JPH0145117Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a thin film EL panel, and more specifically to a thin film EL matrix type display panel that displays various information.

2. Description of the Related Art Thin film EL matrix type display panels generally have a glass package structure, and a specific example thereof will be explained with reference to FIGS. 11 and 12.
11 is a plan view, the left half of FIG. 12 is a cross-sectional view in the X direction, and the right half is a cross-sectional view in the Y direction perpendicular to the X direction.
A cross-sectional view of the direction is shown.

In the figure, 1 is a transparent glass substrate, and 2 is a matrix-type thin film formed on the glass substrate 1.
It is an EL element. In this EL element 2, reference numeral 3 denotes a large number of striped transparent electrodes formed by depositing ITO on the glass substrate 1 at fixed pitches in the The electrode terminal portion m for external extraction is formed by extending the electrode terminal portion m. 4 is a transparent first insulating layer such as _Y2O3 that covers the transparent electrode ₃ , and 5 is formed on the first insulating layer 4.
ZnS: A light-emitting layer such as Mn, 6 covers the light-emitting layer 5
A second insulating layer 7 of Y ₂ O ₃ etc. is Y on the second insulating layer 6.
A back electrode made of an Al vapor deposited film formed in a large number of stripes at regular pitches in the direction, and one end of each of these is extended to the opposite periphery of the glass substrate 1 for external extraction. An electrode terminal portion n is formed. Reference numeral 8 denotes an inverted dish-shaped cover glass for hermetically sealing the EL element 2 on the glass substrate 1, and its open end surface partially crosses the electrode terminal parts m and n on the peripheral edge of the glass substrate 1, and the epoxy It is also airtightly fixed with an insulating adhesive 9 such as resin. Reference numeral 10 denotes silicone oil, which is an insulating protective fluid, injected between the cover glass 8 and the EL element 2 through a through hole 11 formed in a part of the cover glass 8, and 12 represents a piece of glass that airtightly closes the through hole 11. Yes (Special Publication No. 59-2157).

Problems to be Solved by the Invention The cross-sectional shape of the electrode terminal parts m and n formed at regular pitches in the X-Y direction on the periphery of the glass substrate 1 is approximately rectangular, as shown in FIG. , its thickness is about 2000 Å, and the glass substrate 1 and the electrode terminal part m,
There is a step difference of about 2000 Å between it and n. Therefore, when the cover glass 8 is glued with the adhesive 9 across the electrode terminals m and n, the adhesive 9 does not completely cover the above-mentioned step, and a small gap g is created at the corner of the step. This may occur. Such a void g impairs the moisture-proofing effect of the EL element 2 by the cover glass 8, and shortens the life of the EL element 2. Therefore, some attempts have been made to increase the amount of adhesive 7 to suppress the occurrence rate of the voids g, but this is not very effective, and if the amount of adhesive 9 is increased, Excess material protrudes into and out of the cover glass 8,
It may worsen the appearance or impair the generation characteristics.

Therefore, the purpose of this invention is to
The objective is to improve the airtightness of the cover glass around the substrate periphery, which hermetically seals the EL element, and to increase the moisture-proofing effect.

Means for Solving the Problems The present invention aims to achieve the above-mentioned purpose by providing an external lead-out electrode terminal portion of each electrode of a matrix-type EL element formed on a substrate, which is formed by extending over the peripheral edge of the substrate. In the case where a cover glass is fixed across the substrate via an insulating adhesive, an insulation is provided between at least the EL element electrode terminal portion of the portion of the peripheral edge of the substrate where the cover glass is to be fixed, to eliminate the level difference between the substrate and the terminal. This is achieved by selectively depositing a film in advance.

Function: The insulating film selectively formed on the peripheral edge of the substrate in the present invention fills the level difference between the EL element electrode terminal part on the peripheral edge of the substrate and the substrate, and makes the area where the cover glass is to be fixed completely free from any level difference. It has the effect of forming a smooth surface with few steps, and as a result, the cover glass can be fixed to the substrate with good airtightness using a small amount of adhesive.

Embodiment Hereinafter, an embodiment in which the present invention is applied to a thin film EL matrix type display panel of the same type as that shown in FIG. 11 will be described with reference to FIGS. 1 to 3.
In addition, in FIGS. 1 to 3, the same reference numerals are given to the same parts as in FIGS. 11 and 12,
Explanation will be omitted.

A feature of the thin film EL panel illustrated in FIGS. 1 to 3 is that the thickness between the electrode terminal portions m and n of the portion A to be fixed to the cover glass on the glass substrate 1 is approximately the same as that of the electrode terminal portions m and n. By now depositing the insulating film 13, the cover glass 8 is fixed onto the insulating film 13 and the electrode terminal portions m and n via the adhesive 9. The insulating film 13 is a vapor deposited film, sputtered film, etc. made of an insulating material such as Al ₂ O ₃ or SiO ₂ with good density.
Such an insulating film 13 is, for example, shown in FIGS. 4 to 8.
It is formed by the steps shown in the figure.

