JP6705442B2 - Method for manufacturing connection structure - Google Patents

Description

The present invention relates to a method for manufacturing a connection structure.

When manufacturing a connection structure by connecting a substrate such as a glass panel for liquid crystal display and a circuit component such as an IC for driving liquid crystal, an anisotropic conductive film in which conductive particles are dispersed in an adhesive layer is used. There are cases. In this case, it is possible to collectively connect the plurality of protruding electrodes provided on the circuit component to the substrate.

In recent years, with the development of electronic devices, the density of wirings and the functionality of circuits have been increasing. As a result, the area and pitch of the protruding electrodes are reduced. In order to obtain a stable electrical connection in such connection of the protruding electrodes, it is necessary to interpose a sufficient number of conductive particles between the protruding electrodes and the substrate.

To address such a problem, for example, Patent Document 1 discloses a method for manufacturing a connection structure using an anisotropic conductive film in which conductive particles are present near one surface of the anisotropic conductive film.

JP, 2007-103545, A

However, even when the conventional anisotropic conductive film described above is used, the adhesive component of the anisotropic conductive film flows when the connection structure is manufactured by heating and pressurizing, and the conductive particles May flow out between the protruding electrode and the substrate. In this case, a sufficient number of conductive particles may not be present between the protruding electrode and the substrate.

The present invention has been made to solve the above problems, and an object thereof is to provide a method for manufacturing a connection structure capable of interposing a sufficient number of conductive particles between a protruding electrode and a substrate. And

To solve the above problems, the method for manufacturing a connection structure according to the present invention is a circuit component having a protruding electrode and a substrate, through an anisotropic conductive film in which conductive particles are dispersed in an adhesive layer. A method of manufacturing a connection structure comprising a connecting step of connecting, wherein the anisotropic conductive film is an anisotropic conductive film in which conductive particles are unevenly distributed on one side of the anisotropic conductive film, and the connecting step is one side. An anisotropic conductive film is arranged between the circuit component and the substrate so that the side faces the substrate side, and the distance between the surface of the protruding electrode and the surface of the substrate is 150% or less of the average particle diameter of the conductive particles. As described above, the step of temporarily fixing the protruding electrodes into the anisotropic conductive film is provided.

In the method for manufacturing the connection structure, by pushing the protruding electrode into the anisotropic conductive film so that the distance between the surface of the protruding electrode and the surface of the substrate is 150% or less of the average particle diameter of the conductive particles, The adhesive component of the anisotropic conductive film can be removed in advance from between the protruding electrode and the substrate. As a result, the adhesive component existing between the protruding electrode and the substrate is reduced, so that even if the adhesive component flows due to the heating and pressurization in the subsequent main fixing step, the conductive particles may be separated from the protruding electrode and the substrate. It is possible to suppress the outflow from the space. Therefore, the conductive particles can be favorably trapped between the protruding electrode and the substrate, so that in the obtained connection structure, a sufficient number of conductive particles can be interposed between the protruding electrode and the substrate.

In the temporary fixing step, the protruding electrodes can be pressed into the anisotropic conductive film so that the distance between the surface of the protruding electrodes and the surface of the substrate is 100% or less of the average particle diameter of the conductive particles. In this case, since the conductive particles are temporarily fixed in contact with the protruding electrode and the substrate, the conductive particles can be more suitably captured between the protruding electrode and the substrate.

In the temporary fixing step, the protruding electrodes can be pressed into the anisotropic conductive film such that the distance between the surface of the protruding electrodes and the surface of the substrate is less than 100% of the average particle diameter of the conductive particles. In this case, in the temporary fixing step, the conductive particles are captured by meshing between the protruding electrode and the substrate, so that the outflow of the conductive particles due to the flow of the adhesive component of the anisotropic conductive film is further suppressed, and the conductive particles are electrically conductive. The particles can be more preferably trapped between the protruding electrode and the substrate.

The connecting step further includes a main fixing step of electrically connecting the protruding electrode and the substrate through the conductive particles by heating and further pushing the protruding electrode into the anisotropic conductive film after the temporary fixing step. You can In this case, since the adhesive component is previously removed from between the protruding electrode and the substrate in the temporary fixing step, even if the protruding electrode is further pressed into the anisotropic conductive film while the heating is performed in the main fixing step, the conductive particles are projected. It is possible to suppress the outflow between the electrode and the substrate, and it is possible to suitably capture the conductive particles between the protruding electrode and the substrate. Therefore, in the connection structure, a sufficient number of conductive particles can be interposed between the protruding electrode and the substrate.

