JP3082697B2 - Anisotropic conductive film sticking method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for attaching an anisotropic conductive film, and more particularly to an anisotropic conductive film connecting medium between a driver IC terminal connected to a liquid crystal panel of a liquid crystal display device and a printed circuit board electrode terminal. The present invention relates to a method and an apparatus for attaching a conductive film.

[0002]

2. Description of the Related Art Conventional anisotropic conductive films (hereinafter referred to as AC
5A, the bonding apparatus includes a thermocompression bonding head 6, a printed circuit board receiving table 5, and a carrier film peeling mechanism 8.

[0003] As shown in FIG.
m ACF2 and carrier film 3 having a thickness of 0.07 mm
ACF2 of an anisotropic conductive tape material (hereinafter, referred to as a tape material) to which a printed circuit board 4 (hereinafter, referred to as PWB) is attached.
). Next, as shown in FIG. 5B, the thermocompression bonding head 6 is lowered, and after performing thermocompression bonding for a predetermined time, it is raised. After the thermocompression bonding head 6 is raised, the fixing claws 9 of the carrier film peeling mechanism 8 grip the carrier film 3, and the carrier film peeling mechanism 8 rises (FIG. 5C). As a result, an angle θ is generated between the ACF 2 and the carrier film 3, and a force in the separation direction acts on the ACF 2.
The carrier film 3 is peeled off from the CF 2 (FIG. 5).
(D)). According to this method, the separation resistance between the carrier film 3 and the ACF 2 when the carrier film 3 is peeled off is PWB 4 and A.
The inconvenience that ACF2 is peeled off from PWB4 due to an increase in the adhesion force of CF2 is likely to occur.

[0004] As a second conventional example, Japanese Patent Application Laid-Open No. 6-28
There is one disclosed in Japanese Patent No. 1945. As shown in FIG. 6, the pressing surface of the pressure bonding head 102 has a concave portion 102a.
Is provided, and the anisotropic conductive tape 104 is pressed.

[0005] A method is disclosed in which, when an uncompressed portion of the anisotropic conductive tape 104 that is not press-fitted corresponding to the concave portion 102a is pulled up by the peeling claw 106, the non-pressed portion is peeled off together with the cover film 105.

A third prior art is disclosed in Japanese Patent Laid-Open No. 6-60 / 1994.
There is one disclosed in Japanese Patent Application Publication No. This is performed by pressing the carrier film 307 and the ACF 306 with a heated thermocompression roller 316 as shown in FIG.
Press on 1. The carrier film 307 is taken up by the ACF take-up reel 309 while the roller 316 is advanced. Thus, the ACF 306 can be attached without being separated from the liquid crystal substrate 301.

A fourth conventional example is disclosed in Japanese Patent Application Laid-Open No. 7-9 / 1995.
In Japanese Patent No. 2436, as shown in FIG. 8, the carrier film 202 and the ACF 204 are separated before the pressure bonding, and the ACF is fixed by the fixed block head 213.
A technique is disclosed in which the ACF 204 is cut at 216b, the ACF 204 is suctioned and conveyed by the suction block head 215, and attached to a liquid crystal panel or the like.

[0008]

The problem with the first conventional example described with reference to FIG. 5 is that when the carrier film 3 is pulled up after the thermocompression bonding of the ACF 2, the ACF 2 is peeled off from the PWB 4 together with the carrier film 3. Is that it may be done. When the ACF 2 is separated from the PWB 4, there is no ACF 2 serving as a connection medium, so that electrical continuity cannot be obtained and an open failure occurs. The method of correcting the open defect is to remove the ACF2 stuck on the PWB4,
Although F2 is adhered, it is not easy to cleanly remove the conductive particles of ACF2 that have entered the gap between the terminals of PWB4, which is a troublesome rework.

[0009] The reason why the ACF2 is separated from the PWB4 is as follows.
Due to factors such as a decrease in adhesive strength due to contamination of the surface of the PWB 4, an adhesive strength of the ACF 2, and a variation in a peeling treatment between the carrier film 3 and the ACF 2, the adhesive strength between the ACF 2 and the carrier film 3 may be stronger than the adhesive strength between the ACF 2 and the PWB 4. Because there is.

Also, in the second conventional example disclosed in Japanese Patent Application Laid-Open No. Hei 6-281945, the adhesion force between the anisotropic conductive tape 104 and the liquid crystal substrate 101 varies naturally. In this method, the cover film 105 is lifted to separate the cover film 105 from the anisotropic conductive tape 104. Therefore, the anisotropic conductive tape 1 is basically similar to the above-described method.
When the cover film 105 and the liquid crystal substrate 101 are separated from each other, the cover film 105 is fixed only by the adhesive force between the anisotropic conductive tape 104 and the liquid crystal substrate 101. The problem that the conductive tape 104 peels off is not solved.

