JP5636156B2 - Method of applying anisotropic conductive adhesive film resin solution - Google Patents

Description

  The present invention relates to a technique for applying a viscous resin liquid on a long sheet substrate, and particularly to a technique for applying a highly viscous resin liquid.

  Conventionally, when a resin film is formed by applying a viscous resin on a long sheet substrate, the resin is applied on the sheet substrate conveyed by a roll-shaped conveying means, and then a coater roll or a doctor knife is used. Thus, the thickness of the resin is adjusted (see, for example, Patent Document 1).

However, in such a conventional technique, particularly when a high-viscosity resin is used, there may be a variation in film thickness at the time of application, and there is a demand for improvement.
JP 2005-336447 A

  The present invention has been made in order to solve such problems of the conventional technology, and an object of the present invention is to provide a resin liquid coating technique capable of making the film thickness uniform during coating. It is in.

In order to achieve the above object, the present invention provides a transport roller for supporting and transporting a sheet substrate on which an anisotropic conductive adhesive film resin solution containing conductive particles in a binder is applied, and the transport roller. A metal doctor knife disposed in close proximity to the blade, a resin solution supply means for supplying the anisotropic conductive adhesive film resin solution into a gap between the transport roller and the blade portion of the doctor knife, and a blade portion of the doctor knife Based on the result obtained by the temperature sensor, the heater for heating the blade portion of the doctor knife, the temperature sensor for detecting the temperature of the blade portion of the doctor knife, An anisotropic conductive adhesive film resin liquid coating method using a coating device having a temperature control means for controlling the operation of the heater, the transport roller and the document -While supplying the anisotropic conductive adhesive film resin solution to the gap between the blade portion of the knife and operating the conveying roller while heating the blade portion of the doctor knife, the anisotropic conductive adhesive film resin solution is It is a coating method of the anisotropic conductive adhesive film resin liquid which has the process of contacting the blade part of the said doctor knife and conveying the said sheet | seat base material.
In this invention, the blade part of the said doctor knife can also be heated to 35 to 50 degreeC .

In the case of the present invention, the conveying roller is operated while heating the blade portion of the doctor knife by the heater provided in the body portion integrally formed with the blade portion of the metal doctor knife, and the conductive particles are placed in the binder. by conveying the sheet substrate by contacting the anisotropic conductive adhesive film resin solution containing the blade portion of the doctor knife, the viscosity of the resin solution suitable for coating in a short time rapidly decreases upon application together becomes viscosity, the resin liquid fluidity is improved, and as a result, it is possible to improve by preventing unevenness of thickness film thickness uniformity upon coating.

Further, in the present invention, the temperature of the anisotropic conductive adhesive film resin liquid can be kept constant during application by detecting the temperature of the blade of the doctor knife and controlling the operation of the heater based on the result. Therefore, the surface roughness of the coating film can be reduced.
Particularly in the present invention, in order to contact a straight Sejju fat liquid to the blade portion of the doctor knife, it is possible to maintain the temperature of the tree butter liquid accurately constant, thereby making it possible to reduce the surface roughness of the coating film .

According to the present invention, it is possible to apply a resin liquid having a uniform film thickness and a small surface roughness. As a result, according to the present invention, a high-quality anisotropic conductive adhesive film having a uniform film thickness can be provided.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
The present invention is, for example, an adhesive such as an insulating adhesive film in which an adhesive layer is formed on a sheet substrate, and an anisotropic conductive adhesive film in which conductive particles are dispersed in the insulating adhesive. It is suitable for a conductive film.

FIG. 1 is a front view showing an external configuration of an embodiment of a coating apparatus according to the present invention, and FIGS. 2 and 3 are diagrams for explaining the operation of the present invention.
As shown in FIG. 1, the coating apparatus 1 of this Embodiment has the conveyance roller 3 which supports and conveys the sheet | seat base material 2 mentioned later.

  The transport roller 3 is made of, for example, a metal such as stainless steel, and is configured to rotate in a predetermined direction (here, a clockwise direction) by a drive motor (not shown).

