KR20240018694A - Method for producing connected structure - Google Patents

Abstract

The present invention relates to a connection process in which a circuit component 4 having a protruding electrode 42 and a substrate 5 are connected via an anisotropic conductive film 9 in which conductive particles 7 are dispersed in an adhesive layer 8. A method of manufacturing a connected structure comprising: an anisotropic conductive film (9) in which conductive particles (7) are unevenly distributed on one side of the anisotropic conductive film (9), and the connection process includes: An anisotropic conductive film 9 is disposed between the circuit component 4 and the substrate 5 so as to face the substrate 5 side, and the surface 42a of the protruding electrode 42 and the surface 5a of the substrate 5 are A method for manufacturing a bonded structure is provided, including a temporarily fixing step of press-fitting the protruding electrodes 42 into the anisotropic conductive film 9 so that the distance d between them is 150% or less of the average particle diameter of the conductive particles 7.

Description

Method for manufacturing a connected structure {METHOD FOR PRODUCING CONNECTED STRUCTURE}

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

When manufacturing a connected structure by connecting a substrate such as a glass panel for a liquid crystal display and circuit components such as an IC for driving a liquid crystal, an anisotropic conductive film in which conductive particles are dispersed in an adhesive layer may be used. In this case, it becomes possible to connect a plurality of protruding electrodes provided on the circuit component to the board at a time.

Recently, with the development of electronic devices, the density of wiring and the functionality of circuits are becoming higher. As a result, efforts are being made to reduce the area and pitch of the protruding electrode. In order to obtain a stable electrical connection in the connection of such protruding electrodes, it is necessary to interpose a sufficient number of conductive particles between the protruding electrodes and the substrate.

Regarding this problem, for example, Patent Document 1 discloses a method of manufacturing a bonded structure using an anisotropic conductive film in which conductive particles exist near the surface of one side of the anisotropic conductive film.

Japanese Patent Publication No. 2007-103545

However, even when the conventional anisotropic conductive film described above is used, when heating and pressurizing the connection structure is produced, the adhesive component of the anisotropic conductive film flows, and the conductive particles flow out between the protruding electrode and the substrate along with this. There are cases. In this case, there is a risk that a sufficient number of conductive particles may not be interposed between the protruding electrode and the substrate.

The present invention was made to solve the above problems, and its purpose is to provide a method for manufacturing a bonded structure that allows a sufficient number of conductive particles to be interposed between a protruding electrode and a substrate.

In order to solve the above problem, the method of manufacturing a connected structure according to the present invention includes a connection step of connecting 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. This is a method of manufacturing a structure, which uses an anisotropic conductive film in which conductive particles are distributed on one side of the anisotropic conductive film as an anisotropic conductive film, and in the connection process, the anisotropic conductive film is connected to the circuit component and the substrate so that the one side faces the substrate. A temporary fixing step is provided for press-fitting 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.

In this method of manufacturing the connected structure, the protruding electrode is press-fitted 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, so that the anisotropic conductive film is formed between the protruding electrode and the substrate. Adhesive components can be excluded in advance. As a result, since the adhesive component existing between the protruding electrode and the substrate is reduced, even when the adhesive component flows due to heating and pressurization in the subsequent main fixing process, conductive particles are prevented from flowing out between the protruding electrode and the substrate. It can be suppressed. Therefore, since the conductive particles can be appropriately captured between the protruding electrode and the substrate, it becomes possible to interpose a sufficient number of conductive particles between the protruding electrode and the substrate in the resulting bonded structure.

In the temporary fixing process, the protruding electrode can be press-fitted into the anisotropic conductive film so that the distance between the surface of the protruding electrode 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 a state of contact with the protruding electrode and the substrate, the conductive particles can be captured more appropriately between the protruding electrode and the substrate.