According to the present invention, it is possible to interpose a sufficient number of conductive particles between the protruding electrode and the substrate.

It is a top view which shows the electronic device to which the connection structure which concerns on embodiment of this invention is applied. It is a top view which shows the connection structure of FIG. It is a schematic cross section which shows the II cross section in FIG. It is a schematic cross section which shows the temporary fixing process in the manufacturing method of the connection structure of FIG. It is a principal part expanded schematic cross section of FIG.4(b). It is a schematic cross section which shows the following main fixing process of FIG.

Hereinafter, an embodiment of a method for manufacturing a connection structure of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing an electronic device to which a connection structure according to an embodiment of the present invention is applied. As shown in FIG. 1, the connection structure 1 is applied to an electronic device 2 such as a touch panel. The electronic device 2 is composed of, for example, a liquid crystal panel 3 and a circuit component 4.

The liquid crystal panel 3 has, for example, a substrate 5 and a liquid crystal display unit 6. The substrate 5 has, for example, a rectangular plate shape having a size of 20 to 300 mm×20 to 400 mm and a thickness of 0.1 to 0.3 mm. As the substrate 5, for example, a glass substrate made of non-alkali glass or the like is used. Circuit electrodes (not shown) are formed on the surface 5 a of the substrate 5 so as to correspond to the liquid crystal display portion 6 and the protruding electrodes 42 (described later) of the circuit component 4. The liquid crystal display unit 6 is attached to the surface 5a of the substrate 5 and is connected to the circuit electrodes described above.

The circuit component 4 has a rectangular plate shape smaller than the substrate 5, and has a size of, for example, 0.6 to 3.0 mm×10 to 50 mm, for example, a thickness of 0.1 to 0.3 mm. The circuit component 4 is arranged apart from the liquid crystal display unit 6 and is connected to the circuit electrodes of the substrate 5 described above (details will be described later).

FIG. 2 is a plan view showing the connection structure. As shown in FIG. 2, the circuit component 4 has a main body 41 and a protruding electrode 42 provided on the main body 41. The main body 41 has a mounting surface 41a and a non-mounting surface 41b on the opposite side of the mounting surface 41a. In the connection structure 1, the circuit component 4 is arranged so that the substrate 5 and the mounting surface 41a face each other. A plurality of protruding electrodes (for example, bump electrodes) 42 protruding from the mounting surface 41 a are formed on the main body portion 41. Silicon or the like is used as a material for forming the main body portion 41 of the circuit component 4. The protruding electrode 42 is formed of a material (Au or the like) that is softer than the conductive particles (details will be described later) contained in the anisotropic conductive film.

As shown in FIG. 2, on the mounting surface 41a, for example, a plurality of protruding electrodes 42 are arranged in one row at substantially equal intervals along one long side 41c of the mounting surface 41a. Along the other long side 41d of 41a, a plurality of protruding electrodes 42 are arranged in three rows at substantially equal intervals in a zigzag shape. The one row of the protruding electrodes 42 arranged on the one long side 41c side is, for example, an input side electrode, and the three rows of the protruding electrodes 42 arranged on the other long side 41d side is, for example, an output side electrode. The protruding electrode 42 has a height of 2 to 15 μm (height from the mounting surface 41a), for example. In addition, in the mounting surface 41a, the plurality of protruding electrodes 42 may be arranged along, for example, 2 to 4 rows along one long side 41c, and the plurality of protruding electrodes 42 along the other long side 41d. May be arranged, for example, in 2 or 4 rows.

3 is a schematic cross-sectional view showing a cross section taken along the line I-I in FIG. As shown in FIG. 3, in the connection structure 1, the circuit component 4 and the substrate 5 are connected to each other through the anisotropic conductive film 9 in which the conductive particles 7 are dispersed in the adhesive layer 8. ..

