JP3142622B2 - Display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device having a driving circuit pattern on the periphery of a display portion of a substrate.

[0002]

2. Description of the Related Art In recent years, as a mounting structure of a display device having a driving circuit pattern on the periphery of a display unit, for example, using an active matrix type display element, a driving IC (Integrated
Circuit) directly mounted on the above driving circuit pattern
The OG (Chip On Grass) method has been put to practical use by some manufacturers.

[0003] Display devices employing the COG method include:
For example, as shown in FIG.
Are provided to face each other, and a drive IC 28 is mounted on an extended portion of one of the insulating substrates 21. Drive IC 28
Has an output terminal (not shown) connected to a terminal of an electrode pattern provided on the insulating substrate 21, and an input terminal (not shown) connected to a drive signal input wiring 26. The drive signal input wiring 26 is connected to a circuit board connecting portion 27 for inputting an external signal provided at an end of the insulating substrate 21.

Further, an external signal input circuit board 29 is adhered to each of the sides of the circuit board connecting portion 27 by using an anisotropic conductive adhesive (not shown). From the input circuit board 29 through the circuit board connection portion 27 and the drive signal input wiring 26, the driving IC 2
An external signal such as a power supply and a control signal is supplied to 8.

Further, as the above-mentioned active matrix type display device is commercialized, cost reduction is strongly desired. Therefore, conventionally, a display device as shown in FIG. 6 or FIG. 7 has been proposed for the purpose of reducing costs and simplifying the mounting process by reducing the driving IC mounting area on the insulating substrate 1.

That is, in the display device shown in FIG. 6, a circuit board connecting portion 27 for inputting an external signal is collectively provided on one side of the insulating substrate 21, and on the side where the circuit board connecting portion 27 is not provided, The drive signal input wiring of the drive IC 28 is controlled by a bus line 25 using a through hole or the like, and is connected to a circuit board connection portion 27 provided on an adjacent side. As described above, since the circuit board connecting portions 27 are provided concentratedly on one side of the insulating substrate 21, it is possible to collectively connect the driving ICs 28 to one circuit board 29, and mount the driving ICs. Area reduction has been achieved.

[0007] In the display device shown in FIG.
A bus line 25 is provided for each side of the insulating substrate 21 provided with 28. Therefore, the bus line 25
Is connected to each of the circuit board connecting portions 27 to which the insulating substrate 21 is connected.
And the circuit board 29 can be reduced accordingly.
It is possible to further reduce 28 mounting areas.

[0008]

However, a display address element (not shown) is also formed on the insulating substrate 21 on which the drive signal input wiring 26 and the bus line 25 are formed. The wiring material for forming the driving circuit pattern including the wiring 26 and the bus line 25 is usually the wiring material used for forming the display address element. Therefore, depending on the type of wiring material forming the drive circuit pattern, as shown in FIG. 6 or FIG.
When the length of the driving circuit pattern up to the above differs for each driving IC 28, a wiring resistance difference occurs for each driving IC 28, and a problem arises that a display difference occurs.

The display device of the present invention has been made in view of the above-mentioned conventional problems, and realizes cost reduction and simplification of a mounting process by reducing a mounting area without causing a display difference due to a wiring resistance difference. It is intended to provide a possible display device.

[0010]

In order to solve the above-mentioned problems, a display device according to the present invention includes a first substrate having a driving circuit pattern formed on a periphery of a display portion, and a display device facing the first substrate. In the display device having the second substrate provided, the external signal input wiring for connecting the driving circuit pattern on the first substrate and a circuit board connecting portion for inputting an external signal is provided in the second device. It is characterized in that it is formed on the surface of the substrate facing the first substrate at the periphery of the display section.

[0011]

According to the above arrangement, the driving circuit pattern provided on the first substrate is connected to the circuit board connecting portion via the external signal input wiring formed on the periphery of the display portion on the second substrate. It will be connected.