In the temporary fixing process, the protruding electrode can be press-fitted into the anisotropic conductive film so that the distance between the surface of the protruding electrode and the surface of the substrate is less than 100% of the average particle diameter of the conductive particles. In this case, since the conductive particles are captured by engaging between the protruding electrode and the substrate in the temporary fixing process, the outflow of the conductive particles accompanying the flow of the adhesive component of the anisotropic conductive film is further suppressed, and the conductive particles are separated from the protruding electrode and the substrate. You can capture more appropriately between them.

The connection process may further include, after the temporary fixation process, a main fixation process in which the protrusion electrode and the substrate are electrically connected via conductive particles by further press-fitting the protrusion electrode into the anisotropic conductive film while heating. In this case, since the adhesive component is previously excluded from between the protruding electrode and the substrate in the temporary fixing process, even if the protruding electrode is further press-fitted into the anisotropic conductive film while heating in the main fixing process, conductive particles do not form between the protruding electrode and the substrate. Outflow can be suppressed, and conductive particles can be appropriately captured between the protruding electrode and the substrate. Therefore, in the bonded structure, it becomes possible to interpose a sufficient number of conductive particles between the protruding electrode and the substrate.

According to the present invention, it becomes possible to interpose a sufficient number of conductive particles between the protruding electrode and 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 connection structure of FIG. 1.
FIG. 3 is a schematic cross-sectional view showing a cross-section seen in the direction of arrow II in FIG. 2.
FIG. 4 is a schematic cross-sectional view showing a temporary fixing step in the manufacturing method of the bonded structure of FIG. 1.
Fig. 5 is an enlarged schematic cross-sectional view of the main part of Fig. 4(b).
FIG. 6 is a schematic cross-sectional view showing the subsequent main fixing process of FIG. 4.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of the manufacturing method of the bonded structure of this invention will be described in detail, referring 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 an electronic device 2, such as a touch panel, for example. The electronic device 2 is composed of, for example, a liquid crystal panel 3 and circuit components 4.

The liquid crystal panel 3 has, for example, a substrate 5 and a liquid crystal display portion 6. The substrate 5 has a rectangular plate shape, for example, with a size of 20 to 300 mm x 20 to 400 mm and a thickness of 0.1 to 0.3 mm. As the substrate 5, for example, a glass substrate formed of alkali-free glass or the like is used. Circuit electrodes, not shown, are formed on the surface 5a of the substrate 5 to correspond to the protruding electrodes 42 (described later) of the liquid crystal display portion 6 and the circuit component 4. The liquid crystal display portion 6 is installed on 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 x 10 to 50 mm, and a thickness of, for example, 0.1 to 0.3 mm. The circuit component 4 is spaced apart from the liquid crystal display portion 6 and is connected to the circuit electrode of the above-described substrate 5 (described in detail later).

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

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

FIG. 3 is a schematic cross-sectional view showing a cross-section seen in the direction of arrows II-I in FIG. 2. As shown in FIG. 3, in the connection structure 1, the circuit component 4 and the substrate 5 are connected through an anisotropic conductive film 9 in which conductive particles 7 are dispersed in an adhesive layer 8. are connected to each other.

As the adhesive component constituting the adhesive layer 8 of the anisotropic conductive film 9, a material that exhibits heat or light curability can be widely applied, 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, epoxy-based adhesives containing epoxy resin, which is a thermosetting resin, as a main component are preferably used because they can be cured in a short time, have good connection workability, and have excellent adhesive properties.

Specific examples of epoxy adhesives include high molecular weight epoxy resins, solid epoxy resins, or liquid epoxy resins, or modified epoxy resins obtained by modifying these epoxy resins with urethane, polyester, acrylic rubber, nitrile rubber (NBR), synthetic linear polyamide, etc. Examples include adhesives containing resin as a main component. Epoxy-based adhesives generally contain the epoxy resin as the main component, a curing agent, a catalyst, a coupling agent, a filler, etc.

Specific examples of acrylic adhesives include adhesives containing as a main component an acrylic resin (polymer or copolymer) containing at least one of acrylic acid, acrylic acid ester, methacrylic acid ester, and acrylonitrile as a monomer component.

