TW201705618A - Method for producing connected structure - Google Patents

Abstract

The present invention provides a method for producing a connected structure, which comprises a connection step for connecting a substrate 5 and a circuit component 4 having a projected electrode 42 with an anisotropic conductive film 9 being interposed therebetween, said anisotropic conductive film 9 being obtained by dispersing conductive particles 7 in an adhesive layer 8. With respect to the anisotropic conductive film 9, the conductive particles 7 are unevenly gathered in one surface of the anisotropic conductive film 9. The connection step comprises a temporary fixing step wherein the anisotropic conductive film 9 is arranged between the circuit component 4 and the substrate 5 such that the above-described one surface faces the substrate 5, and the projected electrode 42 is pressed into the anisotropic conductive film 9 so that the distance d between a surface 42a of the projected electrode 42 and a surface 5a of the substrate 5 is 150% or less of the average particle diameter of the conductive particles 7.

Description

Manufacturing method of connecting structure

The present invention relates to a method of manufacturing a bonded structure.

When a substrate such as a glass panel for liquid crystal display is connected to a circuit component such as a liquid crystal driving integrated circuit (IC) to form a bonded structure, the conductive particles are dispersed in the adhesive layer. In the case of an anisotropic conductive film. At this time, a plurality of protruding electrodes provided on the circuit component can be collectively connected to the substrate.

In recent years, with the development of electronic devices, the density of wiring and the high functionality of circuits have been being carried out. As a result, a small area of the bump electrodes and a small pitch are being sought. In order to obtain a stable electrical connection in the connection of such bump electrodes, it is necessary to interpose a sufficient number of conductive particles between the bump electrodes and the substrate.

In order to solve such a problem, for example, Patent Document 1 discloses a method for producing a bonded structure in which an electrically conductive particle of the anisotropic conductive film is present in the vicinity of a single-sided surface of the anisotropic conductive film. [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-103545

[Problems to be solved by the invention]

However, even when the conventional anisotropic conductive film is used, when the bonded structure is produced by heating and pressurizing, the adhesive component of the anisotropic conductive film flows, and accordingly, conductive The particles flow out between the protruding electrodes and the substrate. At this time, there is a fear that a sufficient number of conductive particles are not interposed between the bump electrodes and the substrate.

The present invention has been made to solve the above problems, and an object thereof is to provide a method for producing a bonded structure in which a sufficient number of conductive particles can be interposed between a bump electrode and a substrate. [Means for solving the problem]

In order to solve the above problems, the method for manufacturing a bonded structure according to the present invention includes a connecting step of disposing a circuit component having a bump electrode and a substrate through an anisotropic conductive film in which conductive particles are dispersed in an adhesive layer. In the case of connecting, an anisotropic conductive film in which one side of the anisotropic conductive film is concentrated on the conductive film is used as an anisotropic conductive film, and the connecting step includes a temporary fixing step of bringing the anisotropic conductive film to one side. The side surface is disposed between the circuit component and the substrate, and the protrusion electrode is pressed into the opposite direction such that the distance between the surface of the bump electrode and the surface of the substrate becomes 150% or less of the average particle diameter of the conductive particles. In the conductive film.

In the method for producing a bonded structure, the protruding electrode is pressed into the anisotropic conductive film such that the distance between the surface of the bump electrode and the surface of the substrate becomes 150% or less of the average particle diameter of the conductive particles. The adhesive component of the anisotropic conductive film can be excluded from the protruding electrode and the substrate in advance. As a result, the amount of the binder component existing between the bump electrode and the substrate is reduced. Therefore, even when the binder component flows due to heating and pressurization in the subsequent main fixing step, the conductive particles can be suppressed. The protruding electrode flows out between the substrate. Therefore, it is preferable to trap the conductive particles between the bump electrodes and the substrate, so that a sufficient number of conductive particles can be interposed between the bump electrodes and the substrate in the obtained connection structure.

In the temporary fixing step, the protruding electrode can be pressed into the anisotropic conductive film so that the distance between the surface of the bump electrode and the surface of the substrate becomes 100% or less of the average particle diameter of the conductive particles. At this time, since the conductive particles are temporarily fixed in a state in which the conductive particles are in contact with the bump electrodes and the substrate, the conductive particles can be more easily caught between the bump electrodes and the substrate.

In the temporary fixing step, the protruding electrode can be pressed into the anisotropic conductive film so that the distance between the surface of the bump electrode and the surface of the substrate becomes less than 100% of the average particle diameter of the conductive particles. At this time, since the conductive particles are trapped between the bump electrode and the substrate in the temporary fixing step, the outflow of the conductive particles caused by the flow of the binder component of the anisotropic conductive film is further suppressed. The conductive particles can be further preferably captured between the bump electrode and the substrate.