Further, in the third conventional example disclosed in Japanese Patent Application Laid-Open No. 6-6019, a portion where the ACF 306 and the carrier film 307 can be pressed by the roller 316 is a roller 31.
There is only contact with 6. Carrier film 3
07 is removed from the ACF 306 (as can be seen from FIG. 7) at a position displaced from the contact point. Because of such a state, the peeling conditions are the same as those of the above-described method. Therefore, the problem that the anisotropic conductive tape is peeled off cannot be solved.

Further, in the fourth conventional example disclosed in Japanese Patent Application Laid-Open No. Hei 7-92436, there is a problem that the suction block head 215 needs to be replaced when the length of the ACF 204 is changed. There is also a problem that the ACF 204 is pulled directly to control the length of the drawer. This is because the ACF 204 is a material that expands in physical properties as compared with the carrier film 202, and thus has a large variation in length.

An object of the present invention is to provide a method of attaching an anisotropic conductive film to a printed circuit board, which can more reliably attach the anisotropic conductive film to the printed circuit board, and reduce an open defect and repair work, and an apparatus used therefor. It is in.

[0014]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for attaching an anisotropic conductive film to a printed circuit board having at least one through-hole, the carrier film having an anisotropic conductive film attached thereto. The step of pressing the anisotropic conductive film of the anisotropic conductive film to close the through hole and thermocompression bonding,
Removing the carrier film while sucking and fixing the anisotropic conductive film to the printed circuit board using the through hole.

Further, the anisotropic conductive film sticking apparatus of the present invention comprises: a printed circuit board receiving base having a suction hole connected to a vacuum source on an upper surface;
Thermocompression bonding means for placing a printed circuit board having a through hole with the through hole aligned with the suction hole, and overlaying and pressing an anisotropic conductive tape material thereon; and And a carrier film peeling mechanism for peeling the carrier film of the anisotropic conductive tape material from the anisotropic conductive film.

In this case, a vacuum sensor can be provided in a vacuum system connecting the suction hole and the vacuum source. Further, a tape transport means for arranging the anisotropic conductive tape material above the printed circuit board pedestal and intermittently moving the carrier film is provided, and the carrier film peeling moving in a direction away from the printed circuit board pedestal by grasping the carrier film. A mechanism can be located downstream from the printed circuit board cradle in the tape transport path.

The force applied to the anisotropic conductive film when the carrier tape of the anisotropic conductive tape material thermocompressed to the printed circuit board is peeled off can be offset by the attraction force to the printed circuit board.

[0018]

FIG. 1 is a plan view showing a main part of a first embodiment of an anisotropic conductive film sticking apparatus according to the present invention.
2A and 2B are a cross-sectional view showing a state where a printed circuit board and the like are mounted on the printed circuit board receiving stand 5 of FIG. 1 and a plan view of the printed circuit board receiving stand 5, respectively.

In this embodiment, a printed circuit board receiving stand 5, a thermocompression bonding head 6, and an anisotropic conductive tape material 1 are arranged above the printed circuit board receiving stand 5, and the tape is transported intermittently. Means and Carrier Film Peeling Mechanism 8
And

The printed circuit board receiving table 5 has three suction holes 30-1 each having a diameter of 2 mm on each short side of a table or box upper plate 5-1 (a rectangular one is exemplified). I have. This suction hole connects the tip of the vacuum pipe 30 to the upper plate 5.
-1 and is fixed to the upper plate by welding or other appropriate means. A total of six vacuum pipes are used for the vacuum sensor 16 and the vacuum source unit 15.
(Such as a vacuum pump).

A heater 17 is embedded in the thermocompression bonding head 6, and is controlled to a predetermined temperature by a temperature controller 18. The thermocompression bonding head 6 is connected to a head driving unit 7 such as a motor by a driving shaft 7-1 so that the distance between the thermocompression head 6 and the printed circuit board receiving table 5 can be changed.

The tape conveying means is an anisotropic conductive tape material 1
(For example, Anisorm, manufactured by Hitachi Chemical Co., Ltd., in which ACF2 having a thickness of 0.045 mm is bonded to a carrier film 3 having a thickness of 0.07 mm), and a supply reel having tension in a direction opposite to the rotation direction. 10, an ACF cutting section 11 for cutting two ACFs 2 along the conveying path of the anisotropic conductive tape material 1 by cutting two lines, and an ACF after cutting.
An ACF peeling unit 12 for peeling the ACF between the two cutting lines 2 from the carrier film 3 with an adhesive tape, a tape feeding mechanism 13, and a collecting nozzle 14 for sucking the carrier film 3 with a vacuum cleaner or the like. Have. Further, after the PWB receiving table 5 in the tape transport path is arranged, a carrier film peeling mechanism 8 for pulling up the carrier film 3 while holding the carrier film 3 with a pair of fixing claws 9 is inserted.
The tape feed mechanism 13 includes an ACF cutting unit 11, an ACF
It has a counter (not shown) for controlling the operation timing of the peeling section 12, the operation timing of the thermocompression bonding head 6, the head drive unit 7, and the stop position (timing) of the anisotropic conductive tape material with respect to the PWB 4.