Examples of the conductive particles 7 contained in the anisotropic conductive film 9 include particles formed of metals such as Au, Ag, Pt, Ni, Cu, W, Sb, Sn, solder, and conductive carbon. The conductive particles 7 may be coated particles formed by forming a particle made of non-conductive glass, ceramic, plastic, etc. as the core and covering the core with the above-mentioned metal, conductive carbon, etc. Examples of the shape of the conductive particles 7 before connection include a substantially spherical shape, a shape in which a plurality of protrusions protrude in the radial direction (star shape), and the like.

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

Next, the manufacturing method of the bonded structure according to this embodiment will be described. The manufacturing method of the connected structure according to the present embodiment includes a connecting process, and the connecting process includes a temporary fixing process and a final fixing process. Figure 4 is a schematic cross-sectional view showing the temporary fixing step in the method for manufacturing a bonded structure. In the temporarily fixing process, as shown in Figure 4 (a), the anisotropic conductive film 9 is an anisotropic conductive film in which conductive particles 7 are unevenly distributed on one surface 9a of the anisotropic conductive film 9. In use, the anisotropic conductive film 9 is placed between the circuit component 4 and the substrate 5 (the surface of the substrate 5) so that one surface 9a of the anisotropic conductive film 9 faces the substrate 5 side. (5a) above).

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

In the anisotropic conductive film 9, the method of distributing the conductive particles 7 on the one surface 9a side of the anisotropic conductive film 9 is not particularly limited. For example, an anisotropic conductive film in which conductive particles 7 are localized on the one surface 9a side of the anisotropic conductive film 9 has conductive particles ( 7) It is formed by laminating a conductive adhesive layer containing. In this case, 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 set to be other than the conductive particles 7 in the anisotropic conductive film 9 from the viewpoint of preventing short circuit due to excessive presence of conductive particles 7. For 100 parts by volume of the component, preferably 1 part by volume to 100 parts by volume, more preferably 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, 5000 pieces/mm2 or more and 50000 pieces/mm2 or less.

In the temporary fixing process, as shown in FIG. 4(b), the circuit component 4 and the substrate 5 are heated and pressed in opposite directions (the direction of the arrow in FIG. 4(b)). By doing so, the protruding electrode 42 of the circuit component 4 is press-fitted into the anisotropic conductive film 9. The heating temperature and pressure at this time are a heating temperature and pressure that can be maintained without causing the adhesive component of the anisotropic conductive film 9 to flow while preventing the conductive particles 7 from flowing out between the protruding electrode 42 and the substrate 5. This is preferable, and is less than or equal to the heating temperature and pressure in the subsequent main fixing process, respectively. 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 the main part of Fig. 4(b). As shown in FIG. 5, in the temporary fixing process, the distance d between the surface 42a of the protruding electrode 42 and the surface 5a of the substrate 5 is, with respect to the average particle diameter of the conductive particles 7, The protruding electrode 42 of the circuit component 4 is coated with the anisotropic conductive film 9 so that the protruding electrode 42 of the circuit component 4 is preferably 150% or less, more preferably 120% or less, even more preferably 100% or less, especially preferably less than 100%. ) is pressed into place. On the other hand, the distance d may 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 connection structure after the main fixing process described later. The distance d between the surface 42a of the protruding electrode 42 and the surface 5a of the substrate 5 is, for example, the circuit component 4 and the substrate temporarily fixed from the substrate 5 side using a metallurgical microscope. By observing (5), it can be calculated from the difference between the focal length of the surface 42a of the protruding electrode 42 and the focal distance of the surface 5a of the substrate 5.

In the manufacturing method of the bonded structure according to the present embodiment, the main fixing process is performed following the temporary fixing process. Figure 6 is a schematic cross-sectional view showing the main fixing process. As shown in FIG. 6, in the main fixing process, the circuit component 4, the substrate 5, and the anisotropic conductive film 9 are heated, and the circuit component 4 and the substrate 5 are heated in opposite directions ( By applying pressure in the direction of the arrow in FIG. 6, the protruding electrodes 42 of the circuit component 4 are further pressed into the anisotropic conductive film 9. The heating temperature and pressure at this time are respectively higher than the heating temperature and pressure in the temporary setting process described above. 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 area of the protruding electrodes 42 of the circuit component 4.

