JP2786980B2 - Manufacturing method of liquid crystal display - 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 for manufacturing a liquid crystal display. More specifically, a liquid crystal display panel and a circuit board that drives the liquid crystal display panel are TAB (Tape Automated Bonus).
ding).

The term "TAB" as used herein means that a large number of foil-like lead wires are held by a flexible film and connects one circuit terminal portion to another circuit terminal portion and has flexibility. Also includes those having a signal processing circuit such as an IC in the middle of the foil lead wire.

[0003]

2. Description of the Related Art A liquid crystal display device has a low power consumption and is easy to handle.
Widely used for A equipment. Taking advantage of the low power consumption and long life characteristics of the liquid crystal display device, the use of the liquid crystal display device for a large display board such as a guide display at a station or a street has begun to be studied.

In order to form a large screen with a liquid crystal display device, it is conceivable to form a large screen by arranging liquid crystal display devices having, for example, a liquid crystal display panel of about 10 cm square in a linear or matrix form. In the liquid crystal display device, for example, as shown in a perspective view of FIG. 2, electrode terminals are led out on both side surfaces of the liquid crystal display panel 11, and lead terminals of the TAB 12 are connected by an anisotropic conductive adhesive film. Circuit boards 13 and 14 on which circuits for driving the respective pixels are formed are connected to the other lead terminal of the TAB 12, and the circuit boards 13 and 14 are about 90
It is bent in the direction of ゜ and fixed to the case 19. The circuit boards 13 and 14 are bent in the right-angle direction in order to arrange the liquid crystal display devices as closely as possible. Therefore, the liquid crystal display panel and the driving circuit board are connected by a flexible TAB. As shown in FIG. 3, the TAB 12 has a very thin lead wire 15 held by a film 16, and the liquid crystal display panel 11 and the circuit boards 13 and 14 are normally bent in a vertical direction. In order to make the TAB 12 bend easily, the film
Are provided, and the lead wire 15 is exposed. This T
Since the AB 12 is provided with an IC 20 for performing signal processing, the number of leads 15 on the liquid crystal display panel 11 is large, but the number of leads 15 on the circuit board 13 is small.

In order to solder a lead wire to the end of the TAB 12, a connection slit 18 is formed without providing a film 16, and the lead wire 15 is exposed. The lead 15 is soldered to the lead terminal of the circuit board 13 at the connection slit 18.

[0006]

In the liquid crystal display device having such a structure, the TAB 12 has the weakest slit 17 where the lead wire 15 is exposed without forming a film, and is easily bent at that portion. On the other hand, the lead wire is very thin, having a thickness of about 35 μm and a width of about 100 μm. Therefore, when a force is applied to the TAB during alignment for connection between the lead terminal of the TAB 12 connected to the liquid crystal display panel and the lead terminals of the circuit boards 13 and 14, there is a problem that the lead wire is easily cut. .

[0007] In addition, a test is performed to determine whether or not the device operates normally after assembling the device.
When a test connector is inserted into or removed from a connector provided on a circuit board, a force is applied to a lead wire portion of the TAB, which causes a problem that the test connector is easily broken.

Further, there is a problem that, even during the manufacturing process, the handling is extremely difficult and the thin lead wires are easily damaged.

The present invention solves such a problem, and provides a method of manufacturing a liquid crystal display device that can manufacture, test, and ship a liquid crystal display device without bending the TAB and that does not inadvertently break lead wires. Things.

[0010]

According to the method of manufacturing a liquid crystal display device of the present invention, (a) one end of TAB is connected to each electrode terminal of a liquid crystal display panel having a liquid crystal material sandwiched between two transparent substrates;
(B) After arranging a circuit board and a liquid crystal display panel to which the TAB is connected on a liquid crystal display device tray provided with a liquid crystal display panel and a positioning guide for the circuit board, the other end of the TAB and the And (c) conducting an electrical test while the liquid crystal display panel is provided in the tray.