The connecting step further includes a formal fixing step of electrically connecting the protruding electrode and the substrate via the conductive particles by further pressing the protruding electrode into the anisotropic conductive film while heating is performed. . At this time, since the adhesive component is removed from the protruding electrode and the substrate in advance in the temporary fixing step, the protruding electrode is further pressed into the anisotropic conductive film even during heating in the main fixing step. It is also possible to suppress the conductive particles from flowing out between the protruding electrodes and the substrate, so that the conductive particles can be preferably caught between the protruding electrodes and the substrate. Therefore, a sufficient number of conductive particles can be interposed between the bump electrode and the substrate in the bonded structure. [Effects of the Invention]

According to the present invention, a sufficient number of conductive particles can be interposed between the bump electrode and the substrate.

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

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, for example, an electronic device 2 such as a touch panel. The electronic device 2 includes, 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 mm to 300 mm × 20 mm to 400 mm and a thickness of 0.1 mm to 0.3 mm. As the substrate 5, for example, a glass substrate formed of non-alkali glass or the like can be used. A circuit electrode (not shown) is formed on the surface 5a of the substrate 5 so as to correspond to the liquid crystal display portion 6 and the bump electrode 42 (described later) of the circuit component 4. The liquid crystal display unit 6 is mounted on the surface 5a of the substrate 5 and is connected to the circuit electrode.

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

Fig. 2 is a plan view showing a connection structure. As shown in FIG. 2, the circuit component 4 has a body portion 41 and a bump electrode 42 provided on the body portion 41. The main body portion 41 has a mounting surface 41a and has a non-mounting surface 41b on the opposite side of the mounting surface 41a. In the connection structure 1, the circuit component 4 is disposed such that the substrate 5 faces the mounting surface 41a. A plurality of protruding electrodes (for example, bump electrodes) 42 protruding from the mounting surface 41a are formed in the main body portion 41. As a material for forming the body portion 41 of the circuit component 4, helium or the like can be used. The bump electrode 42 is formed of a soft material (Au or the like) which is electrically conductive particles (described later in detail) contained in the opposite-direction conductive film.

As shown in FIG. 2, on the mounting surface 41a, for example, along one of the long sides 41c of the mounting surface 41a, the plurality of protruding electrodes 42 are arranged in a substantially equal interval, and along the other long side 41d of the mounting surface 41a, The plurality of protruding electrodes 42 are arranged at substantially equal intervals and in a zigzag manner across three rows. One row of the bump electrodes 42 disposed on one of the long sides 41c side is, for example, an input side electrode, and the three rows of bump electrodes 42 disposed on the other long side 41d side are, for example, electrodes on the output side. The bump electrode 42 has a height of, for example, 2 μm to 15 μm (a height from the mounting surface 41a). In addition, the mounting surface 41a may be disposed along one of the long sides 41c, and the plurality of protruding electrodes 42 may be arranged across, for example, two rows to four rows, and the plurality of protruding electrodes 42 may be spanned along the other long side 41d. And configured, for example, two or four lines.

Fig. 3 is a schematic cross-sectional view showing a cross section taken along the line I-I in Fig. 2; As shown in FIG. 3, in the connection structure 1, the circuit component 4 and the substrate 5 are connected to each other via 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 exhibiting curability by heat or light can be widely used, and for example, an epoxy adhesive or an acrylic adhesive can be used. . A crosslinkable material can be preferably used in terms of excellent heat resistance and moisture resistance after the connection. Among them, an epoxy-based adhesive containing an epoxy resin as a thermosetting resin as a main component can be preferably used because it can be cured in a short period of time, has good connection workability, and is excellent in adhesion.

Specific examples of the epoxy-based adhesive include an adhesive mainly composed of a high molecular weight epoxy resin, a solid epoxy resin or a liquid epoxy resin, or a urethane or a polycondensate. A modified epoxy resin obtained by modifying these epoxy resins, such as an ester, an acrylic rubber, a nitrile rubber (NBR), or a synthetic linear polyamine. The epoxy-based adhesive usually contains the epoxy resin as a main component, a curing agent, a catalyst, a coupling agent, a filler, and the like.

Specific examples of the acrylic adhesive include an adhesive containing an acrylic resin (polymer or copolymer) as a main component, and the acrylic resin is at least one of acrylic acid, acrylate, methacrylate, and acrylonitrile. As a monomer component.

