JPH09251167A - Liquid crystal display element and its fabrication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To directly package an input bus board (PWB) to the chip parts of a COG(chip on glass) type liquid crystal display element mounted with the chip parts on its terminal part to this terminal part via a conductive adhesive. SOLUTION: The input bus board 12 including connecting lead parts capable of making surface-to-surface contact with the leader terminals 3b of the liquid crystal display element constituted by packaging the chip parts 6, such as liquid crystal driving circuits, on the leader terminals 3a, 3b of the terminal part 3 successively formed on one electrode substrate 1 is packaged via the UV curing resin 12 contg. conductive adhesives on the terminal part 3. The UV curing resin 12 is cured by irradiating the resin with UV rays from the backside of the terminal part 3, by which the input bus board 12 is integrally mounted on the terminal part 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method of manufacturing the same, and more particularly to a COG type liquid crystal display device in which a chip part such as a liquid crystal drive circuit is mounted on a terminal portion and a method of manufacturing the same. is there.

[0002]

2. Description of the Related Art First, referring to FIG. 4, COG (Chip
The structure of a liquid crystal display element of On Glass type will be schematically described. According to this, the liquid crystal display device includes two electrode substrates 1 and 2 having transparent electrodes 1a and 2a formed on one surface thereof. A terminal portion 3 is continuously provided on one electrode substrate 1 so as to protrude from the other electrode substrate 2, and a lead-out terminal 3a made of the same material as the transparent electrode 1a is provided on the terminal portion 3. Has been formed. On each transparent electrode 1a, 2a, an alignment film 4a, 4b made of, for example, an organic polymer film such as a polyimide resin is formed.
Are formed respectively.

The electrode substrates 1 and 2 are arranged so that their respective transparent electrodes 1a and 2a are opposed to each other with a sealing material 5 interposed therebetween, and a liquid crystal is enclosed in an empty cell formed by this. Then, a chip component (for example, a liquid crystal driving LSI) 6 is mounted on the lead terminal 3a of the terminal portion 3, and thereafter, an input wiring for the chip component 6 is provided.

[0004]

In that case, there is known a method of forming a sputtered film of Cr or Al on the terminal portion 3 and forming an input wiring by photoetching. The photoetching of the sputtered film is complicated in its process and is not preferable in terms of cost. Further, since the multi-layer wiring is difficult, the cross portion of the wiring is to be wire-bonded with a gold wire, but this method further increases the cost.

Therefore, as illustrated in FIG. 4, the input terminal 3b of the chip component 6 is formed at the same time as the lead terminal 3a at the end of the terminal portion 3, while the input wiring required for the chip component 6 is formed. They are formed on independent input bus boards 9 and are connected to each other via a flexible printed wiring board (FPC) 7. In this case, the both sides of the flexible printed wiring board 7 are connected to each other through the anisotropic conductive film 8 on the input side terminal 3b and the connector on the input bus board 9 side (not shown). Reference numeral 10 is a protective coat layer.

However, according to this, TAB (Ta
As in the pe Automated Bonding method, since the input bus board 9 is so-called externally attached, not only is the external dimension of the entire apparatus increased, but the input bus board 9 is connected to the terminal portion 3 via the flexible printed wiring board 7. Since it hangs down, it is undeniable that mechanical loads concentrate on the connection parts on both sides of it, causing problems such as peeling and disconnection.

However, in order to prevent this, a rigid printed circuit board (P
As WB), it may be directly mounted on the input side terminal 3b, but in order to ensure the electrical connection with the anisotropic conductive film 8, a high temperature of about 180 ° C. and 50 kg / square c.
A high pressure of about m is required.

However, in a normal PWB (a substrate in which a base material such as paper or glass cloth is impregnated with a resin), when exposed to such a high temperature and a high pressure, a crack is generated in the through hole and the wire breaks. It is not practical because there is a risk of As a countermeasure for this, for example, an FPC type substrate made of an epoxy material may be used, but this type of substrate is more expensive than the above-mentioned normal PWB and is difficult to accept in terms of cost. From such a thing,
At present, it is technically and costly difficult to directly mount the PWB on the terminal portion 3.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide a COG type liquid crystal display element having an input bus board which is a normal inexpensive board on its terminal portion. The object of the present invention is to provide a liquid crystal display element directly mounted with and a manufacturing method suitable for obtaining the liquid crystal display element.

