JPH01236596A - Manufacture of thin film el panel - Google Patents

Abstract

PURPOSE:To improve display quality by providing the structure not using the transference electrode in which the substrate directly laminated to the aluminum composing a back plate is composed of oxide. CONSTITUTION:The adhesion of an Al film is unlowered and ZnS:Mn, etc., is difficult to be melted since a back plate 20 is formed by the alkaline wet etching method of photolithography. I.T.O. that is a transference electrode 16 and Al are not directly laminated in this structure by laminating Al in the area of the laminated layer part 21 of the back plate. This enables display quality to be improved with the black deterioration of the I.T.O. that is the electrode 20 utterly unoccurring, and the disconnection of the electrode 16 composed of the I.T.O. also unoccurring.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a thin film EL display panel that displays information such as characters and graphics in a dot matrix.

An example of the structure of a thin FF1EL matrix type display panel will be described with reference to FIG. 2. The right half of Figure 2 is a cross-sectional view in the X direction, and the left half is a cross-sectional view in the Y direction perpendicular to the X direction.
It is a sectional view of the direction. In FIG. 2, 1 is a glass substrate which is a transparent substrate, and 2 is a matrix type thin film EL element formed on this glass substrate 1. In FIG.

3 in this thin film EL element 2 is placed on the glass substrate 1 at lT, 0. A transparent electrode group formed in a large number of stripes with a constant pitch in the Y direction in the longitudinal direction and in the X direction by a vapor deposition method,
4 has Alzo3 or Y on the transparent electrode 4 and the glass substrate 1.
A transparent first insulating layer made of 2O3 or the like by vapor deposition or sputtering; 5 is a light emitting layer made of ZnS:Mn or the like formed by vapor deposition on the first insulating layer 4; 6 is a light emitting layer on this light emitting layer 5; Aλ to
z A transparent second insulating layer formed of Os, Y2O3, etc. by vapor deposition or sputtering, 7 is a large number of stripes 4K formed on the second insulating layer with the X direction in the longitudinal direction and the Y direction at a constant pitch.
This is a back electrode made of an Al1 vapor-deposited film formed on the substrate. Note that this back electrode 7 is formed by photolithographic lift-off method,
Alternatively, it is formed into a stripe shape by acid wet etching. Reference numeral 8 denotes an inverted dish-shaped cover glass which is fixed onto the glass substrate 1 via an adhesive 9 to hermetically seal the thin film EL element 2, and together with the glass substrate 1 constitutes an envelope 10. Reference numeral 11 denotes an insulating protective fluid such as silicone oil filled inside the envelope 10 in order to improve the moisture resistance of the thin film EL element 2, and is injected through a through hole 12 formed in a part of the cover glass 8. After this injection, the through hole 12 is closed with a cover plate 13 (Japanese Patent Laid-Open No. 57-7088).

In this thin film EL matrix type display panel, the transparent electrode 3 and the back electrode 7 intersect in a matrix as shown in FIG. 3 to form a large number of matrix pixels mm. This transparent electrode 3 and the extending end 3a of the back surface 3.7,
When a driving voltage is selectively applied between the picture electrodes 3 and 7a,
The pixel portions of the light emitting layer 5 where the dots intersect selectively emit light to display desired information in a dot matrix.

By the way, when forming the back electrode 7 of the thin film EL element 2, conventionally, a photolithography lift-off method or an acid wet etching method has been used. After lithography, the back electrode 7 is layered by vapor deposition, so the temperature range during AI film formation is narrow, the adhesion of the AQ film is reduced, and dielectric breakdown is likely to occur, resulting in poor display quality. In the case of photolithography's acid wet etching method, foreign matter and secondary
When pinholes occur in the A9 film that is the insulating layer 6 and the back electrode 7, the ZnS:Mn, etc. that are the light emitting layer 5 are dissolved during acid wet etching, easily causing dielectric breakdown, which deteriorates display quality. There was a problem with the decline.

Therefore, as a means to solve the above-mentioned problems, there is a method in which the back electrode 7, ie, AQ, is formed in stripes by an alkali wet etching method of photophosphorography. In this method, the back electrode 7 is laminated by a vapor deposition method, photolithography is performed, and alkali wet etching is performed.This allows the light-emitting layer 5 to be formed without reducing the adhesion of the Afl film. Some ZnS:
Display quality can be improved by making it difficult to dissolve Mn and the like.

However, when Afl, which is the back electrode 7, and 1, T, and O, which are the transparent electrodes 3, are directly laminated, when performing alkaline wet etching, all of the laminated parts are 1
．． T, O, and A2 always turn black and deteriorate, forming a striped pattern. There was a problem in that the T, O, film was disconnected, which significantly reduced the display quality.

The present invention (2) was proposed in view of the above-mentioned problems, and technical means for solving the above-mentioned problems are as follows:
When it is formed into a stripe shape using an alkali wet etching method of photolithography, the structure is such that the underlying layer of the mosquito membrane layer avoids a transparent electrode made of an oxide.