Since the external signal input wiring is formed on the second substrate, the material of the external signal input wiring is not limited as in the prior art, and can be formed using a low resistance wiring material. is there. Therefore, for example, a plurality of drive circuit patterns are provided on the first substrate, and the circuit board connection portion is provided on the first substrate for the purpose of cost reduction or simplification of the mounting process.
By being provided collectively on one side of the substrate, even if a difference occurs in the distance from each drive circuit pattern to the circuit board connection portion, there is almost no difference in wiring resistance for each drive circuit circuit pattern.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. 1 to 4, taking an active matrix type liquid crystal display device as an example.

As shown in FIG. 1, the liquid crystal display device of this embodiment has a pair of insulating substrates (first and second substrates) 1 made of glass, PES (Polyether Sulphone), acrylic resin, or the like. 2 are arranged to face each other. On the surface of the lower insulating substrate 1 facing the upper insulating substrate 2,
A display address element (not shown) is provided for each pixel. Also, a lower insulating substrate 1 and an upper insulating substrate 2
An electrode pattern, an alignment film, and the like are formed on each of the opposed surfaces, and the lower insulating substrate 1 and the upper insulating substrate 2 are adhered to each other with a sealing material (not shown) while leaving a gap for a liquid crystal layer. Have been combined.

The upper insulating substrate 2 is cut off at two adjacent ends in order to expose terminals of an electrode pattern provided on the lower insulating substrate 1. Therefore, the ends of the two sides of the lower insulating substrate 1 corresponding to the cut two sides of the upper insulating substrate 2 are formed as the extended portions 1a and 1b. These extended portions 1a and 1b have drive I
C mounting circuit patterns (driving circuit patterns) 4 are provided at two locations per side. The above drive IC
The mounting circuit pattern 4 is not limited to two locations, but may be singular or two or more locations. Driving IC provided on extended portion 1a on the long side of lower insulating substrate 1
The drive signal input wirings (drive circuit patterns) 6 of the mounting circuit pattern 4 are provided at the ends of the extended portions 1a in accordance with the number of the drive signal input wirings 6 as well. Each is connected to the board connection part 7.

On the other hand, on the peripheral portion 2b formed so as to surround the display section 2a on the surface facing the lower insulating substrate 1 on the upper insulating substrate 2, the upper insulating substrate 2 is illustrated. Simultaneously with the formation of the light-shielding mask (black mask), the external input bus line (wiring for external signal input) 5 made of Al or the like as a low-resistance wiring material is parallel to the extending portion 1b of the lower insulating substrate 1. Is formed.

The drive signal input wiring 6 connected to the drive IC mounting circuit pattern 4 on the extension portion 1b of the lower insulating substrate 1 is shown in FIGS. 2A and 2B and FIG. a) As shown in (b), the end of the external input bus line 5 is placed under the upper insulating substrate 2 via an anisotropic conductive adhesive 9 or an adhesive such as an Al paste. It is connected. That is, the extension portion 1 of the lower insulating substrate 1
The drive signal input wiring 6 in b is controlled by the external input bus line 5 and is connected to the circuit board connecting portion 7 provided on the extension 1a of the lower insulating substrate 1 respectively.

In the above configuration, a drive IC (not shown) is connected to each of the drive IC mounting circuit patterns 4, and a circuit board (not shown) for inputting an external signal is connected to the circuit board connecting portion 7. External signals such as a power supply and a control signal are supplied from the circuit board to the drive IC via the circuit board connection portion 7, the external input bus line 5, and the drive signal input wiring 6, so that the liquid crystal display device is driven. It has become.

As described above, in the liquid crystal display device of the present embodiment, the external input bus line 5 for controlling the drive signal input wiring 6 connected to the drive IC mounting circuit pattern 4 on the lower insulating substrate 1. Are formed on the peripheral portion 2 b on the surface facing the lower insulating substrate 1 with the upper insulating substrate 2.