[0010]

In order to achieve the above object, the invention of claim 1 is such that two electrode substrates, each having a transparent electrode formed on one surface thereof, sandwich the sealing material between the transparent electrodes. The liquid crystal is sealed between them so that they are opposed to each other, and a terminal portion having a lead terminal connected to the transparent electrode is continuously provided on the one electrode substrate. In a liquid crystal display element in which a chip component such as a liquid crystal driving circuit is mounted on the input bus substrate of the chip component including a connection lead portion capable of making surface contact with the lead terminal on the terminal portion, the input bus substrate is electrically conductive. It is characterized in that it is integrally provided via an ultraviolet curable resin containing particles.

According to this, since the input bus board is housed in the terminal portion, the overall size of the liquid crystal display device can be further reduced. Further, since the input bus board is integrally joined to the terminal portion, there is no possibility of disconnection of the wiring connection portion even if it receives vibration or impact, and high reliability is obtained.

In this case, the second aspect of the present invention is characterized in that the input bus board is a multi-layer board, which makes it possible to deal with the case where the input wiring to the chip component is complicated.

According to a third aspect of the present invention, in manufacturing the liquid crystal display element according to the first aspect, the input of the chip component includes a connection lead portion which is in surface contact with the lead terminal on the terminal portion. The bus substrate is mounted via an ultraviolet curable resin containing conductive particles, and ultraviolet rays are irradiated from the back surface side of the terminal portion to cure the ultraviolet curable resin.

According to this, connection can be performed at room temperature in terms of temperature, and the pressure applied to the connection is 10 kg /
It is less than a square cm. Therefore, as the input bus substrate, a usual inexpensive substrate in which a base material such as paper or glass cloth is impregnated with a resin can be used.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Next, in order to better understand the technical idea of the present invention, its embodiment (example) will be described with reference to FIGS. In this embodiment, the same reference numerals as those used in the conventional example shown in FIG.

FIG. 1 is a sectional view similar to FIG. 4 in which the terminal portion of the liquid crystal display element according to the present invention is enlarged. The terminal portion 3 of one electrode substrate 1 has a lead terminal 3a connected to the transparent electrode 1a. While the input side terminal 3b is formed,
A chip component 6 such as a liquid crystal drive LSI is surface-mounted on these terminals 3a and 3b, and its plan view is illustrated in FIG.

According to the present invention, the input bus board 11 for the chip component 6 is provided on the input side terminal 3b with the conductive adhesive material 1.
It is implemented through 2. This input bus board 11 is
It may be an inexpensive substrate in which a base material such as paper or glass cloth is impregnated with a resin material such as an epoxy resin or a phenol resin, and the surface opposite to the terminal portion 3 has a surface as shown in FIG. The connection lead portion 111 corresponding to each of the input side terminals 3b is formed.

On the opposite surface of the input bus board 11,
An external connection wiring pattern 112 having solder lands for connecting to an external controller (not shown) is formed. The connection lead portion 111 and the external connection wiring pattern 112 are connected to each other through internal wiring such as a through hole. However, since the input bus board 11 has a limited size, the internal wiring may be crossed. In this case, it is possible to deal with complicated wiring by using a multilayer substrate.

In this input bus board 11, each connection lead portion 111 is made to correspond to each input side terminal 3b on the terminal portion 3 side in a 1: 1 relationship, and a conductive adhesive 12 is applied between each of them. In this case, the conductive adhesive 12 is made of a UV curable resin mixed with conductive particles.

As described above, after the ultraviolet curable resin is applied between the connection lead portion 111 and the input side terminal 3b, the terminal portion is pressed from the input bus substrate 11 side with a jig such as a stainless bar. The input bus board 11 and the terminal portion 3 are firmly connected to each other by irradiating the resin from the back surface side (the lower side of the terminal portion 3 in FIG. 1) of 3 to cure the resin. As described above, according to the present invention, the connection at room temperature is possible, and the pressure applied to the input bus board 12 may be 10 kg / square cm or less. Therefore, an expensive heat-resistant board is used as the input bus board 12. No need to use.

