and 300 m. Calculate the average. The first conductive particle layer (first time) is formed by transferring conductive particles from the 0m side to the 300m side of the anisotropic conductive film, and the second conductive particle layer (second time) is formed by It is formed by transferring 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 total transfer rate 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 (17)

    A filler-containing film includes a resin layer and a filler dispersion layer. The filler dispersion layer includes a first filler layer composed of a filler dispersed in the resin layer in a single layer, and a second filler layer composed of The depth different from the first filler layer is composed of a single layer of fillers dispersed in the resin layer; and the filler of the first filler layer is exposed from one surface of the resin layer, or is close to the one surface, and the filler of the second filler layer It is exposed from or close to the other surface of the resin layer.         For example, the film containing a filler in item 1 of the scope of patent application, wherein the ratio of the layer thickness (La) of the resin layer to the average particle diameter D of the filler (La / D) is 0.6 to 10.         For example, the film containing a filler in item 1 or 2 of the scope of patent application, wherein, in the longitudinal direction of the film containing the filler, one of the number density of the fillers of the first filler layer and the number density of the fillers of the second filler layer One gradually increases and the other gradually decreases.         For example, if the filler-containing film according to any one of the claims 1 to 3 is applied, the filler units in which the fillers of the first filler layer or the fillers of the second filler layer are in contact with or close to each other, and the filler units are not Contact and the packing units are regularly arranged.         For example, if the filler-containing film according to any one of the claims 1 to 3 is applied, the filler unit formed by the filler of the first filler layer and the filler of the second filler layer is in contact with each other, and the filler units are not in contact with each other. And the packing units are regularly arranged.         For example, the film containing a filler in item 4 of the patent application scope, wherein, in a plan view, 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.         For example, the filler-containing film according to any one of claims 1 to 6, wherein the filler dispersion layer is laminated with the second resin, and the minimum melt viscosity of the second resin layer is lower than that of the resin layer forming the filler dispersion layer.         For example, the filler-containing film according to any of claims 1 to 7, wherein the surface of the resin layer near the filler has a slope or undulation with respect to the tangent plane of the resin layer on the central portion between adjacent fillers. In the tilt, the surface of the resin layer surrounding the filler is defective with respect to the above-mentioned tangent plane. In the undulation, the amount of resin in the resin layer directly above the filler is less than when the surface of the resin layer directly above the filler is in the above-mentioned tangent plane.         For example, the filler-containing film according to any one of claims 1 to 8 in the application, wherein the filler is conductive particles, the resin layer is an insulating resin layer, and the film containing the filler is used as an anisotropic conductive film.         A method for manufacturing a film containing a filler, which is a method for manufacturing a film containing a filler according to any one of claims 1 to 8 of the scope of application for a patent, and wherein: the filler is maintained on a surface of a resin layer in a specific dispersion 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 dispersion state, and the filler is pressed into the resin layer.         A method for manufacturing a film containing a filler, which is a method for manufacturing a film containing a filler according to any one of claims 1 to 8. In the film containing a filler, the filler is conductive particles and the resin layer is an insulating resin. Layer, and the film containing the filler is used as an anisotropic conductive film, and the manufacturing method is: maintaining the filler in a specific dispersed state on one surface of the resin layer, and pressing the filler into the resin layer, and making other The filler is held on the other surface of the resin layer in a specific dispersion state, and the filler is pressed into the resin layer.         For example, the method for manufacturing a film containing a filler in the scope of the patent application No. 10 or 11, wherein when the filler is maintained in a specific dispersion state on both sides of the resin layer, the direction of holding the filler in one surface of the resin layer is different from that in another The direction of holding the filler in one surface is reversed.         A film bonding body is used for bonding a film containing a filler according to any one of claims 1 to 9 to an article.         A connection structure in which a first article and a second article are connected via a filler-containing film according to any one of claims 1 to 9.         For example, the connection structure of the scope of application of the patent No. 14 is an anisotropic conductive connection between the first electronic component and the second electronic component through the film containing the filler of the scope of the patent application No. 9.         A method for manufacturing a connection structure, wherein a first article and a second article are pressure-bonded via a film containing a filler according to any one of claims 1 to 9.         For example, the manufacturing method of the connection structure of the scope of the patent application No. 15 sets the first article and the second article as the first electronic part and the second electronic part, respectively. The film is a connection structure in which the first electronic component and the second electronic component are thermocompression bonded to produce an anisotropic conductive connection between the first electronic component and the second electronic component.