JP2003229455A - Electro-optical panel, electro-optical device, electronic apparatus, and method of manufacturing electro-optical panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate a space and a process for special use for forming an alignment mark, to increase the space usage efficiency of an electro-optical panel, and to simplify manufacturing processes of the electro-optical panel. <P>SOLUTION: In the electro-optical panel such as a liquid crystal display panel (1), interconnections (12) for establishing the continuity with an object to be mounted such as an IC for driving (10) are formed. For alignment when mounting the IC for driving on the electro-optical panel, an alignment mark (27) on the IC side which is formed in the IC for driving and alignment marks (17 and 24) on the substrate side which are formed in the electro-optical panel are used. The alignment marks on the substrate side are formed inside the interconnections formed in the electro-optical panel at the same time with the interconnections. Consequently, there is no necessity of a space for special use for the alignment marks on the electro-optical panel side, and a process for forming only the alignment marks is not necessary, either. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning method for mounting an IC on a panel in an electro-optical device such as a liquid crystal display device.

[0002]

2. Description of the Related Art In a liquid crystal display device, a liquid crystal driving IC is mounted on a liquid crystal display panel in which liquid crystal is sealed between two transparent substrates facing each other. For example, COG (Chip On Glas
In the s) method, the driving IC is directly attached to one of the two transparent substrates via an ACF (Anisotropic Conductive Film) or the like. In addition, FPC (Flex
When a flexible printed circuit board is used, the driving IC is attached to the FPC board and then the FPC board is attached to the liquid crystal display panel.

As described above, when the driving IC is attached to the liquid crystal display panel substrate or the FPC substrate, it is necessary to relatively align the both. This alignment is performed by forming marks, which are generally called alignment marks, on both the driving IC and the liquid crystal display panel substrate so that the corresponding alignment marks may overlap, or the corresponding alignment marks may be predetermined. This is done by arranging the driving IC and the liquid crystal display panel substrate so as to come to the relative position.

[0004]

However, the above method requires a step for forming an alignment mark on the liquid crystal display panel substrate side during the manufacturing process of the liquid crystal display device, which increases the number of steps. There is.

There is also a problem that a dedicated space for forming the alignment mark is required on the liquid crystal display panel and the utilization efficiency of the space is lowered.

The present invention has been made in view of the above points, eliminates the need for a dedicated space and process for forming alignment marks, improves space utilization efficiency of the electro-optical panel, and simplifies the manufacturing process. The task is to do.

[0007]

According to one aspect of the present invention, an electro-optical panel is provided with a wiring for electrical connection with an object to be mounted and an alignment mark provided in the wiring.

Wirings are formed on an electro-optical panel such as a liquid crystal display panel for electrical connection with an object to be mounted such as a driving IC. The IC-side alignment mark formed on the driving IC and the substrate-side alignment mark formed on the electro-optical panel are used for alignment when mounting the driving IC on the electro-optical panel. Here, the substrate-side alignment mark is formed inside the wiring formed on the electro-optical panel. Therefore, a space dedicated to the alignment mark on the substrate side becomes unnecessary.

In one aspect of the electro-optical panel described above, the alignment mark can be formed of a metal material forming the wiring. Further, the metal material may be APC used as a reflective film, in which case the wiring is APC and ITO formed on the APC.
Can be included.

In one aspect of the electro-optical panel described above, the alignment mark may include a transparent portion in which the layer of the metal material is not formed. In that case, if the driving IC and the electro-optical panel are arranged such that the IC-side alignment mark is located in the transparent portion, the alignment can be easily performed by a CCD camera or the like. Further, even after the alignment, it is possible to easily confirm whether the alignment is correctly performed by visually or visually confirming that the IC side alignment mark exists in the transparent portion.

An electro-optical device can be constructed by using the electro-optical panel described above, and an electronic device having the electro-optical device as a display section can be constructed.

According to another aspect of the present invention, a method of manufacturing an electro-optical panel has a step of simultaneously forming a wiring and an alignment mark for electrical connection with a mounting object on a substrate.