Next, one embodiment of the anisotropic conductive film sticking method of the present invention will be described together with the operation of the above-described anisotropic conductive film sticking apparatus.

First, a rectangular PWB 4 based on a glass epoxy resin having a thickness of 0.8 mm, which is 2 mm from the short side
Is provided with six through-holes 32 having a diameter of 1.5 mm at the position. It is assumed that the center of these through holes and the center of the suction hole 30-1 provided in the PWB receiving table are designed to substantially coincide with each other. Next, this PWB4 is converted to PWB
The pedestal 5 is placed on the upper plate 5-1. Positioning is performed with reference to the outer shape of the PWB 4, and each through-hole 32 is positioned in each of the suction holes 30-1.
So as not to get out of the way. At this time, the PWB 4 is assumed to be fixed by a PWB holding mechanism (not shown). In addition, if the bottom surface of the thermocompression bonding head 6 is, for example, a rectangular shape, a head that is larger than the outer shape of the PWB 4 by 5 mm or more on each side is used.

The anisotropic conductive tape material 1 is unwound from the supply reel 10 and only the ACF 2 is
Cut at 10mm intervals with a piece of cutter
The area of 10 mm cut by the CF peeling section 12 is peeled off from the carrier film 3 by an adhesive tape. This operation is performed every time the anisotropic conductive tape material 1 is fed by the length of the application. As shown in FIG. 3A, the anisotropic conductive tape material 1 is fed at the position of the PWB 4 surface height of 1 mm, and stops at the position where the ACF 2 corresponding to the attached length has entered under the thermocompression bonding head 6. At this time, as shown in FIG. 2, the stop positions have a positional relationship such that both ends of the ACF 2 and the PWB 4 corresponding to the attached length substantially coincide with each other. Next, as shown in FIG.
The thermocompression bonding head 6 heated to 120 ° C. descends, presses the anisotropic conductive tape material 1 on the PWB 4 from the carrier film 3 side with a load of 5 × 10 ⁵ Pa for 4 seconds, and then rises.
At this time, the vacuum source unit 15
Vacuum of × 10 ⁴ Pa enters and suction holes 30 of PWB receiving table 5
ACF is sucked and fixed through the through hole 32 of the PWB 4 with the ACF-1. As a result, the degree of vacuum increases to 5 × 10 ⁴ Pa or less. When the fixing claw 9 of the carrier film peeling portion 8 grips the carrier film 3 and the carrier film peeling mechanism 8 rises, the carrier film 3 and the ACF 2 are separated from each other at an angle θ (FIG. 2C). 3 peels off. At this time, the vacuum sensor 16 functions, and when the ACF 2 is separated from the PWB ^{4, the} degree of vacuum is reduced and the pressure becomes higher than 5 × 10 ⁴ Pa, so that it is possible to detect whether or not the ACF 2 has been separated. When the carrier film peeling mechanism 8 is lowered to the original position and the fixing claw 9 is released, the tape feeding mechanism 13 is driven to convey the anisotropic conductive tape material 1 to the next stop position. This makes it possible to separate the ACF 2 and the carrier film 3 while keeping the ACF 2 adhered to the PWB 4.

As described above, after the ACF 2 is pressure-bonded to the PWB 4, the ACF 2 is vacuum-adsorbed to the PWB 4 to form a cohesive force with the PWB 4 so that the ACF 2 does not lose the force for separating the ACF 2 from the carrier film 3. I am taking the elimination method. Thereby, the ACF peeling defect from PWB at the time of attaching the ACF is reduced, and the productivity is reduced by 7%.
Improved to some degree. Although the suction holes are provided along both short sides of the PWB, they may be provided only on one side. PWB so that the suction hole is closer to the carrier film peeling mechanism 8
Is important. This is because the carrier film is most easily peeled when the carrier film starts to be peeled.

Next, a second embodiment of the anisotropic conductive film sticking apparatus of the present invention will be described.

As shown in FIG. 4, dozens of suction holes 30A-1 are provided at equal pitches in the PWB receiving table 5A and vacuum sensors 16A are connected to the respective vacuum pipes 30A. Each vacuum degree sensor 16A is connected to a vacuum switching valve 31. This valve is connected to the vacuum source unit 15A with one pipe. By providing a plurality of suction holes 30A-1, the PWB 4 itself can be fixed by applying a vacuum to the suction holes 30A-1, and a PWB 4 displacement prevention mechanism such as a PWB holding mechanism becomes unnecessary. Further, the PW is controlled by controlling a vacuum switching valve connected to the suction hole 30A-1.
It is possible to cope with a change in the position of the PWB4 through hole 32 when the length of B4 is changed.