[0011]

According to the method of manufacturing a liquid crystal display device of the present invention, both the liquid crystal display panel and the circuit board are positioned by the tray, and after slight positional adjustment, the terminal of the TAB lead wire and the terminal of the circuit board can be soldered. Therefore, soldering can be performed without applying unnecessary force to the TAB. In addition, the performance test can be performed by simply illuminating the backlight from the back side while holding the tray using the opening provided on the bottom of the tray and bringing the test probe into contact with the input terminal of the circuit board. After bonding the LCD panel and the circuit board, it is not necessary to lift the LCD panel one by one, and it is not necessary to connect a test connector. Does not break.

[0012]

Next, a method of manufacturing a liquid crystal display device according to the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view illustrating a liquid crystal display device according to an embodiment of the present invention, in which a circuit board and a liquid crystal display panel are incorporated in a liquid crystal display device tray (hereinafter, referred to as a tray).

First, the liquid crystal display panel 11 is formed by a usual method. That is, an electrode film and an orientation film such as an ITO film and a tin oxide film are provided on a transparent substrate such as two glass substrates and a plastic plate, and a sealing agent layer is printed, and the substrates are bonded together with spacers interposed therebetween. Is formed by filling a liquid crystal material. The electrode films provided on the transparent substrate are led out to both ends of the transparent substrate as electrode terminals, and are connected to external leads.

One end of a TAB lead wire is connected to an electrode terminal of the liquid crystal display panel. TAB is formed by holding a large number of foil-like lead wires with a flexible film, and one end of each is formed with each electrode terminal of an electrode film of a liquid crystal display panel, and the other end is formed with a drive circuit for driving the liquid crystal display panel. Each of the terminals of the wiring pattern of the circuit board (printed board) is electrically connected to bend on the way. In order to connect the liquid crystal display panel 11 and the TAB 12, for example, the electrode terminals of the liquid crystal display panel 11 and the lead wire terminals of the TAB 12 are aligned and bonded with an anisotropic conductive adhesive film (ACF) therebetween. Here, the anisotropic conductive adhesive film is an adhesive film in which conductive particles obtained by applying gold plating to a resin ball having a particle size of about 5 μm are mixed with an epoxy adhesive. Extruded into the part, even those with irregularities are evenly adhered, the convex part has conductivity by pressing the conductive particles, and the concave part has an adhesive effect but does not contact between the conductive particles, It does not have conductivity in the lateral direction.

As a specific example of bonding by interposing an anisotropic conductive adhesive film, for example, the liquid crystal display panel 11 and the TA
B12, pressure 150 ~ 170 ℃, pressure 15 ~ 20k
Adhesion is performed by heating and pressing at about gf / cm ^{2 for} about 30 to 40 seconds.

Next, the terminal portions of the circuit boards 13 and 14 and the TAB 12 having one end connected to the electrode terminals of the liquid crystal display panel 11 are connected.
And the other end of the lead wire. This circuit board 13,
To connect 14 to the other end of the TAB12 lead,
First, the circuit boards 13 and 14 are positioned and arranged on the tray 1 on which the positioning guides 3 and 4 are provided. Then TAB
The liquid crystal display panel 11 to which one end of the liquid crystal display panel 12 is bonded is moved along the first guide portion 2 for the liquid crystal display panel of the tray 1.
And the other end of the TAB12 lead wire and the circuit board 1
The other ends of the lead wires of the TAB 12 and the terminal portions of the circuit boards 13 and 14 are adhered to each other by soldering such as by hand soldering or pressing with a heating tool.