Wirings are formed on an electro-optical panel such as a liquid crystal display panel for conduction with a mounting object such as a driving IC. The IC-side alignment mark formed on the driving IC and the substrate-side alignment mark formed on the electro-optical panel are used for alignment when mounting the driving IC on the electro-optical panel. According to the above method, since the alignment mark is formed on the electro-optical panel at the same time as the wiring is formed, the dedicated step of forming the alignment mark can be omitted and the manufacturing process of the electro-optical panel can be simplified.

In one aspect of the above manufacturing method, the wiring and the alignment mark can be formed on the substrate as a film of the same metal material. Thereby, the wiring and the alignment mark can be efficiently formed.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 shows a liquid crystal display panel according to a first embodiment of the present invention. FIG. 1A is a plan view of the liquid crystal display panel 1, and FIG.
It is sectional drawing in AA 'of the liquid crystal display panel 1 shown to (a). As shown in the figure, in the liquid crystal display panel 1, two transparent substrates 2 and 3 are arranged to face each other with a sealing material 5 interposed therebetween (hereinafter, also referred to as “lower substrate 2” and “upper substrate 3”), The liquid crystal 7 is enclosed in the cell gap formed by them.

Incidentally, drive electrodes for driving the pixels of the liquid crystal display panel, an alignment film, a color filter and the like are formed on the transparent substrates 2 and 3 as required.
In the figure, the illustration is omitted for convenience.

As shown in FIG. 1A, the lower substrate 2 has a region 4 wider than the upper substrate 3 (hereinafter referred to as "overhang region"). On the overhang area 4, the driving IC 1
0 is attached using ACF, for example. Further, on the lower substrate 2, a plurality of wirings 12 are formed in the projecting region 4, and terminals 11 for inputting a control signal from the outside are formed at the end of the projecting region 4.
The wiring 12 is a plurality of input-side wirings 12 for supplying a control signal supplied from the outside through the terminal 11 to the driving IC 10.
a and an output side wiring 12b for supplying a drive signal from the drive IC 10 to a drive electrode (not shown) in the display area 6 of the liquid crystal display panel 1.

In one embodiment of the present invention, the driving IC 10 shown in FIG.
On the method of positioning on. 2A is an enlarged view of the ellipse 20 in FIG. 1A of the liquid crystal display panel 1 as viewed from the right side of FIG. 1, and for convenience of description, the driving IC 10 arranged thereon is shown. The position is shown at the same time. In the driving IC 10, one corner included in the ellipse 20 is shown in FIG.
That is, a plurality of wirings 12a are formed on the projecting region 4 at the corresponding positions. The wiring 12a has a tip portion 16 having a large area at its tip portion, and the driving IC 10 is attached to the overhang area 4 so that the tip portion 16 comes into contact with a bump formed on the lower surface of the driving IC 10. Be worn.

APC (silver-palladium-copper alloy: Ag-Pd-Cu) is formed inside the wiring 12a. Since APC has a higher reflectance than aluminum, it is used as a reflective film of a transflective liquid crystal device as an alternative to conventional aluminum. APC has a weak water resistance during the manufacturing process, which may cause electromigration and electrolytic corrosion.
ITO is laminated on the upper layer and used.

Here, in the first embodiment, the wiring 1
The feature is that an alignment mark 17 (hereinafter, also referred to as “substrate-side alignment mark”) is formed by APC in the tip portion 16 of 2a. Note that FIG.
Although the example of (a) shows an example in which two alignment marks 17 are formed in one tip portion 16, only one alignment mark 17 may be formed in one tip portion 16. .

Further, in this example, the alignment mark 17 is formed only on the leftmost wiring 12a in FIG. 2 (a). In one common method, the driving IC 10
A pair of IC-side alignment marks are formed in the vicinity of both ends in the length direction, and a corresponding pair of substrate-side alignment marks are formed at positions separated in the length direction of the overhang region of the liquid crystal display panel. A driving IC so that a corresponding set of IC-side alignment marks and substrate-side alignment marks have a predetermined relative positional relationship.
Is positioned. Therefore, in this example, the driving IC
The substrate-side alignment mark 17 is formed on the outermost wiring 12a in the length direction. However, the substrate-side alignment mark 17 is not limited to this, and the driving IC 10
It is possible to form the wiring 12 at any position among the plurality of wirings 12 to be connected to.