As the adhesive component constituting the adhesive layer 8 of the anisotropic conductive film 9, a material curable by heat or light can be widely applied, and for example, an epoxy adhesive or an acrylic adhesive can be used. A crosslinkable material is preferably used because it has excellent heat resistance and moisture resistance after connection. Among them, an epoxy adhesive containing a thermosetting epoxy resin as a main component is preferably used from the viewpoint that it can be cured in a short time, has good connection workability, and has excellent adhesiveness. ..

Specific examples of epoxy adhesives include high molecular weight epoxy resins, solid epoxy resins or liquid epoxy resins, or these epoxy resins modified with urethane, polyester, acrylic rubber, nitrile rubber (NBR), synthetic linear polyamide, etc. An adhesive containing the modified epoxy resin as a main component is mentioned. The epoxy adhesive generally contains the above-mentioned epoxy resin as a main component and a curing agent, a catalyst, a coupling agent, a filler and the like.

As a specific example of the acrylic adhesive, an adhesive containing an acrylic resin (polymer or copolymer) containing at least one of acrylic acid, acrylic ester, methacrylic acid ester and acrylonitrile as a monomer component as a main component is used. Can be mentioned.

Examples of the conductive particles 7 contained in the anisotropic conductive film 9 include particles formed of Au, Ag, Pt, Ni, Cu, W, Sb, Sn, a metal such as solder, and conductive carbon. .. The conductive particles 7 may be coated particles in which particles formed of non-conductive glass, ceramics, plastics or the like are used as cores, and the cores are covered with the above metals, conductive carbon, or the like. Examples of the shape of the conductive particles 7 before connection include a substantially spherical shape and a shape in which a plurality of protrusions protrude in the radial direction (star shape).

From the viewpoint of dispersibility and conductivity, the average particle diameter of the conductive particles 7 before connection is preferably 1 to 18 μm, and more preferably 2 to 4 μm. Within this range, it is preferable to use conductive particles having an average particle size larger than the height of the protruding electrodes 42, but it is also possible to use conductive particles having an average particle size of, for example, 80 to 100% of the height of the protruding electrodes 42. Is. The average particle size of the conductive particles 7 can be obtained by measuring the particle size of 300 arbitrary conductive particles by observing with a scanning electron microscope (SEM) and taking the average value thereof. When the conductive particles 7 are not spherical such as having protrusions, the particle size of the conductive particles 7 may be the diameter of the circle circumscribing the conductive particles in the SEM image.

Then, the manufacturing method of the connection structure concerning this embodiment is explained. The method for manufacturing the connection structure according to the present embodiment includes a connecting step, and the connecting step includes a temporary fixing step and a main fixing step. FIG. 4 is a schematic cross-sectional view showing a temporary fixing step in the method for manufacturing the connection structure. In the temporary fixing step, as shown in FIG. 4A, as the anisotropic conductive film 9, an anisotropic conductive film in which conductive particles 7 are unevenly distributed on one surface 9a side of the anisotropic conductive film 9 is used. The anisotropic conductive film 9 is arranged between the circuit component 4 and the substrate 5 (on the surface 5a of the substrate 5) so that the one surface 9a side of the conductive film 9 faces the substrate 5 side.

The thickness of the anisotropic conductive film 9 may be, for example, 5 μm to 30 μm. The conductive particles 7 have a distance from the one surface 9a side of the anisotropic conductive film 9 that is preferably 150% or less of the average particle diameter of the conductive particles 7, more preferably 130% or less, and further preferably. It is located only in the range of 110% or less.

In the anisotropic conductive film 9, the method of unevenly distributing the conductive particles 7 on the one surface 9a side of the anisotropic conductive film 9 is not particularly limited. For example, the anisotropic conductive film in which the conductive particles 7 are unevenly distributed on the one surface 9a side of the anisotropic conductive film 9 is a conductive film containing the conductive particles 7 on one surface side of the insulating adhesive layer that does not contain the conductive particles 7. It is formed by stacking adhesive layers. In this case, the thickness of the conductive adhesive layer is preferably 0.6 times or more and less than 1.0 times the average particle size of the conductive particles 7, for example.

The content of the conductive particles 7 in the anisotropic conductive film 9 is 100 parts by volume of the components other than the conductive particles 7 in the anisotropic conductive film 9 from the viewpoint of preventing a short circuit due to excessive presence of the conductive particles 7. On the other hand, it is preferably 1 part by volume to 100 parts by volume, more preferably 10 parts by volume to 50 parts by volume. Particle density of the conductive particles 7 in the anisotropic conductive film 9, for example, 5000 / mm ² or more 50000 / mm ² may be less.

