JP2024048290A - Pressure bonding device - Google Patents

Abstract

An object of the present invention is to provide a pressure bonding device for an image display panel that is capable of pressure bonding an image display panel and an FPC board with good quality even when the length dimension of the tip portion of the FPC board is large.
[Solution] This pressure bonding device includes a pressure bonding head 301 that pressure-bonds an electrode terminal portion 202 provided on the surface of an FPC board 201 to an electrode terminal portion 102 provided on the surface of an image display panel 101 formed by bonding a first substrate 103 and a second substrate 104 together, the pressure bonding head 301 having a side and a bottom surface, and the side surface is provided with an suction hole 303 that holds the tip portion of the FPC board 201, and the pressure bonding head 301 pressure-bonds the electrode terminal portion 202 of the FPC board 201 to the electrode terminal portion 102 of the image display panel 101 by using the bottom surface while holding the tip portion of the FPC board 201 by the suction hole 303.
[Selected figure] Figure 4

Description

The present invention relates to a crimping and joining device.

When manufacturing an image display device, in order to obtain electrical continuity in the image display panel (for example, a liquid crystal display panel or an organic EL panel) used in the image display device, a pressure bonding method is used in which electrode terminals formed on one substrate of the image display panel are bonded to electrode terminals of a flexible substrate (hereinafter, FPC substrate) by thermocompression bonding via an anisotropic conductive film (hereinafter, ACF).

Figure 6 is a side view showing an example of a conventional pressure bonding device. In a conventional general pressure bonding method, first, the image display panel 101 is placed on a heat dissipating pressure bonding stage 304, ACF 401 is supplied so that the electrode terminal portion 102 of the image display panel 101 is covered, and the ACF 401 is attached to a predetermined position, and then the FPC board 201 is supplied on the ACF 401, and the terminal electrode portion 202 (see FIG. 3 described later) of the FPC board 201 and the electrode terminal portion 102 of the image display panel are overlapped. Next, the pressure bonding head 301 is heated, and when a sufficient temperature is obtained, the pressure bonding head 301 is lowered and pressed against each overlapped electrode terminal portion through a protective sheet (not shown), thereby performing pressure bonding of each electrode terminal portion.

7A and 7B are diagrams showing an image display panel in the prior art, in which (a) is a perspective view showing a state before the FPC board is pressure-bonded to the image display panel, and (b) is a perspective view showing a state after the FPC board is pressure-bonded to the image display panel. The image display panel 101 is formed by bonding a first substrate 103 and a second substrate 104 at appropriate positions with resin or the like, with the electrode surfaces of the substrates facing each other. For example, when the image display panel 101 is a liquid crystal display panel, liquid crystal 106 (see FIG. 6) is injected into the gap between the first substrate 103 and the second substrate 104. In addition, as shown in FIG. 7A, the image display panel 101 is configured such that the outer periphery of one side on which the electrode terminals 102 of the first substrate 103 are arranged protrudes outward from the outer periphery of the second substrate 104, and thus a step portion 105 is provided between the outer periphery of the second substrate 104 and the outer periphery of the first substrate 103. As shown in FIG. 7(b), the FPC board 201 is pressure-bonded to the upper surface of the first substrate 103 adjacent to the step portion 105. (See, for example, Patent Document 1.)

JP 2020-166104 A

Figure 8 is a perspective view showing a state in which an FPC board with a large length dimension is pressure-bonded to the electrode terminal portion of an image display panel in the conventional technology. When the length dimension from the electrode terminal portion to the tip of the FPC board 201 is greater than the length dimension of the portion of the image display panel 101 where the first substrate 103 protrudes outward beyond the second substrate 104 as shown in Figure 8, the conventional pressure bonding method has a problem in that the tip of the FPC board 201 interferes with the step portion 105 of the image display panel 101 when the FPC board 201 is pressure-bonded.

The above problems ultimately lead to various problems such as a decrease in the connection position accuracy of the FPC board 201 during pressure bonding, a decrease in the parallelism between the FPC board 201 and the electrode terminal portion 102 of the image display panel, and poor bonding of the electrode terminal portion.

