JPH0745065Y2 - Liquid crystal display element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a liquid crystal display element, and more particularly to improvement of a conductive paste for connecting respective transparent electrodes.

(B) Conventional Technology A conventional liquid crystal display element will be briefly described in detail with reference to FIG.

In FIG. 3, (1) shows In ₂ O ₃ , SnO on the glass substrate.
A transparent front electrode plate on which _{2 and the} like are deposited, (2) is a first front electrode arranged on the surface of the front electrode plate (1), and (3) is arranged on the surface of the front electrode plate (1). A second front electrode that constitutes an external terminal connected to an external electric circuit, (1) is a back electrode plate facing the front electrode plate (1), and (5) is a surface of the back electrode plate (4). Arranged above-mentioned first and second front electrodes (2)
A back electrode facing (3) through a predetermined space, (6) a sealing material provided around the front electrode plate by a printing method, (7)
Is provided inside the sealing material (6) and connects the second front electrode (3) and the back electrode (5) made of a conductive paint containing metal particles such as aluminum, silver, gold and tin. One of the second front electrode (3) and the back electrode (5), for example, a terminal portion of the back electrode (5), which is a conductive material, is provided in a dot shape at one point, and is connected to the front electrode plate (1). It is connected to the second front electrode (3) when it is adhered to the back electrode plate (4).

In the configuration as described above, the second front electrode (3) and the back electrode (5) are made of a conductive material (7) made of a conductive material containing metal particles such as aluminum, silver, gold and tin. Is formed, and both electrodes (3) and (5) are connected and conducted.

However, with the above conductive material, when the transparent electrode is oriented, or left in the air for a long time, the surface of the transparent electrode is oxidized and a Schottky barrier is formed at the contact interface between the transparent electrode and the conductive material. There is a problem in that the resistance of the part becomes large, uneven display occurs, and the yield of non-defective products is significantly reduced.

In order to solve the above-mentioned problems, it is well known that Ni powder is mixed into a conductive material to bring the interface between the transparent electrode and the conductive material into ohmic contact to improve the stability of conduction.

(C) Problems to be solved by the invention However, even in a conductive paste in which Ni is mixed in the conductive material, when the work function of the transparent electrode surface varies due to the progress of oxidation of the transparent electrode surface, Since the interface between the transparent electrode and the conductive paste does not form a sufficient ohmic contact, display unevenness is inevitably generated, and there is a problem of reduced yield.

(D) Means for Solving Problems The present invention has been made in view of the above problems.
As shown in FIG. 1, transparent electrodes (3) and (4) having a desired pattern are formed on the opposing surfaces of two transparent substrates (1) and (2) which are arranged to face each other. (4)
In a liquid crystal display element in which the conductive paste (5) is connected to the transparent paste, a transparent electrode (3) is provided in the conductive paste (5).
The problem is solved by mixing powder of the same material as (4).

(E) Action As described above, according to the present invention, by mixing the powder of the same material as the transparent electrodes (3) and (4) into the conductive paste (5), the transparent electrodes (3) and (4) are electrically conductive. The contact with the paste (5) can be ohmic contact and the contact resistance can be reduced.

(F) Embodiments The present invention will be described in detail below based on the embodiments shown in FIG.

As shown in FIG. 1, the liquid crystal display device of the present invention comprises two transparent substrates (1) and (2) and transparent electrodes (1) and (2) formed on the two substrates (1) and (2). , Transparent electrodes (3) and (4) for conducting the transparent electrodes (1) and (2) and a conductive paste (5) mixed with powder of the same material.

As the transparent substrates (1) and (2), a glass substrate which constitutes an ordinary LCD is used, and ITO transparent electrodes (3) and (4) are formed in a desired pattern on the upper surface thereof by a well-known technique.

Although not shown, an alignment film that has been subjected to an alignment treatment for aligning liquid crystal molecules is formed on the transparent electrodes (3) and (4).

As is well known, the transparent electrodes (3) and (4) formed on the respective transparent substrates (1) and (2) are electrically connected by a conductive material which is a conductive paste (5).

The feature of the present invention is that this conductive paste (5)
It is in. That is, the present invention mixes powder of the same material as the transparent electrodes (3) and (4) into the conductive paste (5).

The conductive paste (5) is usually Ag paste,
5 to 10 ωt% of ITO powder is mixed in the conductive paste (5).

ITO powder is In ₂ O ₃ (indium oxide) 50g, SnC1 ₄ · xH ₂ O
After mixing 6.25 g of (stannic chloride) and thoroughly mashing it with a dairy bee, etc., it was heated and reacted in an electric furnace at 800 ° C. for 2 to 3 hours, air-cooled, and then ground again with a dairy bee to form a powder. It

FIG. 2 shows the conductive paste which is the feature of the present invention and the conventional conductive paste (Ni is mixed in Ag paste).
It is the experimental data which shows the defective rate when leaving to stand at the temperature. As is apparent from FIG. 2, in the conventional conductive paste, defects occur from the time of production, and after 100 hours, the defect rate significantly increases. On the other hand, it is clear that the conductive paste of the present invention causes almost no defects even after 100 hours. This is because sufficient ohmic characteristics can be obtained even if the transparent electrode has a collapsed state.

As described in detail above, according to the present invention, the conductive paste (5) contains powder of the same material as the transparent electrodes (3) and (4).
By mixing the transparent electrodes (3) and (4) at a ratio of ˜50 ωt%, the ohmic characteristics are not deteriorated even if the surface of the transparent electrodes (3) and (4) is changed. The contact can be ohmic contact and the contact resistance can be reduced.

In this embodiment, the transparent electrodes (3) and (4) are formed of ITO, but other transparent electrodes can be formed by using SnO ₂ (nesa), ZnO (zinc oxide) and Cds (cadmium sulfide).
Even in such a case, if powder of the same material as the transparent electrode is mixed in the conductive paste, the same result as the data shown in FIG. 2 can be obtained.

(G) Effect of the Invention As described in detail above, according to the present invention, by mixing the powder of the same material as the transparent electrode into the conductive paste,
It is possible to reduce the contact resistance between the transparent electrode and the conductive paste, and it is possible to remarkably reduce the occurrence of display unevenness due to the contact resistance of the conductive paste that has been conventionally generated.

Further, according to the present invention, there is an advantage that defects due to display unevenness are almost eliminated and the yield is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a characteristic view of a conductive paste of the present invention, and FIG. 3 is a sectional view showing a conventional example. (1) and (2) are transparent substrates, (3) and (4) are transparent electrodes,
(5) is a conductive paste.

Claims (1)

[Scope of utility model registration request] 1. A liquid crystal display device in which transparent electrodes having a desired pattern are formed on opposite surfaces of two transparent substrates which are arranged opposite to each other, and the transparent electrodes are connected by Ag paste. A liquid crystal display device, characterized in that powder of the same material as that of the transparent electrode is mixed in to reduce contact resistance at a contact interface between the transparent electrode and the Ag paste.