The conductive particles 7 contained in the anisotropic conductive film 9 are exemplified by particles of a metal such as Au, Ag, Pt, Ni, Cu, W, Sb, Sn, solder, or conductive carbon. The conductive particles 7 may be coated particles in which particles formed of non-conductive glass, ceramic, plastic, or the like are used as a core, and the core is coated with the metal, conductive carbon, or the like. Made. The shape of the conductive particles 7 before the connection may be, for example, a substantially spherical shape or a shape in which a plurality of protrusions protrude in the radial direction (star shape).

The average particle diameter of the conductive particles 7 before the connection is preferably from 1 μm to 18 μm, more preferably from 2 μm to 4 μm, from the viewpoint of dispersibility and conductivity. Within this range, conductive particles having an average particle diameter larger than the height of the bump electrodes 42 are preferably used, but conductive particles having an average particle diameter of, for example, 80% to 100% of the height of the bump electrodes 42 may be used. The average particle diameter of the conductive particles 7 can be obtained by measuring the particle diameter by using a Scanning Electron Microscope (SEM) for 300 arbitrary conductive particles, and taking the particle diameters. average value. When the conductive particles 7 have a projection or the like that is not spherical, the particle diameter of the conductive particles 7 may be a diameter of a circle circumscribing the conductive particles in the image of the SEM.

Next, a method of manufacturing the bonded structure of the present embodiment will be described. The manufacturing method of the connection structure of this embodiment includes a connection step including a temporary fixing step and a formal fixing step. 4(a) and 4(b) are schematic cross-sectional views showing a temporary fixing step in the method of manufacturing the bonded structure. In the temporary fixing step, as shown in FIG. 4(a), the anisotropic conductive film in which the conductive particles 7 are concentrated on the one surface 9a side of the anisotropic conductive film 9 is used as the anisotropic conductive film 9, and is anisotropically The anisotropic conductive film 9 is disposed 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 are located only on the side of the one surface 9a side of the anisotropic conductive film 9 in a range of preferably 150% or less of the average particle diameter of the conductive particles 7, more preferably 130% or less, and still more preferably 110%. The following range.

In the anisotropic conductive film 9, the method in which the conductive particles 7 are concentrated on the one surface 9a side of the anisotropic conductive film 9 is not particularly limited. For example, the conductive particles 7 are concentrated on the side of the one surface 9a of the anisotropic conductive film 9 and the conductive film containing the conductive particles 7 can be laminated on one side of the insulating adhesive layer containing no conductive particles 7. Formed by a layer of adhesive. At this time, the thickness of the conductive adhesive layer is preferably, for example, 0.6 times or more and less than 1.0 times the average particle diameter of the conductive particles 7.

The content of the conductive particles 7 in the anisotropic conductive film 9 is prevented from being different from the conductive particles 7 in the anisotropic conductive film 9 from the viewpoint of preventing a short circuit caused by the excessive presence of the conductive particles 7. The volume fraction is preferably from 1 part by volume to 100 parts by volume, more preferably from 10 parts by volume to 50 parts by volume. The particle density of the conductive particles 7 in the anisotropic conductive film 9 may be, for example, 5,000 / mm ² or more and 50,000 / mm ² or less.

In the temporary fixing step, as shown in FIG. 4(b), the circuit is pressed by the direction of the opposing direction of the circuit component 4 and the substrate 5 (the direction of the arrow in FIG. 4(b)) while heating is performed. The protruding electrode 42 of the part 4 is pressed into the anisotropic conductive film 9. The heating temperature and pressure at this time are preferably heating temperatures and pressures at which the binder component of the anisotropic conductive film 9 flows and the conductive particles 7 are prevented from flowing out between the bump electrodes 42 and the substrate 5. And respectively, the heating temperature and pressure in the subsequent formal fixing step are below. Specifically, the heating temperature is, for example, 40° C. to 100° C., and the pressure is, for example, 2 MPa to 10 MPa with respect to the total electrode area of the bump electrode 42 of the circuit component 4 .

Fig. 5 is an enlarged schematic cross-sectional view showing the main part of Fig. 4(b). As shown in FIG. 5, in the temporary fixing step, the distance d between the surface 42a of the bump 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, and more preferably The protruding electrode 42 of the circuit component 4 is pressed into the anisotropic conductive film 9 so as to be 120% or less, more preferably 100% or less, and particularly preferably less than 100%. On the other hand, the distance d can be, for example, 0.4 times (40%) or more with respect to 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 bonded structure after the main fixing step described later. The distance d between the surface 42a of the bump electrode 42 and the surface 5a of the substrate 5 can be calculated by, for example, observing the temporarily fixed circuit component 4 and the substrate 5 from the substrate 5 side using a metal microscope, according to the surface 42a of the bump electrode 42. The focal length is calculated from the difference in focal length of the surface 5a of the substrate 5.