The present invention was made in consideration of the above problems, and aims to provide an image display panel pressure bonding device that can perform high-quality pressure bonding between an image display panel and an FPC board 201 even when the length dimension of the tip of the FPC board is large.

A crimping bonding device including a crimping head that crimps and bonds an electrode terminal portion provided on a surface of an FPC board to an electrode terminal portion provided on a surface of an image display panel formed by bonding a first substrate and a second substrate together, the crimping head having a side surface and a bottom surface, the side surface being provided with a holding portion that holds a tip portion of the FPC board, the crimping head crimps and bonds the electrode terminal portion of the FPC board to the electrode terminal portion of the image display panel by the bottom surface while holding the tip portion of the FPC board by the holding portion.

The crimping head may be a crimping and bonding device that crimps and bonds the electrode terminal portion of the FPC board to the electrode terminal portion of the image display panel with the bottom surface while pressing the FPC board against a corner of a step portion formed between the outer periphery of the first substrate and the outer periphery of the second substrate.

The holding unit may be a pressure bonding device that holds the FPC board by vacuum suction.

According to the present invention, it is possible to perform high-quality pressure bonding between an image display panel and an FPC board.

A flow diagram showing a method for bonding an FPC board to an image display panel by pressure bonding. 1A is a cross-sectional view showing a state before an FPC board is vacuum-adsorbed to a compression head; FIG. 1B is a cross-sectional view showing a state after the FPC board has been vacuum-adsorbed to the compression head; 1 is a top view of an FPC board according to an embodiment of the present invention; 1A is a cross-sectional view showing a state in which an FPC board vacuum-adsorbed to a compression head is transported to the periphery of an image display panel; FIG. 1B is a cross-sectional view showing a state in which the FPC board vacuum-adsorbed to the compression head is being compression-adsorbed to the image display panel; 1A is a perspective view showing an image display panel after an FPC board has been pressure-bonded by a pressure bonding device according to an embodiment of the present invention; FIG. FIG. 1 is a cross-sectional view showing an example of a pressure bonding device according to a conventional technique. 1A is a perspective view showing a state before an FPC board is pressure-bonded to an image display panel according to a conventional technique; FIG. 1B is a perspective view showing a state after the FPC board is pressure-bonded to the image display panel; FIG. 1 is a perspective view showing a state in which an FPC board having a large length is pressure-bonded to an electrode terminal portion of an image display panel in a conventional technique;

Figure 1 is a flow diagram showing a method of bonding an FPC board to an image display panel. Figure 2 is a diagram showing a bonding process in an embodiment of the present invention, where (a) is a cross-sectional view showing a state before the FPC board is vacuum-adsorbed to the bonding head, and (b) is a cross-sectional view showing a state after the FPC board is vacuum-adsorbed to the bonding head. Figure 3 is a top view of an FPC board in an embodiment of the present invention. Figure 4 is a diagram showing a bonding process in an embodiment of the present invention, where (a) is a cross-sectional view showing a state in which the FPC board vacuum-adsorbed to the bonding head is transported to the periphery of the image display panel, and (b) is a cross-sectional view showing a state in which the FPC board vacuum-adsorbed to the bonding head is bonded to the image display panel. Figure 5 is (a) a perspective view and (b) a side view showing an image display panel after the FPC board has been bonded to the image display panel by a bonding device in an embodiment of the present invention. Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The bonding apparatus according to the embodiment of the present invention includes a bonding head 301 as shown in FIG. 2(a) and a bonding stage similar to the bonding stage 304 as shown in FIG. 6. The side wall of the bonding head 301 is provided with a vacuum line and suction holes 303 for vacuum-adsorbing the FPC board 201. In addition, a heater 302 is provided at the bottom of the bonding head 301 for thermally bonding the image display panel 101 and the FPC board 201 via the ACF 401.