The tray 1 is a shallow plate-like container made of, for example, a polycarbonate resin formed by molding or the like.
A first guide portion 2 for positioning the liquid crystal display panel 11,
A second guide section 3 for positioning the circuit board 13 and a third guide section 4 for positioning the circuit board 14 are provided. The liquid crystal display panel 11 and the circuit are arranged so that a square is engaged at this position. When the substrates 13 and 14 are placed on the tray 1, the connection slits 18 of the TAB 12 previously adhered to the liquid crystal display panel 11 with only slight alignment.
However, it is configured to come into contact with the connection portion 19 of the circuit board 13. Therefore, the liquid crystal display panel 11 and the circuit board 13,
In the step of connecting the TABs 12 and 14, the work can be performed without directly touching the TAB 12, and the TAB 12 is not inadvertently bent. A panel opening 5 for exposing the back surface of the liquid crystal display panel 11 is provided on the bottom surface of the tray 1.
And the input terminals of the circuit board on the back of the circuit boards 13 and 14
Terminal openings 6a, 6 for exposing 20a, 20b, 20c
b and 6c are provided.

Next, while the liquid crystal display device having the circuit board connected to the other end of the TAB lead wire is disposed in the tray, an electrical test such as lighting confirmation is performed. In this test, a power supply and an input signal are connected to the input terminals of the circuit board, and a test pattern is drawn.
The quality of the display characteristics is directly inspected. As a test pattern, lighting all dots,
A pattern is used in which every other dot is alternately lit or a specific picture is drawn.

As described above, the tray 1 is provided with the panel opening 5 and the terminal openings 6a, 6b, 6c at the center as described above. For this reason, a backlight is provided on the lower surface of the tray 1 and the liquid crystal display device is put into the tray 1 by directly contacting the input terminal lead wires exposed at the terminal openings 6a, 6b, 6c with a probe or the like. The test was carried out as it was.

The circuit board is provided with sockets 21a, 21b, and 21c for connection to external leads. By utilizing the fact that each lead of the socket is exposed on the back side of the circuit board, A performance test is performed only by bringing the test probe into contact with the device, and the attachment / detachment to / from the socket is unnecessary. As a result, the performance test can be performed without directly touching the TAB 12, so that no unnecessary force is applied to the TAB 12 or the TAB 12 is not carelessly bent. Finally, as shown in Fig. 2, the case is folded at the TAB
If it is fixed to 19, TAB will be used for subsequent shipment
Does not take power. Also, when the product is shipped in the tray 1 and is fixed freely by the user, it can be moved in the tray and no unnecessary force is applied to the TAB. Therefore, external force to the TAB can be minimized.

The liquid crystal display device of this embodiment is, for example, 24 dots × 24 dots, and the size of the liquid crystal display panel is about 90 mm × 24 dots.
90 mm, the size of one TAB 12 is about 30 mm x 20 mm, the size of the circuit boards 13 and 14 is about 40 mm x 90 mm, and the outer shape of the tray 1 is about 240 mm x 135 mm. The size can be determined as appropriate, and is not limited to this example.

In the above-described embodiment, an example in which circuit boards are provided on both sides of the liquid crystal display panel has been described.

[0023]

According to the present invention, after the liquid crystal display panel and the circuit board are connected, the assembly of the liquid crystal display device is continued while being placed in the tray, and the test is carried out while being held in the tray. Unnecessary bending stress is not applied to the lead wire, the lead wire is not broken, the reliability is improved, and the liquid crystal display device can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an assembly for explaining one embodiment of a method for manufacturing a liquid crystal display device of the present invention.

FIG. 2 is a perspective view of an example of a state in which the liquid crystal display device is attached to a case.

FIG. 3 is an enlarged explanatory view of a TAB portion of the liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tray 2 1st guide part 3 2nd guide part 4 3rd guide part 11 Liquid crystal display panel 12 TAB 13,14 Circuit board

Claims (1)

(57) [Claims] 1. One end of a TAB is connected to each electrode terminal of a liquid crystal display panel in which a liquid crystal material is sandwiched between two transparent substrates, and (b) positioning guide portions for the liquid crystal display panel and a circuit board are provided. After the circuit board and the liquid crystal display panel to which the TAB is connected are provided on the provided liquid crystal display device tray, the other end of the TAB is connected to the terminal portion of the circuit board, and (c) the tray A method for manufacturing a liquid crystal display device, wherein an electrical test is performed while a liquid crystal display panel is provided inside the liquid crystal display device.