Accordingly, the adhesive component of the anisotropic conductive film 9 flows further, 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 becomes, for example, 30% or more, and the connection between the circuit component 4 and the substrate 5 is ensured. Then, by curing the adhesive layer 8 in a state in which the conductive particles 7 are engaged between the protruding electrode 42 and the substrate 5, the circuit electrode of the protruding electrode 42 and the corresponding substrate 5 (as shown) The connection structure 1 shown in FIG. 3 is electrically connected through the conductive particles 7, and the adjacent protruding electrodes 42 and 43 and the adjacent circuit electrodes are electrically insulated from each other. is obtained. In addition, when the adhesive component of the anisotropic conductive film 9 contains a photocurable resin, the adhesive layer 8 can be cured in the main fixing process by heating and pressurizing and irradiating ultraviolet light, for example. .

In this method of manufacturing the connected 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. After the protruding electrode 42 is previously press-fitted into the anisotropic conductive film 9, the protruding electrode 42 is further press-fitted into the anisotropic conductive film 9 in the main fixing process. Here, in the conventional method of manufacturing a bonded structure in which a main fixation process is performed without performing a temporary fixation process, the adhesive component of the anisotropic conductive film flows at once in the main fixation process. For this reason, there is a risk that conductive particles may flow out between the protruding electrode and the substrate due to the rapid flow of the adhesive component, and that a sufficient number of conductive particles may not be interposed between the protruding electrode and the substrate.

In contrast, in this method of manufacturing the bonded structure, the adhesive component of the anisotropic conductive film 9 can be excluded in advance from between the protruding electrode 42 and the substrate 5 by performing a temporary fixing process. As a result, the adhesive component existing between the protruding electrode 42 and the substrate 5 decreases, so even when the adhesive component flows due to heating and pressurization in the subsequent main fixing process, the conductive particles 7 Outflow between the protruding electrode 42 and the substrate 5 can be suppressed. Therefore, since the conductive particles 7 are appropriately captured between the protruding electrode 42 and the substrate 5, in the resulting bonded structure 1, a sufficient number of conductive particles 7 are placed between the protruding electrode 42 and the substrate 5. It becomes possible to sandwich it between the substrates 5.

The above-mentioned effects are significantly exhibited when an anisotropic conductive film 9 in which the conductive particles 7 are unevenly distributed on one surface 9a of the anisotropic conductive film 9 is used. For this reason, from the viewpoint of the fluidity of the fluid, the fluidity of the adhesive component on the interface side (one surface 9a side) of the substrate 5 of the anisotropic conductive film 9 is at the center of the anisotropic conductive film 9. It is mentioned that the fluidity is lower than that of the adhesive component. For this reason, the flow of the conductive particles 7 distributed on the side of the low-liquid surface 9a is suppressed more than that of the conductive particles 7 disposed throughout the anisotropic conductive film, and therefore the above-mentioned effect is significantly exhibited. I think so.

In addition, in the temporary fixing process, the protruding electrode ( When press-fitting 42 into the anisotropic conductive film 9, the conductive particles 7 are temporarily fixed in a state in contact with the protruding electrode 42 and the substrate 5, so the conductive particles 7 are attached to the protruding electrode 42. ) and the substrate (5) can be more appropriately captured.

In addition, in the temporary fixing process, the protruding electrode ( When press-fitting 42) into the anisotropic conductive film 9, the conductive particles 7 are captured by engaging between the protruding electrode 42 and the substrate 5 in the temporary fixing process, so the adhesive of the anisotropic conductive film 9 The outflow of the conductive particles 7 accompanying the flow of components is further suppressed, and the conductive particles 7 can be captured more appropriately between the protruding electrode 42 and the substrate 5.