In the temporary fixing process, subsequently, as shown in FIG. 4B, the circuit component 4 is heated and pressed in the direction in which the circuit component 4 and the substrate 5 face each other (the arrow direction in FIG. 4B). The protruding electrode 42 of is pushed into the anisotropic conductive film 9. The heating temperature and pressure at this time are such that the adhesive component of the anisotropic conductive film 9 is made to flow while the conductive particles 7 are held without flowing out between the protruding electrodes 42 and the substrate 5. It is preferably a pressure, which is equal to or lower than the heating temperature and pressure in the subsequent main fixing step. Specifically, the heating temperature is, for example, 40° C. to 100° C., and the pressure is, for example, 2 MPa to 10 MPa per total electrode area of the protruding electrodes 42 of the circuit component 4.

FIG. 5 is an enlarged schematic cross-sectional view of a main part of FIG. As shown in FIG. 5, in the temporary fixing step, the distance d between the surface 42a of the protruding electrode 42 and the surface 5a of the substrate 5 is preferably 150% or less with respect to the average particle diameter of the conductive particles 7, The protrusion electrodes 42 of the circuit component 4 are pushed into the anisotropic conductive film 9 so that the protrusion electrode 42 is preferably 120% or less, more preferably 100% or less, and particularly preferably less than 100%. On the other hand, the distance d may be, for example, 0.4 times (40%) or more the average particle diameter of the conductive particles 7. By setting the distance d as described above, good connection reliability can be obtained in the connection structure after the main fixing step described later. The distance d between the surface 42a of the protruding electrode 42 and the surface 5a of the substrate 5 is determined by observing the temporarily fixed circuit component 4 and the substrate 5 from the substrate 5 side using, for example, a metal microscope, It can be calculated from the difference between the focal length of the surface and the focal length of the surface 5a of the substrate 5.

In the method for manufacturing the connection structure according to the present embodiment, the temporary fixing step is followed by the main fixing step. FIG. 6 is a schematic cross-sectional view showing the main fixing step. As shown in FIG. 6, in the main fixing step, the circuit component 4, the substrate 5, and the anisotropic conductive film 9 are heated and pressure is applied in the direction in which the circuit component 4 and the substrate 5 face each other (the arrow direction in FIG. 6). Thus, the protruding electrode 42 of the circuit component 4 is further pushed into the anisotropic conductive film 9. The heating temperature and pressure at this time are equal to or higher than the heating temperature and pressure in the above-mentioned temporary fixing step. Specifically, the heating temperature is, for example, 100° C. to 200° C., and the pressure is, for example, 20 MPa to 100 MPa per total surface electrode of the protruding electrodes 42 of the circuit component 4.

As a result, the adhesive component of the anisotropic conductive film 9 further flows, and the distance d between the surface 42a of the protruding electrode 42 and the surface 5a of the substrate 5 is further reduced. As a result, the flatness of the conductive particles 7 is, for example, 30% or more, and the connection between the circuit component 4 and the substrate 5 is secured. Then, by curing the adhesive layer 8 in a state where the conductive particles 7 are meshed between the protruding electrodes 42 and the substrate 5, the protruding electrodes 42 and the corresponding circuit electrodes (not shown) of the substrate 5 are electrically conductive particles. The connection structure 1 shown in FIG. 3 is obtained in a state in which the protruding electrodes 42 and 43 adjacent to each other and the circuit electrodes adjacent to each other are electrically connected via 7 and are electrically insulated from each other. If the adhesive component of the anisotropic conductive film 9 contains a photocurable resin, it is necessary to cure the adhesive layer 8 by heating and pressurizing and irradiating, for example, ultraviolet light in the main fixing step. Good.

In the method for manufacturing the connection structure, in the temporary fixing step, the distance d between the surface 42a of the protruding electrode 42 and the surface 5a of the substrate 5 is set to 150% or less of the average particle diameter of the conductive particles, so that the protruding electrode 42 is Is previously pushed into the anisotropic conductive film 9, and then the protruding electrode 42 is further pushed into the anisotropic conductive film 9 in the main fixing step. Here, in the conventional method for manufacturing a connection structure in which the main fixing step is performed without performing the temporary fixing step, the adhesive component of the anisotropic conductive film flows at once in the main fixing step. Therefore, the conductive particles may flow out from between the protruding electrode and the substrate due to the rapid flow of the adhesive component, and a sufficient number of conductive particles may not be present between the protruding electrode and the substrate.