FIG. 2B shows B- in FIG. 2A.
It is sectional drawing along B '. Regarding the wiring 12a (the leftmost wiring in FIG. 2A) on which the substrate-side alignment mark 17 is formed, firstly ITO, SiO ₂ , Cr is formed on the lower substrate 2 of the liquid crystal display panel 1 as shown in the figure. Alternatively, the conductive film 18 of Ta or the like is formed, the APC 15 is formed thereon, and the ITO conductive film 19 is further formed thereon. On the other hand, for the wiring 12a (two wirings on the right side of FIG. 2A) in which the substrate-side alignment mark is not formed, the conductive film 18 of ITO, SiO ₂ , Cr, or Ta is formed on the lower substrate 2, and A conductive film 19 of ITO is formed on the top. The conductive films 18 and 19 have conductivity and also have a function as a protective film for APC.

FIG. 2C shows C- in FIG. 2A.
It is sectional drawing along C '. At the position C-C ', all the wirings 12a have the same configuration. That is, first, ITO, SiO ₂ , Cr or T is formed on the lower substrate 2.
A conductive film 18 such as a is formed, an APC 15 is formed thereon, and an ITO conductive film 19 is further formed thereon.

In the structure shown in FIGS. 2 (a) to 2 (c),
The lower substrate 2 is a transparent substrate such as glass or plastic, and the conductive film such as ITO is also transparent. Therefore, if an image is taken from below the lower substrate with a CCD camera or the like, the APC 1
Since the portion 5 is opaque, its shape can be detected. Therefore, it is possible to detect the substrate side alignment mark 17 and perform positioning with the IC side alignment mark.

As a positioning method, specifically, first, the liquid crystal display panel 1 and the driving IC 10 are placed on the same coordinate system, and the coordinates of the IC side alignment mark and the substrate side alignment mark are picked up by a CCD camera or the like. And the coordinates of. Then, based on the detected coordinates, the driving IC is moved by a transfer robot or the like so that the IC-side alignment mark and the substrate-side alignment mark have a predetermined positional relationship, and an appropriate position on the overhang area of the liquid crystal display panel. Place in position. ACF or the like is attached in advance to the projecting area of the liquid crystal display panel, and the driving IC is attached to the liquid crystal display panel by thermocompression bonding, and the mounting work is completed.

As described above, according to the present invention, when the wiring 12 is formed on the lower substrate 2, the substrate side alignment mark 17 can be simultaneously formed by APC. Therefore, a dedicated process for forming only the alignment mark on the substrate of the liquid crystal display panel is unnecessary, and the manufacturing process of the liquid crystal display panel substrate can be simplified.

Further, since the substrate side alignment mark of the liquid crystal display panel can be formed in the wiring, it is not necessary to secure a dedicated space for forming the alignment mark in the projecting region of the liquid crystal display panel. Therefore, it is possible to enlarge the display area (widen the frame) by increasing the space that can be used for routing the wiring in the overhang area or by efficiently utilizing the space in the overhang area.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is similar to the first embodiment in that the substrate side alignment mark is formed in the wiring on the lower substrate 2 of the liquid crystal display panel, but the shape of the substrate side alignment mark is different. In FIG. 3A, the lower substrate 2 of the liquid crystal display panel 2 on which the substrate-side alignment marks 24 of this embodiment are formed.
The wiring part of is shown. Note that FIG. 3A is an enlarged view of a portion of the ellipse 20 shown in FIG. 1A, as in the case of the first embodiment, and shows a part of the driving IC 10 together for convenience of description. There is.

As shown in FIG. 3A, in this embodiment, the substrate side alignment mark 24 has two circular transparent portions 25. Substrate side alignment mark 2
4 is formed by APC as in the first embodiment. On the other hand, the driving IC 10 has a substrate-side alignment mark 2
An IC side alignment mark 27 is formed at a position corresponding to the transparent portion 25 of No. 4.

