JPH0961118A - Alignment optical system of driver chip for liquid crystal cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clearly pick up the image of the alignment mark of both of TFT substrate of a liquid crystal cell and a driver chip connected to it. SOLUTION: An alignment optical system is constituted of a ring light projection part 61 for applying a flux of ring beams to marks MC1 and MC2 for alignment in oblique direction, a vertical light projection part 62 for vertically applying a flux of parallel light to marks MT1 and MT2 of the TFT substrate 11 in the state approaching both marks MC1 and MC2 , light shutters 612 and 622 for alternately switching the ring light projection part 61 and the vertical light protection part 62, and a common TV camera 63 for the marks MC1 and MC2 and MT1 and MT2 . The alignment can be accurately performed by the constitution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment optical system for aligning alignment marks provided on both a liquid crystal cell and a driver chip with each other.

[0002]

2. Description of the Related Art A color liquid crystal panel, which is widely used in various fields, is mainly composed of a liquid crystal cell and a color filter, and is manufactured by complicated and precise multi-step processing and assembling steps. FIG. 3 shows an appearance of an example of the liquid crystal cell 1. The liquid crystal cell 1 has a TFT substrate 11 in which a large number of pixel electrodes composed of TFT elements are arranged in a matrix, and a glass plate 12 forming an appropriate gap with respect to the TFT substrate 11, and a liquid crystal material is enclosed in the gap. Has been done. A plurality of input lead wire groups 111 for each TFT element are arranged on the surfaces of two opposite sides of the TFT substrate 11, and each input lead wire group 111 is arranged.
Is connected to an external circuit by an appropriate connection method, for example, a TAB (Tape Automated Bonding) method. In the TAB method, a TAB2 in which the required pattern wirings 22 and 23 are printed on a transparent tape 21 such as polyimide
The IC chip 3 is mounted in the vicinity of its center, and its output lead wire group 31 and input lead wire group 32 are patterned.
22 and 23 are connected respectively. Positioning marks M ₁ and M ₂ are printed on both sides of the pattern wiring 22 at the same time. Correspondingly, the respective input lead wire groups 11 of the TFT substrate 11 are printed.
Marks M _T1 and M _T2 are also provided on both sides of 1, and the corresponding ones of the marks are aligned with each other by the aligning device 5 (FIG. 5) described later, and then TAB2 and the input lead wire group 11
Insert ACF (anisotropic conductive sheet) between 1 and TAB
When 2 is pressed, both are connected.

In the above, a plurality of lead wire groups 111
Are arranged on two opposite sides of the TFT substrate 11, but if these are put together on one side, the so-called frame portion around the TFT substrate 11 is reduced accordingly, so the size of the image surface of the liquid crystal panel. Is enlarged by that amount, and it is advantageous for taking a plurality of sheets when manufacturing the TFT substrate 11. On the other hand, TA
B2 has a limit in the pitch interval of the wiring and cannot support the higher definition of the liquid crystal panel which is progressing more and more.
Instead of No. 2, a method has been developed in which an IC chip with a narrow pitch between lead wires is used and is directly connected to each lead wire group 111. In this case, the IC chip is the TFT substrate
This is called the COG (chip on glass) method because it makes contact with the glass surface of 11. This IC chip is called the COG.

A connection method according to the COG method will be described with reference to FIG. In (a), the TFT substrate 11 is provided with a plurality of sets of input lead wire groups 111 on one side of one side thereof.
COG4 is connected to each of these, and each COG4 is connected to an external circuit by TAB2. (b)
Indicates a concrete connection method, and as shown in the plan view, CO
At the two corners of G4, the marks M _T1 , M of the TFT substrate 11 are
Marks M _C1 and M _C2 corresponding to _T2 are provided. COG4
Is set as a fixed position, the TFT substrate 11 placed therebelow is moved to align the marks of both, and then the AC is placed between the two.
When F is inserted and COG4 is pressed, output lead wire group 41 of COG4 is connected to input lead wire group 111 of TFT substrate 11. The input lead wire group 42 of each COG 4 is an IC
The chipless TAB2 is connected and connected to an external circuit.

FIG. 5 shows a schematic configuration of the alignment device 5 applied to the TAB connection system of FIG. 3, and its operation will be described with this as a prior art. In the alignment device 5,
TAB2 is chucked on the robot hand 51, and the TFT substrate
11 is placed on the XYθ stage 52, and the marks (M ₁ , M ₂ ) and the marks (M _T1 , M _T2 ) for alignment are stopped within the visual field of the alignment optical system 53. The illumination light from the lamp light source 531 passes through the half mirror 532, is collimated by the objective lens 533, and is radiated perpendicularly to each mark of both. The irradiated marks are imaged by the TV camera 534, and the respective image signals are input to the control signal generating circuit 54, the coordinate position of each mark is detected, and the XY control signal and the θ control signal are generated. Both control signals are XYθ stage
Input to 52, the mark M _{T1 of} the mounted TFT substrate 11,
Move M _T2 in X or Y, or rotate by θ to move TAB
The two marks M ₁ and M ₂ are aligned with each other so as to coincide with each other.