Example

Hereinafter, the present invention will be described in more detail 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 Corporation) Kaku Co., Ltd. (YX-4000H) was dissolved in 1000 mL of N-methylpyrrolidone in a 3000 mL three-necked flask equipped with a Dimroth cooling tube, a calcium chloride tube, and a Teflon (registered trademark) stirring rod connected to a stirring motor. It was used as a reaction solution. 21 g of potassium carbonate was added to this, and the mixture was stirred while heating at 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 resulting precipitate was filtered out by suction filtration. The filtered precipitate was washed three more times with 300 mL of methanol, and 75 g of phenoxy resin a was obtained.

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

(Production of anisotropic conductive film A)

In forming the adhesive paste for the conductive adhesive layer, 50 parts by mass of bisphenol A type epoxy resin (JER828, manufactured by Mitsubishi Chemical Corporation) as an epoxy compound and 4-hydroxyphenylmethylbenzylsulfonium hexafluoro as a curing agent. 5 parts by mass of antimonate as a solid content and 50 parts by mass of phenoxy resin a as a film forming material were blended. Additionally, as a conductive particle, a nickel layer with a thickness of 0.2 μm was formed on the surface of the particle with polystyrene as the core, and conductive particles with an average particle diameter of 3.3 μm and a specific gravity of 2.5 were produced, and 50 parts by mass of these conductive particles were further mixed into the above mixture. did. Then, this adhesive paste was applied to a PET film with a thickness of 50 μm using a coater and dried, thereby obtaining a conductive adhesive layer with a thickness of 3 μm formed on the PET film.

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

For the obtained anisotropic conductive film A, the number of conductive particles per 25000 ㎛ 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 conductive particles in the anisotropic conductive film A was 280,000 particles/mm2.

(Production of connection structure)

As a circuit component, an IC chip with bump electrodes arranged (outside 2 mm × 20 mm, thickness 0.3 mm, bump electrode area 840 μm ² (70 μm vertical × 12 μm horizontal), space between bump electrodes 12 μm, bump electrode height 15㎛) was prepared. Additionally, as a substrate, a substrate having an ITO wiring pattern (pattern width 31 μm, inter-electrode space 7 μm) formed on the surface of a glass substrate (#1737, manufactured by Corning, Inc., 38 mm x 28 mm, thickness 0.3 mm) was prepared.

To connect the IC chip and the glass substrate, a thermocompression bonding device consisting of a stage (150 mm x 150 mm) containing a ceramic heater and a tool (3 mm x 20 mm) was used. Then, the PET film on the conductive adhesive layer side of the anisotropic conductive film A (2.5 mm x 25 mm) is peeled off, and the surface on the conductive adhesive layer side is attached to the glass substrate by heating and pressing for 2 seconds under the conditions of 80°C and 0.98 MPa. did.

Next, after aligning the positions of the bump electrode of the IC chip and the circuit electrode of the glass substrate, heating and pressurization are performed for 1 second at the temporary setting temperature and temporary setting pressure shown in Table 1, and the bump electrode of the IC chip is attached to the anisotropic conductive film A. Pressed in. The distance between the temporarily fixed glass substrate and the bump electrode is shown in Table 1. In addition, the distance between the temporarily fixed substrate and the bump electrode was observed from the glass substrate side using a metallurgical microscope, and calculated from the difference between the surface focal length of the glass substrate and the surface focal length of the bump electrode.

Subsequently, the IC chip was permanently fixed to the glass substrate by heating and pressurizing under conditions of 160°C and 70 MPa for 5 seconds, and a connection structure was obtained. The capture rate of electrically conductive particles in the bonded structure was calculated based on the following formula.

Capture rate (%) = (Number of conductive particles on bump electrode/(1㎟/bump electrode area)/Number of conductive particles per 1㎟ of anisotropic conductive film) x 100

Additionally, the number of conductive particles was measured at 200 locations of the bump electrode using a metallurgical microscope, and the average value was taken as the number of conductive particles on the bump electrode. The results are shown in Table 1.