In the method of manufacturing the bonded structure of the present embodiment, the main fixing step is performed after the temporary fixing step. Fig. 6 is a schematic cross-sectional view showing a formal 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 while being applied to the opposing direction of the circuit component 4 and the substrate 5 (the direction of the arrow in FIG. 6). The projection electrode 42 of the circuit component 4 is further pressed into the anisotropic conductive film 9 by pressing. The heating temperature and pressure at this time are respectively higher than the heating temperature and pressure in the 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 with respect to the total surface electrode of the bump electrode 42 of the circuit component 4 .

Thereby, the adhesive component of the anisotropic conductive film 9 further flows, and the distance d between the surface 42a of the bump electrode 42 and the surface 5a of the substrate 5 is further shortened. As a result, the flattening ratio of the conductive particles 7 is, for example, 30% or more, thereby securing the connection of the circuit component 4 to the substrate 5. Further, the adhesive layer 8 is cured in a state where the conductive particles 7 are engaged with the protruding electrode 42 and the substrate 5, and the protruding electrode 42 and the circuit electrode (not shown) of the substrate 5 corresponding thereto are passed via The conductive structure 7 is electrically connected, and the adjacent protruding electrodes 42, 43 and the adjacent circuit electrodes are electrically insulated from each other to obtain the bonded structure 1 shown in FIG. In addition, when the adhesive component of the anisotropic conductive film 9 contains a photocurable resin, the adhesive layer 8 is hardened by irradiating, for example, ultraviolet light while performing heating and pressurization in the main fixing step. Just fine.

In the method of manufacturing the connection structure, in the temporary fixing step, the protrusion d is previously formed so that the distance d between the surface 42a of the bump electrode 42 and the surface 5a of the substrate 5 becomes 150% or less of the average particle diameter of the conductive particles. After the electrode 42 is pressed into the anisotropic conductive film 9, the bump electrode 42 is further pressed into the anisotropic conductive film 9 in the main fixing step. Here, in the conventional method for manufacturing a bonded structure in which the temporary fixing step is not performed, the adhesive component of the anisotropic conductive film flows in a single step. Therefore, there is a concern that as the adhesive component rapidly flows, the conductive particles flow out from between the protruding electrode and the substrate, and a sufficient number of conductive particles are not interposed between the protruding electrode and the substrate.

On the other hand, in the method of manufacturing the bonded structure, the adhesive component of the anisotropic conductive film 9 can be removed from the protruding electrode 42 and the substrate 5 in advance by performing the temporary fixing step. As a result, the amount of the binder component existing between the bump electrode 42 and the substrate 5 is reduced. Therefore, even when the binder component flows due to heating and pressurization in the subsequent main fixing step, the conductive component can be suppressed. The particles 7 flow out from between the bump electrodes 42 and the substrate 5. Therefore, the conductive particles 7 are preferably trapped between the bump electrode 42 and the substrate 5, so that a sufficient number of conductive particles 7 can be interposed between the bump electrode 42 and the substrate 5 in the obtained connection structure 1. between.

The effect of the above-described effects is exhibited when the conductive particles 7 are concentrated on the surface of the one surface 9a of the anisotropic conductive film 9 as the anisotropic conductive film 9 . The reason for this is that the fluidity of the adhesive component of the counter conductive film 9 on the interface side (the side of the one surface 9a) of the counter conductive film 9 is lower than that of the anisotropic conductive film 9 from the viewpoint of the fluidity of the fluid. The fluidity of the adhesive component in the central part. Therefore, the flow of the conductive particles 7 concentrated on the side 9a having a low fluidity is further suppressed by the conductive particles 7 disposed on the entire surface of the anisotropic conductive film, and it is considered that the above-described effects are remarkably exhibited.

In the temporary fixing step, the projection electrode 42 is pressed into the opposite direction so that the distance d between the surface 42a of the bump electrode 42 and the surface 5a of the substrate 5 becomes 100% or less of the average particle diameter of the conductive particles 7. In the case of the conductive film 9, the conductive particles 7 are temporarily fixed in a state in which the conductive particles 7 are in contact with the bump electrodes 42 and the substrate 5, so that the conductive particles 7 can be more easily caught between the bump electrodes 42 and the substrate 5.