On the other hand, in the method for manufacturing the connection structure, the adhesive component of the anisotropic conductive film 9 can be eliminated in advance from between the protruding electrode 42 and the substrate 5 by performing the temporary fixing step. As a result, the amount of the adhesive component existing between the protruding electrode 42 and the substrate 5 is reduced, so that even if the adhesive component flows due to the heating and pressurization in the subsequent main fixing step, the conductive particles 7 will not stick to the protruding electrode 42. It is possible to suppress the outflow from between the substrate 5 and the substrate 5. Therefore, the conductive particles 7 are favorably trapped between the protruding electrodes 42 and the substrate 5, so that in the resulting connection structure 1, a sufficient number of the conductive particles 7 are interposed between the protruding electrodes 42 and the substrate 5. It is possible to

The above-described effects are remarkably exhibited when the anisotropic conductive film 9 is an anisotropic conductive film in which the conductive particles 7 are unevenly distributed on the one surface 9a side of the anisotropic conductive film 9. The reason for this is that, from the viewpoint of fluidity of the fluid, the fluidity of the adhesive component on the interface side (on the one surface 9a side) of the anisotropically conductive film 9 with the substrate 5 is different from that at the central portion of the anisotropically conductive film 9. It may be lower than the fluidity of the adhesive component. For this reason, the conductive particles 7 having a low fluidity and unevenly distributed on the one surface 9a side are more suppressed in flow than the conductive particles 7 arranged in the entire anisotropic conductive film, so that the above-described effects are remarkably exhibited. it is conceivable that.

Further, in the temporary fixing step, the projection electrode 42 is made of an anisotropic conductive film so that the distance d between the surface 42a of the projection electrode 42 and the surface 5a of the substrate 5 is 100% or less of the average particle diameter of the conductive particles 7. When the conductive particles 7 are pushed into 9, the conductive particles 7 are temporarily fixed while being in contact with the protruding electrodes 42 and the substrate 5, so that the conductive particles 7 can be more suitably captured between the protruding electrodes 42 and the substrate 5.

Further, in the temporary fixing step, the projection electrode 42 is made of an anisotropic conductive film so that the distance d between the surface 42a of the projection electrode 42 and the surface 5a of the substrate 5 is less than 100% of the average particle diameter of the conductive particles 7. In the case of being pushed into 9, the conductive particles 7 are caught and caught between the protruding electrodes 42 and the substrate 5 in the temporary fixing step, so that the conductive particles 7 flow out as the adhesive component of the anisotropic conductive film 9 flows. Is further suppressed, and the conductive particles 7 can be more suitably captured between the protruding electrode 42 and the substrate 5.

Hereinafter, the present invention will be described more specifically based on Examples, but the present invention is not limited to these Examples.

[Examples 1-1 to 1-3, Comparative example 1-1]
(Synthesis of phenoxy resin a)
45 g of 4,4′-(9-fluorenylidene)-diphenol (manufactured by Sigma-Aldrich Japan Co., Ltd.) and 50 g of 3,3′,5,5′-tetramethylbiphenol diglycidyl ether (manufactured by Mitsubishi Chemical Corporation: YX- 4000 H) was dissolved in 1000 mL of N-methylpyrrolidone in a 3000 mL three-necked flask equipped with a Dimroth condenser, a calcium chloride tube, and a Teflon (registered trademark) stirring rod connected to a stirring motor to obtain a reaction solution. .. 21 g of potassium carbonate was added thereto, and the mixture was stirred while being heated to 110° C. with a mantle heater. After stirring for 3 hours, the reaction solution was added dropwise to a beaker containing 1000 mL of methanol, and the formed precipitate was collected by suction filtration. The precipitate collected by filtration was washed 3 times with 300 mL of methanol to obtain 75 g of phenoxy resin a.

After that, the molecular weight of the phenoxy resin a was measured using a high performance liquid chromatograph GP8020 manufactured by Tosoh Corporation (measurement conditions are as described above). As a result, Mn was 15769, Mw was 38045, and Mw/Mn was 2.413 in terms of polystyrene.