As shown in FIG. 3, in the FPC board 201 in the embodiment of the present invention, the electrode terminal portion 202 is provided at a position closer to the center in the longitudinal direction than the tip of the FPC board 201, and the length dimension from the tip of the FPC board 201 to the electrode terminal portion 202 is greater than the length dimension of the protruding portion of the first substrate 3 of the image display panel 101 (the portion protruding outward from the second substrate 4). Therefore, when performing compression bonding using a conventional compression bonding device, the step portion 105 of the image display panel 101 may interfere with the FPC board 201 during compression bonding, and proper bonding may not be performed. In contrast, in the embodiment of the present invention, when the FPC board 201 is compression bonded to the image display panel 101, a compression bonding device equipped with a compression head as shown in FIG. 2 is used, and each process is performed according to the flow as shown in FIG. 1, for example.

First, in the image display panel manufacturing process G1 shown in FIG. 1, an image display panel 101 is manufactured. The image display panel 101 is, for example, similar to the image display panel 101 shown in FIG. 7.

Next, in the ACF pasting process G2 shown in FIG. 1, ACF 401 (see FIG. 6) is supplied to and pasted on the terminal electrode portion 102 of the image display panel. Specifically, first, as a preparation process, the pressure bonding device is started, and pre-production inspections such as temperature adjustment and position adjustment of the pressure bonding head 301 are performed in sequence, and the terminal electrode portion 102 of the image display panel 101 and the terminal electrode portion 202 of the FPC board 201 are cleaned. If the ACF 401 is pressure bonded with foreign matter or dirt attached to the terminal electrode portion, the bond will be weak and the bonding surface will peel off. After cleaning the terminal electrode portion, the parts necessary for the pressure bonding are replenished to a specified parts loader, and a tray for storing the pressure bonded image display panel 101 is placed on the unloader side. Then, the position of the image display panel 101 is adjusted so that the pixel portion 107 (see FIG. 6) fits into the opening of the recess formed in the pressure bonding stage 304, and the image display panel 101 is placed on the pressure bonding stage 304. Both the bonding stage 304 and the bonding head 301 can be moved in the x-axis, y-axis, and z-axis directions by air cylinders.

After these preparation steps are completed, the ACF 401 cut to the shape required for pressure bonding is transported from the parts loader and attached to cover the terminal electrode portion 102 of the image display panel 101. The pressure bonding head 301 moves to the supply tray of the FPC board 201, rotates 90 degrees so that the suction hole 303 contacts the back surface of the FPC board 201 as shown in FIG. 2(a), descends from the top of the FPC board 201, and detects whether it is in contact with the FPC board 201 with a sensor or the like. After it is detected that the pressure bonding head 301 is in contact with the FPC board 201, the suction hole 303 of the pressure bonding head 301 sucks in air, and the FPC board 201 is fixed by suction. At the same time, the heater 302 is operated to start heating the pressure bonding head 301. After the FPC board 201 is fixed by suction, the bonding head 301 rises and rotates again 90° so that the bonding surface (bottom surface) of the bonding head 301 faces downward as shown in FIG. 2B and so that the FPC board 201 is perpendicular to the image display panel 101, and the FPC board 201 is transported near the bonding stage 304. During this transport, the positions of the terminal electrode portion 102 of the image display panel 101 and the terminal electrode portion 202 of the FPC board 201 are adjusted to be predetermined joining positions. The position at which the FPC board 201 is fixed by suction is adjusted so that the heater 302 and each electrode terminal portion overlap when the bonding head 301 is rotated 90°.

Next, in the temporary bonding step G3 shown in FIG. 1, as shown in FIG. 4(a), the preheated bonding head 301 is moved diagonally from above toward the corner 602 of the step 105 of the image display panel 101, and the FPC board 201 is transported to the upper surface of the first substrate 103 of the image display panel 101. At this time, the bonding head 301 is moved diagonally so that the corner 601 on one side of the bonding head 301 is aligned with the corner 602 of the step 105 of the image display panel 101, and the corners are pressed against each other. When the corner 601 of the bonding head 301 is pressed against the corner 602 of the step 105 of the image display panel 101, the FPC board 201 is arranged in a state bent at approximately 90° so as to match the shape of the corner 601 of the bonding head 301. In this state, heat is applied by the heater 302 mounted on the bonding head 301, and while pressing, the electrode terminal portion 102 of the image display panel 101 and the electrode terminal portion 202 of the FPC board 201 are temporarily bonded via the ACF 401. When attaching the ACF 401, it is preferable to adhere it closely to the substrate surface so that no air bubbles are mixed between each terminal electrode portion and the ACF 401, since this can eliminate concerns about insufficient bonding strength or bonding failure.