  For example, a series of long sheet base materials 2 made of, for example, PET are bridged on the conveying roller 3, and the sheet base material 2 is further looped around a winding roller (not shown). The upper portion 2a of the sheet base 2 is horizontally conveyed in a direction away from the conveying roller 3 (hereinafter referred to as “sheet conveying direction”).

A doctor knife 4 is provided above the transport roller 3.
The doctor knife 4 is formed by integral molding using, for example, a metal such as stainless steel, and the blade portion 4 a is disposed close to the sheet base material 2 on the conveying roller 3.

In the case of the present invention, although not particularly limited, from the viewpoint of the thin film coating technology, the gap between the sheet base material 2 on the conveying roller 3 and the blade portion 4a of the doctor knife 4 is set to 10 to 20 μm. It is preferable to set.
Resin liquid supply means 5 is provided on the upstream side of the conveying roller 3 and the doctor knife 4 in the sheet conveying direction.

This resin liquid supply means 5 is connected to a resin liquid source (not shown), and the tip of the hose-shaped supply part 6 is in the vicinity of the gap between the sheet base material 2 on the conveying roller 3 and the blade part 4 a of the doctor knife 4. Is arranged. Then, a coating resin solution (anisotropic conductive adhesive film resin solution) 7 is discharged from the tip of the supply unit 6.

In the case of the present invention, although not particularly limited, the film thickness is uniform and the surface roughness is high with respect to the high-viscosity coating resin solution 7, particularly 50 to 120 Pa · s coating resin solution 7. A resin solution having a small degree can be applied.
Examples of such a coating resin liquid 7 include those using a binder containing an epoxy resin and an acrylic resin.

  In the present embodiment, for example, an arrangement space 4b is formed inside the doctor knife 4, and a resistance heating type heater 8 is provided in the arrangement space 4b, for example. The heater 8 is connected to temperature control means 9 having, for example, a computer.

On the other hand, a temperature sensor 10 for detecting the temperature of the blade portion 4a is provided at a portion of the blade portion 4a of the doctor knife 4. The temperature sensor 10 is connected to the temperature control means 9 described above.
In the present embodiment having such a configuration, for example, the heater 8 is first operated to heat the blade portion 4a of the doctor knife 4 to a predetermined temperature.

  And as shown in FIG. 1, while discharging the resin liquid 7 for coating from the front-end | tip part of the supply part 6, and rotating the conveyance roller 3 clockwise, the upper part 2a of the sheet base material 2 is made into a sheet | seat. Transport in the transport direction.

  As a result, as shown in FIGS. 2 and 3, a liquid pool 7a is formed on the upstream surface portion of the conveying roller 3 and the doctor knife 4 in the sheet conveying direction, and further by rotating the conveying roller 3 in the same direction, The coating resin liquid 7 comes into contact with the blade part 4a of the doctor knife 4 and is regulated to a predetermined thickness, whereby the coating film 20 is formed.

  During this coating process, the temperature of the blade 4a of the doctor knife 4 is detected by the temperature sensor 10, and the operation of the heater 8 is controlled by the temperature control means 9 based on the result obtained by the temperature sensor 10.

In the case of the present invention, although not particularly limited, from the viewpoint of surely preventing the occurrence of coating unevenness and reducing the surface roughness of the coating film 20, the temperature of the blade portion 4a of the doctor knife 4 is set to be low. It is preferable to keep it constant.
Specifically, it is preferable to control the temperature of the blade part 4a of the doctor knife 4 so as to be kept constant in the range of 35 ° C. to 50 ° C., more preferably 40 ° C. to 50 ° C.

  As described above, according to the present embodiment, the conveying roller 3 is rotated while the blade portion 4a of the doctor knife 4 is heated, and the coating resin liquid 7 is brought into contact with the blade portion 4a of the doctor knife 4. By conveying the sheet base material 2, the viscosity of the coating resin solution 7 rapidly decreases during coating, and the viscosity becomes suitable for coating in a short time, and the fluidity of the coating resin solution 7 is improved. As a result, it is possible to prevent the unevenness of the film thickness at the time of application and improve the film thickness uniformity.