In the first embodiment, the driving IC 10 and the lower substrate 2 are positioned so that the substrate-side alignment mark 17 and the IC-side alignment mark (not shown) have a predetermined positional relationship. On the other hand, in the present embodiment,
Positioning is performed using the substrate side alignment mark 24 and the IC side alignment mark 27. That is, the driving IC 10 and the lower substrate 2 of the liquid crystal display panel 1 are relatively positioned so that the IC side alignment mark 27 of the driving IC 10 is located inside the transparent portion 25 of the substrate side alignment mark 24. Done.

FIG. 3 (b) is a sectional view taken along the line DD 'in FIG. 3 (a). As shown in the figure, the wiring 12a (the leftmost wiring in FIG. 3A) on which the substrate-side alignment mark 24 is formed is first formed on the lower substrate 2 with ITO or Si.
A conductive film 18 of O ₂ , Cr, Ta or the like is formed, an APC 15 is formed thereon, and an ITO conductive film 19 is further formed thereon. Substrate side alignment mark 24
The transparent portion 25 of is formed of ITO. On the other hand, the wiring 12a in which the substrate side alignment mark is not formed (see FIG.
Regarding (2 wirings on the right side of (a)), I on the lower substrate 2
A conductive layer 18 made of TO, SiO2, Cr, or Ta is formed, an APC 15 is formed thereon, and an ITO conductive layer 19 is further formed thereon.

Regarding the wirings on which the substrate-side alignment marks 24 are not formed, instead of the two wirings on the right side of FIGS. 3A to 3C, the two wirings on the right side of FIGS. 2A to 2C are used. Wiring may be used.

[Modification] In the above example, the substrate side alignment mark is formed in the outermost wiring of the plurality of wirings 12a, but this wiring 12a may be a so-called dummy wiring. . The dummy wiring is a wiring that is formed to stably attach the driving IC to the liquid crystal display panel substrate and does not actually input / output a signal. Generally, such dummy wirings are often formed near both ends in the length direction of the driving IC, and the above-mentioned substrate-side alignment mark may be formed in such dummy wirings. .

The pair of substrate-side alignment marks are formed at positions corresponding to the vicinity of both ends of one side of the rectangular drive IC, and are also formed near corners on the diagonal of the rectangular drive IC. You can also As a result, the shift angle between the side in the length direction of the driving IC and the corresponding side of the liquid crystal display panel substrate is reduced, and the length direction of the driving IC is made as parallel as possible to the edge of the liquid crystal display panel substrate. It is easy to place it in.

The substrate side alignment mark of the present invention may be basically formed on either the input side wiring 12a or the output side wiring 12b. However, depending on the liquid crystal display panel, the input side wiring 12a may have a larger area than the output side wiring 12b. In such a case, it is possible to form the alignment mark itself larger by forming the substrate side alignment mark in the input side wiring having a large area, and it is possible to improve the accuracy of position detection by the CCD camera.

Further, although the above example shows the case where the APC is used in the wiring, a metal material other than the APC can be used as the reflection film or the like. Although the substrate-side alignment mark formed in the wiring is circular in the above example, it can be formed in various other shapes such as square, triangle, cross, and Y-shape.

[Manufacturing Method of Liquid Crystal Display Device] Manufacturing Method of Liquid Crystal Display Device] Next, a manufacturing method of a liquid crystal display device according to one specific example to which the present invention is applied will be described with reference to FIG.
This will be described with reference to the process chart shown in FIG.

First, a large-sized substrate material having a plurality of sizes of the lower substrate 2 shown in FIG. 1 is formed of glass, plastic, or the like, and in step A1, electrodes and wirings are formed on the large-sized substrate material. To do. Specifically, ITO
By using a well-known pattern forming method using, for example, a photolithography method, electrodes (not shown), wirings 12 and terminals 11 having a predetermined pattern are formed on the surface of the large-sized substrate material. At this time, simultaneously with the formation of the wiring 12, the substrate-side alignment mark according to the first embodiment or the second embodiment described above is formed on the substrate (step A1).

Next, an insulating layer is formed on the surface of the large-sized substrate material by offset printing, for example, using silicon oxide or titanium oxide as a material (step A2). Then, an alignment film is formed thereon by, for example, offset printing using a polyimide resin as a material (step A3), and a rubbing treatment is performed to impart orientation to the alignment film (step A4). Further, the sealing material 5 is formed in a frame shape by screen printing using epoxy resin as a material (step A5), and spacers are further dispersed (step A6).