(Production of anisotropic conductive film A)
When forming the adhesive paste for the conductive adhesive layer, bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation: jER828) is used as an epoxy compound in a solid content of 50 parts by mass, and 4-hydroxyphenylmethylbenzyl sulfonium hexam is used as a curing agent. 5 parts by mass of fluoroantimonate in a solid content and 50 parts by mass of a phenoxy resin a as a film forming material in a solid content were blended. Further, as a conductive particle, a nickel layer having a thickness of 0.2 μm is provided on the surface of a particle having polystyrene as a nucleus, and a conductive particle having an average particle diameter of 3.3 μm and a specific gravity of 2.5 is produced. Was further blended into the above formulation. Then, this adhesive paste was applied to a PET film having a thickness of 50 μm using a coater and dried to obtain a conductive adhesive layer having a thickness of 3 μm formed on the PET film.

Next, in forming the adhesive paste for the insulating adhesive layer, bisphenol F type epoxy resin (manufactured by Mitsubishi Chemical Corporation: jER807) is used as an epoxy compound in a solid content of 45 parts by mass, and 4-hydroxyphenylmethyl is used as a curing agent. 5 parts by mass of benzylsulfonium hexafluoroantimonate in solid content and 55 parts by mass of bisphenol A/bisphenol F copolymer type phenoxy resin (Nippon Steel & Sumikin Chemical Co., Ltd.: YP-70) in solid content as a film forming material. did. Then, this adhesive paste was applied to a PET film having a thickness of 50 μm using a coater and dried to obtain an insulating adhesive layer having a thickness of 14 μm formed on the PET film. After that, the conductive adhesive layer and the insulating adhesive layer were heated to 40° C. and bonded with a hot roll laminator to obtain an anisotropic conductive film A sandwiched between PET films.

Regarding the obtained anisotropic conductive film A, the number of conductive particles per 25000 μm ² was measured at 20 locations, and the average value was converted to the number of conductive particles per 1 mm ² . As a result, the density of the conductive particles in the anisotropic conductive film A was 280000 particles/mm ² .

(Preparation of connection structure)
As a circuit component, prepare an IC chip with bump electrodes arranged (outer shape 2 mm x 20 mm, thickness 0.3 mm, bump electrode area 840 μm ² (length 70 μm x width 12 μm), space between bump electrodes 12 μm, bump electrode height 15 μm) did. A glass substrate (#1737, Corning, 38 mm×28 mm, thickness 0.3 mm) having an ITO wiring pattern (pattern width 31 μm, interelectrode space 7 μm) formed on the surface was prepared as a substrate.

A thermocompression bonding device including a stage (150 mm×150 mm) made of a ceramic heater and a tool (3 mm×20 mm) was used for connecting the IC chip and the glass substrate. Then, the PET film on the conductive adhesive layer side of the above anisotropic conductive film A (2.5 mm×25 mm) is peeled off, and heated and pressed for 2 seconds at 80° C. and 0.98 MPa for conductive adhesion. The surface on the agent layer side was attached to a glass substrate.

Next, after the bump electrodes of the IC chip and the circuit electrodes of the glass substrate are aligned with each other, the bump electrodes of the IC chip are changed by heating and pressing for 1 second at the temporary fixing temperature and the temporary fixing pressure shown in Table 1. It was pressed into the conductive film A. Table 1 shows the distance between the glass substrate and the bump electrode after the temporary fixing. The distance between the temporarily fixed substrate and the bump electrode was calculated from the difference between the focal length of the surface of the glass substrate and the focal length of the surface of the bump electrode by observing from the glass substrate side using a metallurgical microscope. ..

Then, the IC chip was finally fixed to the glass substrate by heating and pressurizing for 5 seconds under the conditions of 160° C. and 70 MPa to obtain a connection structure. The capture rate of the conductive particles in the connection structure was calculated based on the following formula.
Capture rate (%)=(number of conductive particles on bump electrode/(1 mm ² /bump electrode area)/number of conductive particles per 1 mm ² of anisotropic conductive film)×100
The number of conductive particles was measured at 200 bump electrodes using a metallurgical microscope, and the average value was used as the number of conductive particles on the bump electrodes. The results are shown in Table 1.