  Furthermore, by detecting the temperature of the blade portion 4a of the doctor knife 4 and controlling the operation of the heater 8 based on the result, the temperature of the coating resin liquid 7 can be kept constant during application. The surface roughness of the coating film 20 can be reduced.

  In particular, in this embodiment, since the coating resin liquid 7 is in direct contact with the blade portion 4a of the doctor knife 4, the temperature of the coating resin liquid 7 can be kept constant with high accuracy, whereby the coating film 20 The surface roughness of can be reduced.

The present invention is not limited to the above-described embodiment, and various changes can be made.
For example, in the above-described embodiment, the doctor knife 4 is disposed above the transport roller 3, but the present invention is not limited to this, and the vertical relationship between the transport roller 3 and the doctor knife 4 is reversed. Is also possible.

  Examples of the present invention will be described below in detail together with comparative examples.

[Preparation of coating resin solution]
As binder, epoxy resin (EP828, Japan Epoxy Resin Co., Ltd.) 30 parts by weight, acrylic resin (Toa Gosei Co., Ltd. TO-1463) 30 parts by weight, epoxy curing agent (Asahi Kasei Co., Ltd. HX3941HP) 25 parts by weight, conductive particles (Sekisui Chemical) 10 parts by weight of AUL (manufactured by AUL Co., Ltd .: average particle diameter 5 μm) was dissolved and mixed with a mixer using toluene as a solvent to prepare a paste-like resin resin for coating.
The viscosity of this coating resin solution was 60 Pa · s.

<Example 1, Comparative Examples 1-3: Doctor knife heating>
On the PET film with a thickness of 50 μm using the coating apparatus shown in FIG. 1 while maintaining the temperature of the blade of the doctor knife at 30 ° C., 35 ° C., 40 ° C., 45 ° C., 50 ° C., 55 ° C., 60 ° C. Then, the above-mentioned coating resin solution was applied to form an anisotropic conductive adhesive film.
In this case, the distance between the PET film surface and the blade of the doctor knife was set to 30 μm.

[Coating appearance observation]
The appearance of each anisotropically conductive adhesive film was evaluated by visually observing the reflection state of the lighting device above the coating film to evaluate the unevenness of the film thickness. The results are shown in Table 1.

  Here, “◎” indicates that the lighting device can be clearly recognized by the reflection, “○” indicates that the lighting device has been recognized by the reflection, “△” indicates that the lighting device cannot be recognized by the reflection, The case where the film thickness was confirmed to be uneven was designated as “x”.

[Surface roughness measurement]
Using a microscope with a distance measurement function (Keyence VHX-200), set the magnification to 300 times, for example, as shown in FIG. 4, measure the roughness pitch between the convex tops of each anisotropic conductive adhesive film This was defined as the surface roughness. The results are shown in Table 1.
It is widely known that there is a positive correlation between the roughness pitch P and the coating thickness T shown in FIG.

<Comparative Examples 4 to 10: Conveying roller heating>
Using the coating apparatus shown in FIG. 1, the above coating resin is applied on the PET film while maintaining the temperature of the transport roller at 30 ° C., 35 ° C., 40 ° C., 45 ° C., 50 ° C., 55 ° C., 60 ° C. The solution was applied to form an anisotropic conductive adhesive film.

  In this case, the interval between the PET film surface and the blade portion of the doctor knife was set in the same manner as in the case of doctor knife heating.

[Coating appearance observation]
The appearance of each anisotropic conductive adhesive film was observed and evaluated by the same method as in the case of doctor knife heating. The results are shown in Table 2.

[Surface roughness measurement]
The roughness pitch between the convex portions of each anisotropic conductive adhesive film was measured by the same method as in the case of doctor knife heating, and this was defined as the surface roughness. The results are shown in Table 2.

<Comparative Examples 11-17: Resin liquid heating for coating>
Using the coating apparatus shown in FIG. 1, the temperature of the coating resin solution is directly heated to 30 ° C., 35 ° C., 40 ° C., 45 ° C., 50 ° C., 55 ° C., 60 ° C. with a heater, and then supplied. An anisotropic conductive adhesive film was formed thereon.
In this case, the interval between the PET film surface and the blade portion of the doctor knife was set in the same manner as in the case of doctor knife heating.