Further, in the temporary fixing step, the projection electrode 42 is pressed into the opposite direction such that the distance d between the surface 42a of the bump electrode 42 and the surface 5a of the substrate 5 becomes less than 100% of the average particle diameter of the conductive particles 7. In the case of the conductive film 9, the conductive particles 7 are caught between the bump electrode 42 and the substrate 5 in the temporary fixing step, and thus the flow of the adhesive component of the anisotropic conductive film 9 occurs. The outflow of the conductive particles 7 is further suppressed, and the conductive particles 7 can be more preferably captured between the bump electrodes 42 and the substrate 5. [Examples]

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

[Example 1-1 to Example 1-3, Comparative Example 1-1] (Synthesis of phenoxy resin a) A Dimroth cooling tube, a calcium chloride tube, and a stirring motor were attached ( Motor) Teflon (registered trademark) stir bar 3000 mL three-neck flask (flask), 4,4'-(9-fluorenylene)-diphenol 45 g (Japan Sigma Oric (Manufactured by Sigma-Aldrich Japan Co., Ltd.), and 3,3',5,5'-tetramethylbiphenol diglycidyl ether 50 g (manufactured by Mitsubishi Chemical Corporation: YX-4000H) dissolved in N- The reaction solution was prepared by using methylpyrrolidone in 1000 mL. 21 g of potassium carbonate was added thereto, and the mixture was stirred while heating to 110 ° C by a mantle heater. After stirring for 3 hours, the reaction liquid was added dropwise to a beaker containing 1000 mL of methanol, and the resulting precipitate was filtered by suction and filtered. The precipitate collected was further washed 3 times with 300 mL of methanol to obtain 75 g of phenoxy resin a.

Thereafter, the molecular weight of the phenoxy resin a was measured using a High Performance Liquid Chromatograph GP8020 manufactured by Tosoh Co., Ltd. (measurement conditions are as described above). As a result, Mn = 15769, Mw = 38,045, and Mw / Mn = 2.413 in terms of styrene.

(Production of the anisotropic conductive film A) When a paste for a conductive adhesive layer is formed, 50 parts by mass of a bisphenol A type epoxy as an epoxy compound is blended in terms of a solid content. Resin (manufactured by Mitsubishi Chemical Corporation: jER828), 5-hydroxyphenylmethylbenzylphosphonium hexafluoroantimonate as a curing agent in terms of solid content, and 50 parts by mass in terms of solid content A phenoxy resin a as a film forming material. Further, as the conductive particles, a nickel layer having a thickness of 0.2 μm was provided on the surface of particles having styrene as a core, and conductive particles having an average particle diameter of 3.3 μm and a specific gravity of 2.5 were produced, and the conductive particles were 50 parts by mass. Further formulated into the formulation. Then, the adhesive paste was applied to a polyethylene terephthalate (PET) film having a thickness of 50 μm using a coater and dried, thereby obtaining a PET formed on the PET. A conductive adhesive layer having a thickness of 3 μm on the film.

Next, in the case of forming an adhesive paste for an insulating adhesive layer, 45 parts by mass of a bisphenol F-type epoxy resin as an epoxy compound (manufactured by Mitsubishi Chemical Corporation: jER807) is blended in terms of solid content. 5 parts by mass of 4-hydroxyphenylmethylbenzyl hexafluoroantimonate as a curing agent and 55 parts by mass of a bisphenol A·double as a film forming material in terms of a solid content Phenol F copolymerized phenoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.: YP-70). Then, the adhesive paste was applied onto a PET film having a thickness of 50 μm using a coater and dried, whereby an insulating adhesive layer having a thickness of 14 μm formed on the PET film was obtained. Thereafter, the conductive adhesive layer and the insulating adhesive layer were heated to 40° C. and bonded by a hot roll laminator to obtain an anisotropic conductive film A sandwiched between the PET films. .

With respect to the obtained anisotropic conductive film A, the number of conductive particles per 25,000 μm ² was measured at 20 locations, and the average value was converted into 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 280,000 / mm ² .

(Production of Connection Structure) As a circuit component, an IC chip in which bump electrodes are arranged is prepared (outer shape is 2 mm × 20 mm, thickness is 0.3 mm, and bump electrode area is 840 μm ² (length 70 μm) × 12 μm horizontal), the space between the bump electrodes is 12 μm, and the height of the bump electrode is 15 μm). Further, as a substrate, a wiring pattern of indium tin oxide (ITO) was formed on the surface of a glass substrate (manufactured by Corning: #1737, 38 mm × 28 mm, thickness: 0.3 mm). (Substrate with a pattern width of 31 μm and an interelectrode space of 7 μm).