According to the thin film EL panel according to the present invention, the back electrode A2 is formed by the alkaline wet etching method of photolithography, and the base of the two-layer laminated part avoids a transparent electrode made of an oxide. The structure prevents dielectric breakdown from occurring, and the transparent electrode made of oxide and A9. The display quality can be improved by preventing deterioration of the back electrode.

An embodiment of the method for manufacturing a thin film EL panel according to the present invention will be described with reference to FIG. Note that FIG. 1a is a plan view, and FIG. 1b is a partially enlarged sectional view in the X direction. In FIG. 1, 14 is a glass substrate which is a light-transmitting substrate, and 15 is a thin film EL element formed on this glass substrate 14. In this thin film EL element 15, 16 is a transparent electrode formed on the glass substrate 14 in the form of a large number of stripes of 1.7. Ac on the electrode 16 and glass substrate 14
A transparent first insulating layer 18 formed of 2O3, Y2O3, etc. by vapor deposition or sputtering is formed on this first insulating layer 17.
nS: a light emitting layer formed of Mn or the like by vapor deposition, 19 a transparent second insulating layer formed of kfLzOs, Y2O3, etc. by vapor deposition or sputtering on this light emitting layer 18, 20 this second insulating layer A9 on layer 19. Laminated by vapor deposition method etc.
The back electrode is formed into a large number of stripes at regular pitches in the X direction, with the X direction being an elongated plane, using an alkali wet etching method of photolithography. This back electrode 20 is formed by photolithographic alkali wet etching method, so that it does not reduce the adhesion of the λσ film and does not dissolve ZnS:Mn etc. (this improves display quality). In addition, by laminating All in the range of the laminated portion 21 of the back electrode shown in FIG. As a result, I , T , 0 which is the transparent electrode 16 and A which is the back electrode 20
No black deterioration of 9 occurred at all, and 1. The display quality was improved without disconnection of the transparent electrode 16 made of T and O.

Incidentally, as shown in FIG. 1, the extending end of At, which is the back electrode 20, extends along the X direction, and is a terminal portion on the back electrode side arranged at a certain pinch in the X direction. 22, and as in the conventional case, a flexible lead for leading out the electrodes of the thin film EL element 15 is formed by adhering a large number of external leads such as copper foil to a plastic film, and an external lead on the back electrode side. The terminal portion 22 is electrically and mechanically connected by solder. In this case, the terminal portion 22 is formed by sequentially laminating T1 as the lower layer 22a, At as the intermediate layer 22b, and N1 as the upper layer 22c by vapor deposition or the like on the glass substrate 14, which is a transparent substrate. As a result, Al1, which is the back electrode 20, is 1. It can be taken out to the external lead without being directly laminated with T, O, etc., and the black color of A is not deteriorated, and the reliability of the back electrode 20 is improved.

In the above embodiment, the back electrode terminal portion 22 is formed by sequentially laminating TI as the lower layer 22a, AQ as the intermediate layer 22b, and N1 evaporation method as the upper layer 22c. The upper layer part 22c of the terminal part 22 which is directly laminated with AI 20 is .

T, 0. For example, the terminal part 2 may have a structure that avoids
2 is made into a two-socket structure, first, I , T , and 0 are formed on the glass substrate 14, which is a transparent substrate, by vapor deposition or the like, and then N1 is formed on this by plating or the like. It may be formed to cover T and O.

IE and Yuri - According to the method of manufacturing a thin film EL panel according to the present invention, the back electrode A& is formed by alkaline wet etching of photolithography, etc., so that the adhesion of the All film is not reduced, and ZnS: To dissolve Mn etc.
This improves the display quality and makes it possible to improve the display quality.
By avoiding the use of a transparent electrode made of an oxide as the base directly laminated with the oxide, deterioration of the transparent electrode made of At and oxide is prevented, and display quality is improved.

[Brief explanation of the drawing]

FIG. 1A is a plan view showing an embodiment of a thin film EL panel for explaining the manufacturing method of the present invention, and FIG. 1 is a partially enlarged sectional view in the X direction. FIG. 2 is a sectional view showing an example of the structure of a conventional thin film EL panel, with the right half being a sectional view in the X direction, and the left half being a sectional view in the X direction. FIG. 3 is a partially enlarged plan view showing a pixel portion in a thin 1iEL panel. 14... Transparent substrate (glass substrate), 15... Thin film EL element, 16... Transparent electrode, 17... First insulating layer, 18... Light emitting layer, 19... Second 20... Back electrode, 21... Laminated portion of back electrode, 22... Terminal portion on the back electrode side. X--11-------X X X m 2 Figure 3r51J

Claims (1)

[Claims] A thin film EL device comprising a striped transparent electrode, a first insulating layer, a light-emitting layer, a second insulating layer, and a striped back electrode stacked one after another on a light-transmitting substrate. In the method for manufacturing a thin film EL panel, the aluminum constituting the back electrode is formed into a stripe shape by an alkali wet etching method of photolithography, wherein the base layer directly laminated with the aluminum constituting the back electrode is made of an oxide. A method for manufacturing a thin film EL panel characterized by having a structure that avoids transparent electrodes.