On the other hand, a large-sized substrate material having a plurality of sizes of the upper substrate 3 shown in FIG. 1 is formed of glass, plastic, or the like, and in step B1, electrodes are formed on the large-sized substrate material. Specifically, an electrode having a predetermined pattern is formed on the surface of a large-sized substrate material by a well-known pattern forming method using ITO as a material, for example, a photolithography method.

Next, an insulating layer is formed on the surface of the large-sized substrate material by offset printing using, for example, silicon oxide or titanium oxide as a material (step B2). Then, an alignment film 9b is formed thereon by offset printing using a polyimide resin as a material (step B3), and a rubbing process is performed to impart orientation to the alignment film (step B3).

As described above, after two large-sized substrates corresponding to a plurality of liquid crystal display panels shown in FIG. 1 are manufactured, these large-sized substrates are superposed on each other with the sealing material 5 sandwiched therebetween in step C1. Both substrates are attached to each other by further pressure bonding, that is, by applying pressure under heating. By this bonding, a bonded substrate having a size including a plurality of liquid crystal display panel structures shown in FIG. 1 is formed.

After the bonded substrate stack is manufactured as described above, the first cutting step is performed (step C2). Specifically, the bonded substrate stack is cut along a predetermined cutting line. As a result, a plurality of medium-sized panel structures including a plurality of liquid crystal display panels 1 shown in FIG. 1 in which the liquid crystal inlet is exposed to the outside, so-called strip-shaped panel structures, are cut out. Then, after that, liquid crystal is injected into each liquid crystal display panel portion through each liquid crystal injection port, and after the injection is completed, the liquid crystal injection port is sealed with an ultraviolet curable resin (step C
3).

Then, in step C4, the strip-shaped panel structure is cut along a predetermined cutting line, whereby the liquid crystal display panel 1 shown in FIG. 1 is provided with the driving IC 10, the retardation plate and the polarizing plate. The ones that have not been cut are divided one by one. In the present invention, it is possible to use only a polarizing plate without mounting a retardation film, and in the case of a semi-transmissive reflective type or a transmissive type, a lower polarizing plate may be provided. It may be provided and can be applied to liquid crystal display panels of various forms.

After that, the driving IC 10 is mounted on the surface of the projecting region 4 by using ACF (step C5). The alignment at that time is performed using the above-mentioned IC side alignment mark and substrate side alignment mark. That is, the first
In the case of the embodiment, the driving IC 10 is arranged on the lower substrate 2 so that the substrate-side alignment mark 17 is at a predetermined relative position with respect to the IC-side alignment mark (not shown). Further, in the case of the second embodiment, the driving IC 10 is arranged with respect to the lower substrate 2 so that the IC side alignment mark 27 is located inside the transparent portion 25 of the substrate side alignment mark 25. Positioning work is CC
After detecting the respective alignment mark position coordinates with a D camera or the like, the driving IC is arranged on the liquid crystal display panel substrate by a transfer robot or the like.

Next, a retardation plate is attached to the upper substrate 3 facing the lower substrate 2 on which the driving IC 10 is mounted (step C6). Subsequently, polarizing plates are attached to the upper substrate 2 and the lower substrate 3, respectively (step C7). Finally, a reflection plate is attached to the lower substrate 2 (step C8) to complete the liquid crystal display device.

The configuration of the liquid crystal display device described above is merely an example, and the present invention can be applied to liquid crystal display devices of various configurations other than this.

[Application Example] In the above embodiment, the present invention is applied when the driving IC is mounted on the liquid crystal display panel substrate by the COG method.
The present invention can also be applied to mounting a driving IC using an FPC board. That is, when the drive IC is attached to the FPC board, the board-side alignment mark as described above is formed on the wiring formed on the FPC board, and the FPC board and the drive IC can be aligned with each other. . Further, also when connecting the FPC board and the liquid crystal display panel, a board-side alignment mark is similarly formed in the wiring formed on the FPC board side, and the alignment mark on the liquid crystal display panel side is utilized. , FPC
It is possible to align the substrate and the liquid crystal display panel.