A thermocompression bonding apparatus is used for the connection of the IC wafer to the glass substrate, the thermocompression bonding apparatus including a stage (150 mm × 150 mm) including a ceramic heater and a tool (3 mm × 20) Mm). Then, the PET film on the side of the conductive adhesive layer of the anisotropic conductive film A (2.5 mm × 25 mm) was peeled off, and heated and pressurized at 80 ° C and 0.98 MPa for 2 seconds to conduct conductivity. The surface on the side of the adhesive layer is attached to the glass substrate.

Then, after the bump electrodes of the IC wafer and the circuit electrodes of the glass substrate are aligned, the heating and pressing are performed for 1 second at the temporary fixed temperature and the temporary fixed pressure shown in Table 1, and the bumps of the IC wafer are removed. The electrode is pressed into the anisotropic conductive film A. The distance between the temporarily fixed glass substrate and the bump electrode is shown in Table 1. Further, the distance between the temporarily fixed substrate and the bump electrode was calculated from the glass substrate side using a metal microscope, and 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.

Then, heating and pressurization were carried out for 5 seconds under conditions of 160 ° C and 70 MPa, whereby the IC wafer was formally fixed to the glass substrate to obtain a bonded structure. The capture ratio of the conductive particles in the bonded structure was calculated based on the following formula. Capture rate (%) = (number of conductive particles on the bump electrode / (1 mm ² / bump electrode area) / number of conductive particles per 1 mm ² of the anisotropic conductive film) × 100 In addition, using a metal microscope, The number of conductive particles was measured for 200 portions of the bump electrode, and the average value thereof was defined as the number of conductive particles on the bump electrode. The results are shown in Table 1.

[Table 1] <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Comparative Example 1-1 </td>< Td> Example 1-1 </td><td> Example 1-2 </td><td> Example 1-3 </td></tr><tr><td> Average particle of conductive particles Diameter Dp[μm] </td><td> 3.3 </td></tr><tr><td> Particle density of conductive particles [/mm²] </td>< Td> 28000 </td></tr><tr><td> Adhesive layer composition</td><td> Insulating adhesive layer [μm] </td><td> 14 </td> </tr><tr><td> Conductive Adhesive Layer [μm] </td><td> 3 </td></tr><tr><td> Bump Electrode Composition</td>< Td> area [μm²] </td><td> 840 </td></tr><tr><td> height [μm] </td><td> 15 </ Td></tr><tr><td> Temporary fixed temperature [°C] </td><td> 30 </td><td> 50 </td><td> 70 </td><td> 90 </td></tr><tr><td> Temporary fixed pressure [MPa] </td><td> 3.3 </td></tr><tr><td> Substrate-bump electrode distance d [μm] </td><td> 9.4 </td><td> 4.8 </td><td> 2.4 </td><td> 1.8 </td></tr><tr><td> d /Dp×100[%] </td><td> 285 </td><td> 145 </td><td> 73 </td><td> 55 </td></tr><tr> <td> Capture rate of conductive particles [%] </td> <td> 58.9 </td><td> 60.7 </td><td> 62.6 </td><td> 63.3 </td></tr></TBODY></TABLE>

[Example 2-1 to Example 2-2, Comparative Example 2-1] (Production of Anisotropic Conductive Film B) A bisphenol A type phenoxy resin was used instead of the phenoxy resin a (Nippon Steel Co., Ltd. Chemical Co., Ltd. manufactures: YP-50), instead of bisphenol A·bisphenol F copolymerized phenoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.: YP-70), bisphenol F type phenoxy An anisotropic conductive film B was produced in the same manner as the anisotropic conductive film A except for the resin (manufactured by Nippon Steel & Metal Co., Ltd.: FX-316). With respect to 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 into 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 330,000 pieces/mm ² .

The bonded structure was produced 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 capturing ratio of the conductive particles was measured. The results are shown in Table 2.

[Table 2] <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Comparative Example 2-1 </td>< Td> Example 2-1 </td><td> Example 2-2 </td></tr><tr><td> Average particle diameter of conductive particles Dp[μm] </td><td> 3.3 </td></tr><tr><td> Particle density of conductive particles [/mm²] </td><td> 33000 </td></tr>< Tr><td> Composition of adhesive layer</td><td> Insulating adhesive layer [μm] </td><td> 14 </td></tr><tr><td> Conductivity Adhesive layer [μm] </td><td> 3 </td></tr><tr><td> Bump electrode composition </td><td> Area [μm<sup>2</sup >] </td><td> 840 </td></tr><tr><td> Height [μm] </td><td> 15 </td></tr><tr><td> Temporary fixed temperature [°C] </td><td> 30 </td><td> 50 </td><td> 70 </td></tr><tr><td> Temporary fixed pressure [MPa] </td><td> 3.3 </td></tr><tr><td> substrate-bump electrode distance d[μm] </td><td> 8.2 </td><td> 3.2 < /td><td> 1.9 </td></tr><tr><td> d/Dp×100[%] </td><td> 248 </td><td> 97 </td>< Td> 58 </td></tr><tr><td> Capture rate of conductive particles [%] </td><td> 54.1 </td><td> 56.4 </td><td> 60.5 < /td></tr></TBODY></TABLE >