Next, in the main pressure bonding process G4 in FIG. 1, the pressure bonding head 301 applies stronger and more uniform pressure to the ACF 401 than during the temporary pressure bonding, and main pressure bonding is performed between the terminal electrode portion 102 of the image display panel 101 and the terminal electrode portion 202 of the FPC board 202. It is desirable that the heat transferred to the ACF 401 be within the range of approximately 160°C to 200°C, which is not transferred to the pixel portion 107 of the image display panel 101. The image display panel 101 that has been main pressure bonded is transported to a storage tray on the unloader side, and the series of processes is completed. This results in an image display panel 1 with the FPC board 201 pressure bonded thereto, as shown in FIG. 5.

The pressure bonding device according to the embodiment of the present invention described above can easily bend the tip of the FPC board 201, thereby suppressing interference between the tip of the FPC board 201 and the step portion 105 of the image display panel 101.

When performing compression bonding, a protective sheet may be placed between the compression head 301 and the FPC board 201, as in conventional technology. The protective sheet is used to prevent warping and thermal deterioration of the FPC board 201 due to heating during compression bonding.

The suction holes 303 formed in the crimping head 301 may be provided in one or more locations, and the shape of the tip of the suction surface is not limited to that of the embodiment, but may be other shapes.

During pressure bonding, when the corners 601 of the pressure bonding head 301 come into contact with the corners 602 of the step portions 105 of the image display panel 101, a member that relieves the stress applied to the step portions 105 may be placed between each corner and the FPC 201.

During pressure bonding, the pressure bonding device may be provided with a cooling function that cools the image display panel 101 using gas or liquid to protect the pixel section 107 from heat.

During crimping, the crimping head 301 moves linearly when the corner 601 of the crimping head 301 butts against the corner 602 of the step portion 105 of the image display panel 101, but this is not limited to this and the operation may be changed as appropriate to suit the specifications.

The method of holding the FPC board 201 on the bonding head 301 is not limited to vacuum suction, but may be, for example, holding by adhesive such as resin or seal, or holding by a mechanical gripping mechanism, etc.

The image display panel 101 is not limited to a liquid crystal display panel, but may be other image display panels such as an organic EL panel.

REFERENCE SIGNS LIST 101 Image display panel 102 Electrode terminal portion of image display panel 103 First substrate 104 Second substrate 105 Step portion 106 Liquid crystal 107 Pixel portion 201 FPC substrate 202 Electrode terminal portion of FPC substrate 301 Pressure bonding head 302 Heater 303 Suction hole 304 Pressure bonding stage 401 ACF (anisotropic conductive film)
601 Corner of the pressure bonding head 602 Corner of the stepped portion of the image display panel

Claims (3)

A pressure-bonding device including a pressure-bonding head that pressure-bonds an electrode terminal portion provided on a surface of an FPC substrate to an electrode terminal portion provided on a surface of an image display panel formed by bonding a first substrate and a second substrate,
The crimping head has a side surface and a bottom surface,
a holding portion for holding a tip end of the FPC board is provided on the side surface,
the pressure-bonding head pressure-bonds the electrode terminal portion of the FPC board to the electrode terminal portion of the image display panel with the bottom surface while holding the tip portion of the FPC board with the holding portion;
A pressure bonding device characterized by: The crimping head crimps and bonds the electrode terminal portion of the FPC board to the electrode terminal portion of the image display panel with the bottom surface while pressing the FPC board against a corner of a step portion formed between the outer periphery of the first substrate and the outer periphery of the second substrate. The crimping device according to claim 1, characterized in that the crimping head crimps and bonds the electrode terminal portion of the FPC board to the electrode terminal portion of the image display panel with the bottom surface. The crimping and bonding device according to claim 1 or 2, characterized in that the holding section holds the FPC board by vacuum suction.

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