[0006]

In principle, it is possible to apply the above-mentioned alignment device 5 to the COG connection system shown in FIG. However, the alignment optical system 53
Has its drawbacks. That is, in the COG 4, as shown in FIG. 6, the pattern wiring 43 is densely formed over the entire area, and since it is close to the marks M _C1 and M _C2 , the illumination light is irradiated vertically to these. And both are T
The difficulty is that the V camera 534 clearly captures the image and it is difficult to distinguish the images. To solve these difficulties, CO
By improving the illumination method for G4, the pattern wiring 43 is unclear on the TV camera 534, and the alignment marks M _C1 and M
_C2 needs to be clearly imaged. The present invention has been made in view of the above, and provides an alignment optical system suitable for a COG connection method, which makes the pattern wiring of the COG 4 unclear and clearly captures each mark of the TFT substrate 11 and the COG (driver chip) 4. The purpose is to provide.

[0007]

SUMMARY OF THE INVENTION The present invention is a positioning optical system for achieving the above object, which is a ring projection for irradiating the marks M _C1 and M _{C2 of} a driver chip with a ring light beam in an oblique direction. The mark M of one set of input lead wire group of the TFT substrate in a state of being close to the optical part and both marks M _C1 and M _C2
A vertical light projecting unit for vertically irradiating a parallel light beam with respect to _T1 and M _T2 , a switching means for alternately switching between a ring light projecting unit and a vertical light projecting unit, and a mark M to which each light beam is irradiated.
_C1 and M _C2 and a common TV camera for the marks M _T1 and M _T2 .

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the above-described alignment optical system, for example, the ring light projecting portion is first operated by switching means (in the embodiments described later, insertion and removal of the optical shutters 612 and 622) to operate the driver chip. Mark M _C1 , M
_A ring light flux is radiated obliquely to _C2 , and this is sent to the TV.
Take an image with a camera. It has been confirmed by an experiment that the pattern wiring of the driver chip is unclear and the marks M _C1 and M _C2 are clearly imaged by the TV camera by irradiating the ring light flux obliquely in this way. Thus, the two can be easily distinguished and the coordinate values of the marks M _C1 and M _C2 can be accurately obtained. Then, the vertical light projecting unit is operated by the switching means to irradiate the parallel light flux vertically to the marks M _T1 and M _{T2 of the} set of input lead wires on the TFT substrate. This irradiation method is the same as the conventional one, and the marks M _T1 and M _T2 are clearly imaged by the TV camera, and the coordinate values thereof are accurately obtained. Positioning is accurately performed by the coordinate values obtained as described above.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the construction of an alignment optical system 6 in an embodiment of the present invention. The alignment optical system 6 is provided in place of the optical system 53 of the alignment device 5 in FIG. 5, and other parts, that is, the robot hand 51 and the XYθ stage 5
2. The control signal generating circuit 54 and the like are used as they are. The alignment optical system 6 includes a ring light projecting portion 61, a vertical light projecting portion 62,
And a TV camera 63. However, the TV camera 63 may be the conventional TV camera 534. Ring projector 61
Is a lamp light source 611 and an optical shutter 612 of the switching means.
, And a ring projector 613, the vertical projector 62
Includes a lamp light source 621, an optical shutter 622, and a projection lens 62.
3 and half mirror 624.

FIG. 2 is an explanatory view of the ring projector 613, (a)
Indicates a structure, and the ring projector 613 circulates a plurality of optical fibers (OPF) in a circle with an appropriate diameter, arranges the tips of the OPFs at a constant angular interval, and slants them toward the inside. It is directed in a radial direction, the rear end is collectively used as a light input end, and this is molded, and various sizes are commercially available. In (b), when a light beam from the lamp light source 611 is incident on the light input end, a ring-shaped light beam is emitted from the tips of all OPFs,
Irradiate the entire circumference of the COG 4 in an oblique direction.

The alignment method by the alignment optical system 6 will be described below. The COG 4 is chucked by the robot hand 51 and stopped at a predetermined position within the field of view of the TV camera 63 by handling. On the other hand, the TFT substrate 11 is XYθ
It is placed on the stage 52 and moved appropriately to save it out of the field of view, and the optical shutter 622 is inserted to stop the operation of the vertical light projecting unit 62. Then, when the optical shutter 612 is pulled out, the ring light projecting unit 61 operates, the light flux of the lamp light source 611 enters the ring light projector 613, and the entire circumference of the COG 4 is illuminated obliquely in the ring direction, and the marks (M _C1 , M A clear image of _C2 ) is captured by the TV camera 63, and the pattern wiring 43 is captured indistinctly.