The present invention is based on TFD (Thin Film Diod).
Two-terminal switching element and TFT represented by e)
The present invention can be applied to any active matrix type liquid crystal display device using a three-terminal type switching element represented by (Thin Film Transistor), and can also be applied to a passive matrix type liquid crystal display device having no switching element. .

[Electronic Equipment] Next, electronic equipment using the liquid crystal display device to which the present invention is applied will be described.

First, the liquid crystal display device to which the present invention is applied,
An example applied to a display unit of a portable personal computer (so-called notebook computer) will be described. Figure 5
FIG. 3A is a perspective view showing the configuration of this personal computer. As shown in the figure, the personal computer includes a main body portion 412 having a keyboard 411 and a display portion 413 to which the liquid crystal display device according to the present invention is applied.

Next, an example in which the liquid crystal display device according to the present invention is applied to the display portion of a mobile phone will be described. Figure 5
FIG. 3B is a perspective view showing the configuration of this mobile phone.
As shown in the figure, the mobile phone has a plurality of operation buttons 4
In addition to No. 21, an earpiece 422, a mouthpiece 423, and a display unit 424 to which the electro-optical device according to the invention is applied.

As the electronic equipment to which the liquid crystal display device according to the present invention can be applied, in addition to the personal computer shown in FIG. 5 (a) and the mobile phone shown in FIG. 5 (b), a liquid crystal television, A viewfinder type / monitor direct-viewing type video tape recorder, a car navigation device, a pager, an electronic notebook, a calculator, a word processor, a workstation, a videophone, a POS terminal, a digital still camera and the like can be mentioned.

[Brief description of drawings]

1 shows a liquid crystal display panel according to an embodiment of the present invention, FIG. 1 (a) is a plan view of the liquid crystal display panel 1, and FIG. 1 (b) is a liquid crystal display panel 1 shown in FIG. 1 (a). A-
It is sectional drawing in A '.

FIG. 2 is a diagram showing an example of formation of substrate-side alignment marks of the liquid crystal display panel according to the first embodiment of the present invention, and FIG. 2 (a) is a lower substrate of the liquid crystal display panel shown in FIG. 1 (a). 2 (b) is a sectional view taken along the line BB ′ of FIG. 2 (a), and FIG. 2 (c) is a sectional view taken along the line CC ′ of FIG. 2 (a).

FIG. 3 is a diagram showing an example of formation of substrate-side alignment marks of a liquid crystal display panel according to a second embodiment of the present invention, and FIG. 3 (a) is a lower substrate of the liquid crystal display panel shown in FIG. 1 (a). 3 (b) is a sectional view taken along the line DD 'in FIG. 3 (a), and FIG. 3 (c) is a sectional view taken along the line EE' in FIG. 3 (a).

FIG. 4 is a flowchart showing a manufacturing method of an example of a liquid crystal display device to which the present invention is applied.

FIG. 5 is an example of an electronic device to which the liquid crystal display device of the present invention is applied.

[Explanation of symbols]

1 Liquid crystal display panel A few transparent substrates 4 Overhang area 5 Seal material 6 display area 7 liquid crystal 10 Driving IC 11 terminals 12 wiring 15 APC 17, 24 Substrate side alignment mark 25 IC side alignment mark

Claims (8)

[Claims] 1. An electro-optical panel comprising wiring for electrical connection with an object to be mounted, and an alignment mark provided in the wiring. 2. The electro-optical panel according to claim 1, wherein the alignment mark is formed of a metal material forming the wiring. 3. The wiring is AP as the metal material.
The electro-optical panel according to claim 2, comprising C and ITO formed on the APC. 4. The electro-optical panel according to claim 2, wherein the alignment mark includes a transparent portion where the metal material layer is not formed. 5. An electro-optical device comprising the electro-optical panel according to claim 1. Description: 6. An electronic apparatus comprising the electro-optical device according to claim 5 as a display unit. 7. A method for manufacturing an electro-optical panel, which comprises the step of simultaneously forming a wiring and an alignment mark for electrical connection with a mounting object on a substrate. 8. The method of manufacturing an electro-optical panel according to claim 7, wherein the wiring and the alignment mark are formed as a film of the same metal material on the substrate.