The tape conveying means, the thermocompression bonding means and the carrier film peeling mechanism are not limited to those described above. For example, in a technique disclosed in Japanese Patent Application Laid-Open No. 6-6019, a P-type substrate having a through hole provided in place of the liquid crystal substrate 301 is disclosed.
Using WB, it can be mounted on a PWB receiving table provided with a suction hole. However, the attachment of the ACF and the peeling of the carrier film progress simultaneously, and the degree of vacuum changes accordingly. In this case as well, the end of ACF attachment can be detected by a change in the degree of vacuum. Further, since the position of the thermocompression bonding means (thermocompression roller 316) and the position of the carrier film are controlled to perform the sticking and peeling at the same time, the carrier film peeling mechanism is used as both the thermocompression bonding means and the tape transport means. it can.

[0030]

[Effects of the Invention] The effects of the present invention are as follows.
ACF peeling failure from the surface is reduced. As a result, the number of correction steps that occur when ACF attachment fails can be reduced, and productivity can be improved.

The reason is that, by fixing at least the end of the ACF on the carrier film peeling start side by local vacuum suction, it is possible to obtain an adhesive force between the PWB and the ACF which is stronger than the adhesiveness between the carrier film and the ACF. Because.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of an anisotropic conductive film sticking apparatus according to the present invention.

2 is an enlarged longitudinal sectional view (FIG. 2 (a)) of the periphery of a PWB receiving portion of FIG. 1 and a plan view of the PWB receiving portion (FIG. 2);
(B)).

FIGS. 3A to 3C are plan views separately illustrating steps (a) to (c) for describing an embodiment of the anisotropic conductive film sticking method of the present invention.

FIG. 4 is a plan view showing a second embodiment of the anisotropic conductive film sticking apparatus of the present invention.

FIGS. 5A to 5C are views for explaining a first conventional example.
FIG. 4D is a plan view illustrating the process in order separated from FIG.

FIG. 6 is a plan view showing a second conventional example.

FIG. 7 is a plan view showing a third conventional example.

FIG. 8 is a plan view showing a fourth conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anisotropic conductive tape material 2 Anisotropic conductive film (ACF) 3 Carrier film 4 Printed circuit board (PWB) 5, 5A PWB receiving stand 6 Thermocompression bonding head 7 Head drive unit 8 Carrier film peeling mechanism 9 Fixed nail 10 Supply Reel 11 ACF cutting unit 12 ACF peeling mechanism 13 Tape feeding mechanism 14 Recovery nozzle 15, 15A Vacuum source unit 16, 16A Vacuum degree sensor 17 Heater 18 Temperature controller 30, 30A Vacuum piping 30-1, 30A-1 Vacuum switching valve 31 Vacuum Switching valve 32 Through hole 102 Crimping head 102a Recess 104 Anisotropic conductive tape 105 Cover film 106 Peeling claw 202 Carrier film 204 ACF 213 Fixed block head 215 Suction block 216a, 216b Cutter 301 Liquid crystal substrate 06 ACF 307 carrier film 316 thermocompression bonding roller 324 roller

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G09F 9/00 G02F 1/1345 H05K 3/20

Claims (4)

(57) [Claims] 1. An anisotropic conductive tape material of an anisotropic conductive tape having a carrier film bonded to a printed circuit board having at least one through hole, and pressed against the through hole. A step of thermocompression bonding, and a step of peeling off the carrier film while sucking the anisotropic conductive film using the through holes and fixing the film to the printed circuit board. Pasting method. 2. A printed circuit board receiving base having a suction hole connected to a vacuum source on an upper surface thereof, and a printed circuit board having a through hole in the printed circuit board receiving base. Thermocompression bonding means for placing the anisotropic conductive tape material on top of the anisotropic conductive tape material and pressing the carrier film of the anisotropic conductive tape material thermocompressed to the printed circuit board from the anisotropic conductive film An anisotropic conductive film sticking device, comprising: a carrier film peeling mechanism for peeling. 3. The anisotropic conductive film sticking apparatus according to claim 2, further comprising a vacuum sensor in a vacuum system connecting the suction hole and the vacuum source. 4. An anisotropic conductive tape material is disposed above a printed circuit board receiving table, and tape transport means for intermittently moving the tape material is provided, and the carrier film is moved in a direction away from the printed circuit board receiving table by holding a carrier film. 4. The anisotropic conductive film sticking apparatus according to claim 2, wherein the carrier film moving mechanism is disposed downstream from the printed circuit board receiving stand in the tape transport path.