Next, by moving the TFT substrate 11 which is being evacuated,
The mark (M _T1 , M _T2 ) is the COG4 mark (M _C1 ,
M _C2 ), and then the optical shutter 612 is inserted to stop the operation of the ring light projecting unit 61. Then, the optical shutter
Pull out 622 to project the luminous flux of the lamp light source 621
3 incident light to make it parallel, and through half mirror 624, TFT
When the substrate 11 is vertically irradiated, the mark (M _T1 , M _T2 ) is clearly captured by the TV camera 63. As described above, the image signal of the TV camera 63 captured clearly is input to the control signal creating circuit 54 as in the conventional case, the coordinate value of each mark is detected, and the XY control signal and the θ control signal are created. When the XYθ stage is moved or rotated by the control signal so that the marks of both are aligned with each other, the input lead wire group 111 of the TFT substrate 11 and the output lead wire group 43 of the COG 4 are aligned, and between them. The inserted ACF and the pressure are connected to each other.

[0013]

As described above, in the alignment optical system of the present invention, the ring illumination light is obliquely irradiated by the ring light projecting portion provided for the driver chip to form the pattern wiring of the driver chip. Indistinctly, the alignment mark is clearly imaged by a TV camera, and parallel light is vertically emitted to the TFT substrate by a vertical light projecting unit.
The alignment mark can be accurately imaged with a TV camera to accurately align the marks with each other, and the effect of contributing to the alignment technique in the COG connection method is great.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an alignment optical system in an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a ring projector, (a) is a structural diagram, and (b) is an explanatory diagram of an operation.

FIG. 3 is an external view of a TAB connection type liquid crystal cell.

4A and 4B are explanatory views of a liquid crystal cell of a COG connection system, where FIG. 4A is a structural diagram and FIG. 4B is an explanatory diagram of a connection method.

FIG. 5 is a configuration diagram of a positioning device which is applied to a TAB connection system and is a prior art of the present invention.

FIG. 6 is an array diagram of pattern wiring and alignment marks of a driver chip (COG).

[Explanation of symbols]

1 ... Liquid crystal cell, 11 ... TFT substrate, 111 ... Input lead wire group, 12 ... Glass plate, 2 ... TAB, 21 ... Transparent tape, 22, 2
3 ... Pattern wiring, 3 ... IC chip, 31 ... Output lead wire group, 32 ... Input lead wire group, 4 ... Driver chip (CO
G), 41 ... Output lead wire group, 42 ... Input lead wire group, 43 ...
Pattern wiring, 5 ... Positioning device, 51 ... Robot hand,
52 ... XYθ stage, 53 ... Prior art alignment optical system,
531 ... Lamp light source, 532 ... Half mirror, 533 ... Objective lens, 534 ... TV camera, 54 ... Control signal generation circuit, 6
... Positioning optical system of the present invention, 61 ... Ring projection unit, 611
... lamp light source, 612 ... optical shutter, 613 ... ring projector, 62 ... vertical light projecting portion, 621 ... lamp light source 622 ... light shutters, 623 ... projection lens, 624 ... half mirror, 63 ... TV camera M _1, M ₂ ... TAB2 alignment marks, M _T1 , M _T2 ...
Positioning marks on the TFT substrate 11, M _C1 , M _C2 ... COG
Positioning mark of 4.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01L 21/336

Claims (1)

[Claims] 1. A plurality of sets of input lead wire groups formed on one side of a TFT substrate which is a constituent element of a liquid crystal cell, and alignment marks M _T1 and M _T2 provided on both sides of each set, and a set of the alignment marks M _T1 and M _T2. In the alignment with the alignment marks M _C1 and M _C2 of the driver chip having the output lead line group connected to the input lead line group, a ring is slanted with respect to the marks M _C1 and M _{C2 of the} driver chip. A ring light projection unit that irradiates a light flux,
With respect to the marks M _T1 and M _{T2 of the} set of input lead wires of the TFT substrate in the state of being close to both the marks M _C1 and M _C2 ,
A vertical light projecting unit for vertically irradiating a parallel light beam, a switching means for alternately switching between the ring light projecting unit and the vertical light projecting unit, and marks M _C1 , M _C2 and a mark M _T1 respectively irradiated with the light beam. An alignment optical system for a driver chip for a liquid crystal cell, which is configured by a TV camera common to M _T2 .