First, the EL element 2 is formed on the glass substrate 1, and then a resist film 14 is applied by spin-on method or the like, as shown in FIGS. Paint with. This resist film 14 is formed to have a thickness approximately 10 times that of the electrode terminal portions m and n. Next, a mask 15 is placed over the position indicated by the chain line in FIG. 5, and the resist film 14 is selectively exposed to light and developed using a photolithography method, as shown in FIG. Leave only on m and n and remove the others.
Next, as shown in FIG. 7, an insulating material such as Al ₂ O ₃ or SiO ₂ is grown on the area A where the cover glass is to be fixed by vapor deposition, sputtering, CVD, etc. Insulating films 13 and 13' are formed on the glass substrate 1 and on the resist film 14 remaining on the electrode terminal parts m and n in the same portion A to have the same thickness as the electrode terminal parts m and n. At this time,
Since the resist film 14 is formed sufficiently thicker than the electrode terminal parts m and n, the insulating film 13 between the electrode terminals and the insulating film 13' on the resist film 14 are discontinuous, resulting in a so-called broken state. It's getting old. Thereafter, when the resist film 14 in FIG. 7 is dissolved and removed with an organic solvent, the insulating film 13' thereon is also removed at the same time, and as shown in FIG. Insulating film 13 between
You will get what is filled with.

By forming the above-mentioned insulating film 13 with Al ₂ O ₃ , SiO ₂ or the like having good density, the insulating film 13 can be formed with sufficient sealing properties even on the corner parts of the glass substrate 1 and the electrode terminal parts m and n. . By making the insulating film 13 about the same thickness as the electrode terminal parts m and n, the part A where the cover glass is to be fixed, which crosses the insulating film 13 and the electrode terminal parts m and n, becomes a gentle surface with almost no steps. Therefore, as shown in FIGS. 2 and 3, the cover glass 8 can be firmly and airtightly fixed onto the portion A where the cover glass is to be fixed even with a small amount of adhesive 9.

9 and 10 are for explaining a second embodiment of the present invention, in which an insulating film 16 is formed on a portion A of a glass substrate 1 to which a cover glass is to be fixed, including on electrode terminal portions m and n. is formed with a thickness such that the upper surface is a gentle surface with few steps.
This insulating film 16 is made of Al ₂ O ₃ or SiO ₂ , and its thickness is approximately five times that of the electrode terminal portions m and n. In this embodiment, a cover glass 8
Since the upper surface of the insulating film 16 is smooth, the cover glass 8 can be fixed in a sufficiently airtight manner with a small amount of adhesive.

Effects of the invention According to the invention, the influence of the difference in level between the electrode terminal part of the EL element and the substrate is reduced, and the airtightness of the bond between the cover glass and the substrate, which seals the EL element on the substrate, is increased. This further improves the moisture-proofing effect of the EL element by the cover glass, extending the life of the EL element, and since only a small amount of adhesive is required, there are no problems caused by the adhesive protruding in or out.

[Brief explanation of the drawing]

Fig. 1 is a plan view with some omitted parts showing an embodiment of the thin film EL panel according to the present invention, Fig. 2 is an enlarged sectional view taken along line T ₁ - _{T 1} of Fig. 1, and Fig. 3 is FIG. 2 is a partial sectional view taken along the line T ₂ -T ₂ , FIGS. 4 to 8 are for explaining the manufacturing process of the panel shown in FIG. 1, and FIG. 4 is a partial plan view of the substrate, FIG. 5 is an enlarged sectional view taken along the line T ₃ -T ₃ in FIG. 4, and FIGS. 6 to 8 are sectional views of the substrate at each manufacturing process.
FIG. 9 is a partial sectional view showing another embodiment of the present invention;
FIG. 10 is a partial sectional view taken along the line T ₄ -T ₄ in FIG. 9. FIG. 11 is a plan view of a conventional thin-film EL panel, including some omitted parts, and FIG. 12 is an enlarged cross-sectional view of the panel in FIG. 11, with the left half being a cross-sectional view in the X direction;
The right half is a sectional view in the Y direction, and FIG. 13 is an enlarged sectional view of the peripheral edge of the panel in FIG. 11. 1... Substrate, 2... EL element, 3, 7... Electrode,
m, n... Electrode terminal portion, 8... Cover glass, 9
... Adhesive, 13, 16 ... Insulating film, A ... Part to be fixed to cover glass.

Claims (1)

[Claims for Utility Model Registration] An insulating adhesive is applied across the external lead-out electrode terminals of each electrode of a matrix-type EL element formed on a substrate, extending over the peripheral edge of the substrate. In the case where the cover glass is fixed through the substrate, an insulating film is selectively applied in advance at least between the EL element electrode terminal portions of the portion of the peripheral edge of the substrate where the cover glass is to be fixed, to eliminate the level difference between the substrate and the electrode terminal portions. A thin film EL panel characterized by the