[Coating appearance observation]
The appearance of each anisotropic conductive adhesive film was observed and evaluated by the same method as in the case of doctor knife heating. The results are shown in Table 3.

[Evaluation results]
<Doctor knife heating>
As can be seen from Table 1, with respect to Examples 1 to 4 in which the temperature of the blade portion of the doctor knife was set to 35 to 50 ° C., the coating appearance was good and coating without uneven coating could be performed.
On the other hand, in the case of Comparative Example 1 where the temperature of the blade portion of the doctor knife was low (30 ° C.), no improvement was observed in the coating appearance.

Moreover, about the comparative examples 2 and 3 whose temperature of the blade part of a doctor knife is high (55 degreeC, 60 degreeC), the nonuniformity (horizontal stripe) of the periodic film thickness generate | occur | produced.
On the other hand, the surface roughness was 60 to 130 μm in the case of Examples 1 to 4, and a result smaller by 50 μm or more than that in Comparative Examples 1 to 3 was obtained.

<Conveying roller heating>
As is apparent from Table 2, even when the temperature of the conveying roller was changed between 30 and 60 ° C., no improvement was observed in the appearance of coating. In particular, in Comparative Example 6 in which the temperature of the conveying roller was set to 40 ° C. or higher, periodic unevenness (lateral stripes) occurred in the film thickness.
The cause of this is presumed to be that the rotating shaft portion and the outer peripheral portion of the conveying roller expand due to heat.

  Further, the surface roughness is at least 70 μm or more larger than those in Examples 1 to 4, and in the range of 35 ° C. to 50 corresponding to Examples 1 to 4, the results exceed 100 μm with respect to Examples 1 to 4. became.

<Resin liquid heating for coating>
As is apparent from Table 2, even when the temperature of the coating resin solution was changed between 30 to 60 ° C., no improvement was observed in the coating appearance.
Furthermore, dew condensation occurs in the heated portion of the coating resin solution, and moisture may be mixed into the coating resin solution, causing a problem in practical use.
From the above results, the effect of the present invention could be confirmed.

It is a front view which shows the external appearance structure of embodiment of the coating device which concerns on this invention. It is a figure for demonstrating the effect | action by this invention (the 1). It is a figure for demonstrating the effect | action by this invention (the 2). It is a figure for demonstrating the measuring method of surface roughness.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Coating apparatus 2 ... Sheet base material 3 ... Conveying roller 4 ... Doctor knife 4a ... Blade part 5 ... Resin liquid supply means 6 ... Supply part 7 ... Resin liquid for coating (anisotropic conductive adhesive film resin liquid)
8 ... Heater 9 ... Temperature control means 10 ... Temperature sensor

Claims (2)

A transport roller for supporting and transporting a sheet substrate on which an anisotropic conductive adhesive film resin solution containing conductive particles in a binder is applied;
A metal doctor knife arranged close to the conveying roller;
A resin liquid supply means for supplying the anisotropic conductive adhesive film resin liquid to the gap between the conveying roller and the blade of the doctor knife;
A heater that is provided in a body portion formed integrally with the blade portion of the doctor knife, and that heats the blade portion of the doctor knife;
A temperature sensor for detecting the temperature of the blade of the doctor knife;
An anisotropic conductive adhesive film resin liquid coating method using a coating apparatus having a temperature control means for controlling the operation of the heater based on the result obtained by the temperature sensor,
While supplying the anisotropic conductive adhesive film resin liquid to the gap between the conveying roller and the blade portion of the doctor knife, operating the conveying roller while heating the blade portion of the doctor knife, the anisotropic conductive A method for applying an anisotropic conductive adhesive film resin solution comprising a step of bringing the sheet substrate into contact with an adhesive film resin solution in contact with the blade portion of the doctor knife. The method for applying an anisotropic conductive adhesive film resin solution according to claim 1, wherein the blade portion of the doctor knife is heated to 35 ° C. or more and 50 ° C. or less .

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