[Example 3-1 to Example 3-2, Comparative Example 3-1 to Comparative Example 3-2] The thickness of the insulating adhesive layer was changed as shown in Table 3, and the examples were In the same manner as in Table 1-1, the bonded structure was produced under the conditions shown in Table 3, and the capturing ratio of the conductive particles was measured. The results are shown in Table 3.

[Table 3] <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Example 3-1 </td>< Td> Comparative Example 3-1 </td><td> Example 3-2 </td><td> Comparative Example 3-2 </td></tr><tr><td> Average particle of conductive particles Diameter Dp[μm] </td><td> 3.3 </td></tr><tr><td> Particle density of conductive particles [/mm²] </td>< Td> 28000 </td></tr><tr><td> Adhesive layer composition</td><td> Insulating adhesive layer [μm] </td><td> 17 </td> <td> 17 </td><td> 29 </td><td> 29 </td></tr><tr><td> Conductive Adhesive Layer [μm] </td><td> 3 </td></tr><tr><td> Bump electrode composition</td><td> Area [μm²] </td><td> 840 </td> </tr><tr><td> Height [μm] </td><td> 15 </td></tr><tr><td> Temporary fixed temperature [°C] </td><td> 70 </td><td> 50 </td><td> 70 </td><td> 50 </td></tr><tr><td> Temporary fixed pressure [MPa] </td><td > 3.3 </td></tr><tr><td> Substrate-bump electrode distance d[μm] </td><td> 3.9 </td><td> 7.4 </td><td> 2.7 </td><td> 7.8 </td></tr><tr><td> d/Dp×100[%] </td><td> 118 </td><td> 224 </td ><td> 82 </td><td> 236 </td></tr><t r><td> Capture rate of conductive particles [%] </td><td> 60.7 </td><td> 48.2 </td><td> 62.6 </td><td> 50.5 </td>< /tr></TBODY></TABLE>

[Example 3-1 to Example 3-2, Comparative Example 3-1 to Comparative Example 3-2] The thickness of the insulating adhesive layer and the height of the bump electrode were changed as shown in Table 4, except The bonded structure was produced under the conditions shown in Table 4 in the same manner as in Example 1-1, and the capturing ratio of the conductive particles was measured. The results are shown in Table 4.

[Table 4] <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Example 4-1 </td>< Td> Comparative Example 4-1 </td></tr><tr><td> Average particle diameter of conductive particles Dp[μm] </td><td> 3.3 </td></tr><tr> <td> Particle density of conductive particles [/mm²] </td><td> 28000 </td></tr><tr><td> Composition of adhesive layer </ Td><td> Insulating Adhesive Layer [μm] </td><td> 9 </td><td> 14 </td></tr><tr><td> Conductive Adhesive Layer [μm] </td><td> 3 </td></tr><tr><td> Bump electrode composition </td><td> Area [μm²] </ Td><td> 840 </td></tr><tr><td> height [μm] </td><td> 10 </td></tr><tr><td> temporary fixed temperature [ °C] </td><td> 50 </td></tr><tr><td> Temporary fixed pressure [MPa] </td><td> 3.3 </td></tr><tr>< Td> substrate-bump electrode distance d[μm] </td><td> 3.4 </td><td> 5.8 </td></tr><tr><td> d/Dp×100[% ] </td><td> 103 </td><td> 176 </td></tr><tr><td> Capture rate of conductive particles [%] </td><td> 57.5 </td ><td> 53.9 </td></tr></TBODY></TABLE>

[Reference Example 1-1 to Reference Example 1-3] The thickness 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, and In the same manner as in Example 1-1, the bonded structure was produced under the conditions shown in Table 5, and the capture ratio of the conductive particles was measured. The results are shown in Table 5. Further, in Reference Examples 1-1 to 1-3, the average particle diameter of the conductive particles was 3.3 μm, whereas the thickness of the conductive adhesive layer was 5 μm. Therefore, the conductive particles were not concentrated in the same manner. To one side of the conductive film.