The liquid crystal display device according to this embodiment in which the input bus substrate is integrated with the terminal portion as described above, and the conventional liquid crystal display in which the terminal portion is connected to the terminal portion via the flexible printed wiring board in a hanging state as shown in FIG. 1 for each of the elements
When a vibration test of 0G, 10 to 500 Hz was performed,
In the conventional liquid crystal display element, after 20 hours, disconnection (peeling) occurred at 10 of the connection points 22 by the anisotropic conductive film 8. On the other hand, in the liquid crystal display device according to the present invention, no disconnection was observed even after 30 hours.

In this embodiment and the conventional example, among the lead terminals formed on the terminal portion 3, the terminal portion on which the board is mounted is the input side terminal 3b, but this is for convenience of description. The input side terminal 3b is also a lead-out terminal.

[0023]

As described above, according to the invention of claim 1, since the input bus board is housed in the terminal portion, the size of the liquid crystal display device as a whole can be further reduced. Further, since the input bus board is integrally joined to the terminal portion, there is no possibility of disconnection of the wiring connection portion even if it receives vibration or impact, and high reliability is obtained.

Further, according to the invention of claim 2 in which a multi-layer board is used as the input bus board, in addition to the effect of claim 1, it is possible to deal with the case where the input wiring to the chip component is complicated. .

On the other hand, the input bus substrate of the chip component including the connection lead portion capable of making surface contact with the lead-out terminal (input side terminal) formed on the terminal portion is made of an ultraviolet curable resin containing conductive particles. According to the invention of claim 3, wherein the mounting is performed via the back surface of the terminal portion to irradiate ultraviolet rays to cure the ultraviolet curable resin, the connection can be performed at room temperature. , The pressure on that connection is 1
Less than 0 kg / square cm. Therefore, as the input bus substrate, a usual inexpensive substrate in which a base material such as paper or glass cloth is impregnated with a resin can be used.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view showing a part including a terminal portion of a liquid crystal display device according to the present invention.

FIG. 2 is a plan view showing an input bus board mounted on the terminal portion.

FIG. 3 is a plan view showing the terminal portion before mounting the input bus board.

FIG. 4 is a cross-sectional view similar to FIG. 1, showing an enlarged part including a terminal portion of a conventional liquid crystal display element.

[Explanation of symbols]

1, 2 Electrode substrate 1a, 2a Transparent electrode 3 Terminal part 3a Lead-out terminal 3b Input side terminal 4a, 4b Alignment film 5 Sealing material 6 Chip parts 11 Input bus board 12 Conductive adhesive (UV curable type containing conductive particles resin)

Claims (3)

[Claims] 1. A pair of electrode substrates, each having a transparent electrode formed on one surface thereof, are arranged with their transparent electrodes facing each other with a sealing material sandwiched therebetween, and a liquid crystal is sealed between them. On one of the electrode substrates, a terminal portion having a lead terminal connected to the transparent electrode is continuously provided, and in a liquid crystal display element in which a chip component such as a liquid crystal drive circuit is mounted on the lead terminal of the terminal portion, On the terminal portion, an input bus board of the chip component including a connection lead portion capable of making surface contact with the lead terminal is integrally provided via an ultraviolet curable resin containing conductive particles. A liquid crystal display device characterized by the above. 2. The liquid crystal display device according to claim 1, wherein the input bus substrate is a multilayer substrate. 3. Two electrode substrates, each having a transparent electrode formed on one surface thereof, are arranged so that the transparent electrodes face each other with a sealing material sandwiched therebetween, and a liquid crystal is sealed between them, and In the method of manufacturing a liquid crystal display element, wherein a terminal portion having a lead terminal connected to the transparent electrode is continuously provided on the electrode substrate of, and a chip component such as a liquid crystal drive circuit is mounted on the lead terminal of the terminal portion, The input bus substrate of the chip component including a connection lead portion capable of making surface contact with the lead-out terminal, is mounted via an ultraviolet curable resin containing conductive particles, from the back side of the terminal portion. A method for producing a liquid crystal display element, which comprises irradiating ultraviolet rays to cure the ultraviolet curable resin.