[Examples 2-1 to 2-2, Comparative Example 2-1]

(Production of anisotropic conductive film B)

Instead of phenoxy resin a, use bisphenol A type phenoxy resin (YP-50, manufactured by Nippon Chemical Co., Ltd.) and bisphenol A/bisphenol F copolymerized phenoxy resin (manufactured by Nippon Chemical Co., Ltd.). : Anisotropic conductive film B was made in the same manner as anisotropic conductive film A, except that bisphenol F type phenoxy resin (FX-316, manufactured by Nippon Chemical Co., Ltd.) was used instead of YP-70). Produced. For the obtained anisotropic conductive film B, the number of conductive particles per 25000 ㎛ 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 conductive particles in the anisotropic conductive film B was 330,000 particles/mm2.

In the same manner as in Example 1-1 except for using the anisotropic conductive film B, a bonded structure was produced under the conditions shown in Table 2, and the capture rate of conductive particles was measured. The results are shown in Table 2.

[Examples 3-1 to 3-2, Comparative Examples 3-1 to 3-2]

Except that the thickness of the insulating adhesive layer was changed as shown in Table 3, the bonded structure was manufactured in the same manner as in Example 1-1 under the conditions shown in Table 3, and the capture rate of conductive particles was measured. The results are shown in Table 3.

[Examples 3-1 to 3-2, Comparative Examples 3-1 to 3-2]

Except that the thickness of the insulating adhesive layer and the height of the bump electrode were changed as shown in Table 4, the connection structure was manufactured in the same manner as in Example 1-1 under the conditions shown in Table 4, and the capture rate of the conductive particles was Measured. The results are shown in Table 4.

[Reference Examples 1-1 to 1-3]

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, the connection structure was manufactured in the same manner as in Example 1-1 under the conditions shown in Table 5. , the capture rate of conductive particles was measured. The results are shown in Table 5. In addition, in Reference Examples 1-1 to 1-3, the average particle diameter of the conductive particles was 3.3 μm and the thickness of the conductive adhesive layer was 5 μm, so the conductive particles were not unevenly distributed on one side of the anisotropic conductive film. not.

1: Connection structure
4: Circuit parts
5: substrate
5a: Surface of the substrate
7: Conductive particles
8: Adhesive layer
9: Anisotropic conductive film
42: protruding electrode
42a: Surface of protruding electrode
d: Distance between the surface of the protruding electrode and the surface of the substrate.

Claims (4)

A method for manufacturing a connected structure comprising a connection step of connecting 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,
The anisotropic conductive film is an anisotropic conductive film in which the conductive particles are localized on one side of the anisotropic conductive film, and the particle density of the conductive particles in the anisotropic conductive film is 5000 pieces/mm2 or more and 50000 pieces/mm2 or less. use it,
The connection process is,
The anisotropic conductive film is disposed between the circuit component and the substrate so that the one surface side faces the substrate, 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. A method of manufacturing a bonded structure, comprising a temporarily fixing step of press-fitting the protruding electrode into the anisotropic conductive film so that . The method of claim 1, wherein in the temporarily fixing step, the protruding electrode is press-fitted into the anisotropic conductive film so that the distance between the surface of the protruding electrode and the surface of the substrate is 100% or less of the average particle diameter of the conductive particles. , method of manufacturing a connected structure. The method according to claim 1 or 2, wherein in the temporarily fixing step, the protruding electrode is formed into the anisotropic conductive electrode such that the distance between the surface of the protruding electrode and the surface of the substrate is less than 100% of the average particle diameter of the conductive particles. A method of manufacturing a bonded structure that is press-fitted into a film. The method according to any one of claims 1 to 3, wherein the connecting step is performed after the temporary fixing step by heating and further press-fitting the protruding electrode into the anisotropic conductive film, thereby connecting the protruding electrode and the substrate to the above-mentioned A method of manufacturing a connected structure, further comprising a main fixing step of electrically connecting through conductive particles.