[Table 5] <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> Reference Example 1-1 </td>< Td> Reference Example 1-2 </td><td> Reference Example 1-3 </td></tr><tr><td> Average particle diameter of conductive particles Dp[μm] </td><td> 3.3 </td></tr><tr><td> Particle density of conductive particles [/mm²] </td><td> 55000 </td></tr>< Tr><td> Composition of adhesive layer</td><td> Insulating adhesive layer [μm] </td><td> 12 </td></tr><tr><td> Conductivity Adhesive layer [μm] </td><td> 5 </td></tr><tr><td> Bump electrode composition </td><td> Area [μm<sup>2</sup >] </td><td> 840 </td></tr><tr><td> Height [μm] </td><td> 15 </td></tr><tr><td> Temporary fixed temperature [°C] </td><td> 30 </td><td> 50 </td><td> 70 </td></tr><tr><td> Temporary fixed pressure [MPa] </td><td> 3.3 </td></tr><tr><td> Substrate-bump electrode distance d[μm] </td><td> 10.9 </td><td> 5.4 < /td><td> 3.9 </td></tr><tr><td> d/Dp×100[%] </td><td> 330 </td><td> 164 </td>< Td> 118 </td></tr><tr><td> Capture rate of conductive particles [%] </td><td> 30.5 </td><td> 31.0 </td><td> 31.4 < /td></tr></TBODY></TA BLE>

1‧‧‧Connected structure
2‧‧‧Electronic equipment
3‧‧‧LCD panel
4‧‧‧ circuit parts
5‧‧‧Substrate
5a‧‧‧ Surface of the substrate
6‧‧‧Liquid display
7‧‧‧Electrical particles
8‧‧‧Adhesive layer
9‧‧‧ Anisotropic conductive film
9a‧‧‧One side of an anisotropic conductive film
41‧‧‧ Body Department
41a‧‧‧Installation surface
41b‧‧‧Non-installation surface
41c, 41d‧‧‧ long side
42‧‧‧ protruding electrode
42a‧‧‧ Surface of the protruding electrode
d‧‧‧Distance of the surface of the protruding electrode from the surface of the substrate

1 is a plan view showing an electronic device to which a connection structure according to an embodiment of the present invention is applied. Fig. 2 is a plan view showing the joint structure of Fig. 1; Fig. 3 is a schematic cross-sectional view showing a cross section taken along the line I-I in Fig. 2; 4(a) and 4(b) are schematic cross-sectional views showing a temporary fixing step in the method of manufacturing the joined structure of Fig. 1. Fig. 5 is an enlarged schematic cross-sectional view showing the main part of Fig. 4(b). Fig. 6 is a schematic cross-sectional view showing a subsequent main fixing step of Figs. 4(a) and 4(b).

4‧‧‧ circuit parts

5‧‧‧Substrate

5a‧‧‧ Surface of the substrate

7‧‧‧Electrical particles

8‧‧‧Adhesive layer

9‧‧‧ Anisotropic conductive film

41‧‧‧ Body Department

42‧‧‧ protruding electrode

42a‧‧‧ Surface of the protruding electrode

d‧‧‧Distance of the surface of the protruding electrode from the surface of the substrate

Claims (4)

A method for manufacturing a bonded structure, comprising a connecting step of connecting a circuit component having a bump electrode and a substrate via an anisotropic conductive film in which conductive particles are dispersed in an adhesive layer, The conductive particles are concentrated on the one side of the anisotropic conductive film as the anisotropic conductive film, and the connecting step includes a temporary fixing step, and the temporary fixing step is the opposite direction The conductive film is disposed between the circuit component and the substrate such that the one surface side faces the substrate side, and the distance between the surface of the bump electrode and the surface of the substrate becomes the conductive The protruding electrode is pressed into the anisotropic conductive film in such a manner that the average particle diameter of the particles is 150% or less. The method of manufacturing a bonded structure according to claim 1, wherein in the temporary fixing step, a distance between a surface of the protruding electrode and a surface of the substrate becomes an average of the conductive particles. The protruding electrode is pressed into the anisotropic conductive film in a manner of 100% or less of the particle diameter. The method of manufacturing the bonded structure according to the first or second aspect of the invention, wherein in the temporary fixing step, a distance between a surface of the protruding electrode and a surface of the substrate becomes smaller than The protruding electrode is pressed into the anisotropic conductive film in such a manner that 100% of the average particle diameter of the conductive particles is described. The method for manufacturing a bonded structure according to any one of claims 1 to 3, wherein the connecting step further comprises a formal fixing step after the temporary fixing step, wherein the formal fixing step is performed The protruding electrode is further pressed into the anisotropic conductive film while heating, and the protruding electrode and the substrate are electrically connected via the conductive particles.