[Examples 2-1 and 2-2, Comparative Example 2-1]
(Preparation of anisotropic conductive film B)
Instead of phenoxy resin a, bisphenol A phenoxy resin (Nippon Steel & Sumikin Chemical Co., Ltd.: YP-50), bisphenol A/bisphenol F copolymerization phenoxy resin (Nippon Steel & Sumikin Chemical Co., Ltd.: YP-70), bisphenol An anisotropic conductive film B was produced in the same manner as the anisotropic conductive film A, except that the F-type phenoxy resin (FX-316 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) was used. Regarding the obtained anisotropic conductive film B, the number of conductive particles per 25,000 μm ² was measured at 20 locations, and the average value was converted to the number of conductive particles per 1 mm ² . As a result, the density of the conductive particles in the anisotropic conductive film B was 330000 particles/mm ² .

A connection structure was prepared under the conditions shown in Table 2 in the same manner as in Example 1-1 except that the anisotropic conductive film B was used, and the capture rate of the conductive particles was measured. The results are shown in Table 2.

[Examples 3-1 to 3-2, Comparative Examples 3-1 to 3-2]
A connection structure was prepared under the conditions shown in Table 3 in the same manner as in Example 1-1 except that the thickness of the insulating adhesive layer was changed as shown in Table 3, and the capture rate of the conductive particles was measured. .. The results are shown in Table 3.

[Examples 3-1 to 3-2, Comparative Examples 3-1 to 3-2]
A connection structure was prepared under the conditions shown in Table 4 in the same manner as in Example 1-1, except that the thickness of the insulating adhesive layer and the height of the bump electrode were changed as shown in Table 4. The capture rate was measured. The results are shown in Table 4.

[Reference Examples 1-1 to 1-3]
Connection structure under the conditions shown in Table 5 in the same manner as in Example 1-1, except that the thicknesses of the insulating adhesive layer and the conductive adhesive layer and the particle density of the conductive particles were changed as shown in Table 5. Was prepared and the capture rate of the conductive particles was measured. The results are shown in Table 5. In Reference Examples 1-1 to 1-3, while the conductive particles have an average particle diameter of 3.3 μm, the conductive adhesive layer has a thickness of 5 μm. It is not unevenly distributed on one side of the film.

DESCRIPTION OF SYMBOLS 1... Connection structure, 4... Circuit component, 5... Substrate, 5a... Substrate surface, 7... Conductive particles, 8... Adhesive layer, 9... Anisotropically conductive film, 42... Projection electrode, 42a... Projection electrode Surface, d... Distance between the surface of the protruding electrode and the surface of the substrate.

Claims (4)

A method of manufacturing a connection structure comprising a connection step of connecting a circuit component having a protruding electrode and a substrate via an anisotropic conductive film in which conductive particles are dispersed in an adhesive layer,
As the anisotropic conductive film, using the anisotropic conductive film, the conductive particles are unevenly distributed on one side of the anisotropic conductive film,
The connecting step is
The anisotropic conductive film is arranged between the circuit component and the substrate so that the one surface side faces the substrate side, and heated at 40° C. to 100° C., and 2 MPa to the total electrode area of the protruding electrode. By pressing at 10 MPa, the protrusion electrodes are pushed into the anisotropic conductive film so that the distance between the surface of the protrusion electrodes and the surface of the substrate is 150% or less of the average particle diameter of the conductive particles. A method for manufacturing a connection structure, comprising a temporary fixing step. In the temporary fixing step, the protrusion electrode is pushed into the anisotropic conductive film so that the distance between the surface of the protrusion electrode and the surface of the substrate is 100% or less of the average particle diameter of the conductive particles. The method for manufacturing the connection structure according to claim 1. In the temporary fixing step, the protrusion electrode is pushed into the anisotropic conductive film so that the distance between the surface of the protrusion electrode and the surface of the substrate is less than 100% of the average particle diameter of the conductive particles. The method for manufacturing the connection structure according to claim 1. In the connecting step, after the temporary fixing step, by heating and further pushing the protruding electrode into the anisotropic conductive film, the protruding electrode and the substrate are electrically connected via the conductive particles. The method for manufacturing a connection structure according to claim 1, further comprising a main fixing step.

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