Therefore, the selection of the wiring material for forming the external input bus line 5 is not restricted as in the prior art, and the external input bus line 5 can be formed using a low-resistance wiring material such as Al. Even if a difference in distance to the circuit board connecting portion 7 occurs for each drive IC connected to
It is possible to reduce the wiring resistance difference generated between the driving ICs. Thereby, for the purpose of reducing the cost of the liquid crystal display device or simplifying the mounting process, the circuit board connecting portion 7 for inputting an external signal is collectively formed on one side of the lower insulating substrate 1, and the mounting area is reduced. Even in the case of reduction, the occurrence of a display difference due to a wiring resistance difference for each drive IC is suppressed.

The external input bus lines 5 formed on the upper insulating substrate 2 can be formed simultaneously with the light shielding mask (black mask) on the upper insulating substrate 2. In forming, there is no need to add new materials or manufacturing processes.

In this embodiment, the driving IC mounting circuit pattern 4 is formed on the extending portions 1a and 1b of the lower insulating substrate 1, and the driving IC mounting circuit pattern 4 is formed on the driving IC mounting circuit pattern 4.
4, the driving IC 8 is formed on the lower insulating substrate 1 and the driving IC 8 is mounted on the peripheral portion 2a of the upper insulating substrate 2 as shown in FIG.
The external input bus line 5 that connects the driving ICs 8 collectively is also formed of a low-resistance wiring material such as Al, and the lower insulating property of the display portion peripheral edge 2a of the upper insulating substrate 2 is also covered. The present invention can be applied by forming it on the surface facing the substrate 1 and connecting it to the circuit board connecting portion 7.

Further, in this case, since the external input bus line 5 is formed for each side where the driving IC 8 is formed, the circuit board connecting portion 7 is connected to the extended portion of the lower insulating substrate 1. It can be formed collectively at one corner in 1a. Therefore, not only the display difference or the like is suppressed, but also the mounting area can be further reduced.

[0024]

As described above, according to the display device of the present invention, the external signal input wiring for connecting the driving circuit pattern on the first substrate and the circuit board connecting portion for inputting the external signal is formed by : This is a configuration in which the periphery of the display section of the second substrate is formed on the surface facing the first substrate.

Therefore, the external signal input wiring can be formed on the second substrate using the low-resistance wiring material, so that the mounting area can be reduced for the purpose of cost reduction or simplification of the mounting process. In this case, even if there is a difference in the distance to the circuit board connection part for each driving circuit pattern, the wiring resistance difference for each driving circuit pattern can be reduced, and the display that occurs due to the wiring resistance difference can be reduced. There is an effect that the difference can be suppressed.

[Brief description of the drawings]

FIG. 1 is a plan view showing an active matrix type liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a main part plan view showing a connection state between a drive signal input wiring and an external input bus line in the liquid crystal display device.

FIG. 3A is a diagram illustrating a liquid crystal display device shown in FIG.
FIG. 2B is a cross-sectional view taken along a line A, and FIG.

FIG. 4 is a plan view illustrating a liquid crystal display device according to another embodiment of the present invention.

FIG. 5 is a plan view showing a mounting structure of a drive IC and a circuit board for inputting external signals in a conventional display device.

FIG. 6 is a plan view showing a mounting structure of a driving IC and a circuit board for inputting an external signal in another conventional display device.

FIG. 7 is a plan view showing a mounting structure of a driving IC and a circuit board for inputting an external signal in still another conventional display device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 Lower insulating substrate (first substrate) 1 a, 1 b Extended portion (peripheral edge of display unit) 2 Upper insulating substrate (second substrate) 2 b Peripheral edge (peripheral edge of display unit) 4 Circuit pattern for mounting driving IC (for driving Circuit pattern) 5 External input bus line (External signal input wiring) 6 Drive signal input wiring (Drive circuit pattern) 7 Circuit board connection

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1345 H05K 1/14 G09F 9/00 348

Claims (1)

(57) [Claims] 1. A first substrate having a driving circuit pattern formed on the periphery of a display portion, and a first substrate disposed opposite to the first substrate.
In a display device having two substrates, an external signal input wiring for connecting a driving circuit pattern on the first substrate and a circuit substrate connecting portion for inputting an external signal is provided on a display portion of the second substrate. A display device, wherein the display device is formed on a surface of the periphery facing the first substrate.