JPH02239591A - Thin film el element - Google Patents

Abstract

PURPOSE:To improve the adhesive property of an electrode terminal to a base by forming an insulating layer on a porous layer eroded by an etching solution, and providing the electrode terminal through an insulating layer. CONSTITUTION:An ITO film on a base 1 is processed into a stripe form by a photo-etching to form a transparent electrode 2. Then, on the transparent electrode 2, the first insulating film 3 is formed by a spattering. In this case, an insulating film same as the first insulating film is formed on a layer A, and also to a part to form a terminal electrode in a latter process. On the first insulating film 3, a luminous layer 4, the second insulating film 5, and a back electrode 7 are laminated. And, at the same time, on the second insulating film 3 formed at the end surface of the transparent electrode 2 and on the layer A, is formed a terminal electrode 6 which consists of luminous layers 6A and 6B same as the above laminated layer. By such a constitution, the adhesive property of the terminal electrode 6 and the base 1 can be improved.

Description

[Detailed Description of the Invention] Industrial Application Fields The present invention is... O.A. The present invention relates to thin film EL elements used as display devices in FA equipment and the like.

Conventional technology A perspective view of a conventional thin film EL element is shown in FIG.

In the figure, the material of the glass substrate 1 is non-alkali aluminosilicate glass (HOYA Glass' NA
-40, etc.) or porosilicate glass. On the glass substrate 1 (hereinafter simply referred to as a substrate), an ITO film is formed as a transparent electrode film by sputtering, and processed into a stripe shape by photo-etching to form a transparent electrode 2.

Next, a first insulating film 3, a light-emitting layer 4, and a second insulating film 5 are sequentially formed on the surface including the transparent electrode 2 by vapor deposition, sputtering, etc., and furthermore, a back electrode 6 is formed on the first insulating film 3, a light emitting layer 4, and a second insulating film 5, respectively. and Ni stacked films 7A, 7B and 6A, 6
B is formed by vapor deposition and processed into stripes by photo-etching.

In forming the terminal electrode 6, the corresponding portion of the transparent electrode 2 is removed by photo-etching so that the terminal electrode 6 can be directly formed on the substrate 1.

This is because the adhesion between the terminal electrode 6 and the transparent electrode 2 is poor (if the entire terminal electrode 6 is formed on the transparent electrode 2, the terminal electrode 6 will easily peel off during soldering etc.). Therefore, the terminal electrode 6 was formed on the substrate 1 to ensure adhesion.

Problems to be Solved by the Invention> However, in the above structure, the transparent electrode 2 in FIG.
Although the terminal electrode 6 connected to the end surface of the transparent electrode 2 is formed on the substrate 1 instead of on the transparent electrode 2,
Note that sufficient adhesion between the terminal electrode 6 and the substrate 1 cannot be obtained, and therefore, when connecting the terminal electrode 6 and an external drive circuit by soldering, a film is formed between the substrate I and the terminal electrode 6. There was a problem that peeling occurred. This problem will be explained in detail with reference to FIG.

FIG. 3 shows a cross-sectional view of a conventional thin film EL device.

In the figure, when a porosilicate glass, especially a porosilicate glass containing 10 wt% or more of B-Os, is used as the material of the substrate 1, {when forming the TO film on the transparent electrode 2 by photo-etching, the transparent electrode The surface of the substrate 1 near the terminal portion of No. 2 is attacked by the etching solution (a porous layer A containing a large amount of acid (HsSiOs) is formed. The reason for the formation of the layer A is that hydrochloric acid and This is because the B203 component of the substrate I is eluted by an etching solution containing hydrochloric acid such as a mixed solution of diiron.Since the layer A is a porous layer containing a lot of cinnamate acid (HsS i Os ), the electrode end The adhesion between the layer A and the surface of the board I becomes poor.For this reason, as mentioned above, when soldering, the layer A
There was a problem in that film peeling still occurred on the surface.

An object of the present invention is to solve the above problem of film peeling and to provide a highly reliable thin film EL element.

Means for Solving the Problems> In order to achieve the above object, the present invention has a structure in which an insulating layer is formed on a porous layer eroded by an etching solution, and an electrode terminal is provided through the insulating layer. did.

Effects> The above structure further improves the adhesion of the tW terminal to the substrate and improves the reliability of the thin film EL element.

Embodiment> A dormitory embodiment of the present invention will be described with reference to FIGS. 1(a) to (e). First, an ITO film with a thickness of 1000 to 3000 Å is formed by sputtering using an ITO target on a porosilicate glass (for example, Corning 7059, etc.) substrate l containing 10 wt% or more of B203 (see Fig.
a)). Next, it is processed into stripes by photo-etching to form transparent electrodes 2 (see FIG. 1, etc.). A mixed solution of hydrochloric acid and ferric chloride solution is used as the etching solution.

Next, Sift and SisNi are deposited as a first insulating film 8 on the transparent electrode 2 by sputtering, each having a thickness of 200 to 80%.
0A, 1000-8000A is formed. At this time. The same insulating film as above is applied on layer A and the terminal voltage vIi in a later process.
6 is also formed as shown in FIG. 3' (FIG. 1(C)). [Above No.] On top of insulation 8, zn
3: A light-emitting layer 4 made of Mn is formed with a thickness of 6000 to 8000 Å by electron beam evaporation, and vacuum annealed at 550 to 600°C.

Further, on the light emitting layer 4, a second insulating film 5 of Sf3 is formed.
A laminated film of N4 and Altos is formed by sputtering with a thickness of 1000-2000A% and 200-800A (Fig. 1(d)). Next, laminated films 7A and 7B using A/ and Ni, respectively, are formed on the second insulating film 5 as the back t-pole 7.
is formed by vapor deposition and photoetching. AI!
and Ni film thicknesses are both 2000 to 4000A. At the same time, a laminated film 6A, which is the same as the laminated film described above, is placed on the end face of the transparent electrode 2 and on the second insulating film 8' formed on the layer A.
, 6B is formed.

In addition, in the explanation of the above example, the terminal electrode 6 and the substrate 1 are
Although the improvement in adhesion between the back electrode 7 and the substrate l has been described, as is clear from FIG.

That is, in the step of FIG. 1(c), the first insulating layer 3I is extended not only to the connecting portion of the terminal electrode 6 but also to the electrode terminal of the back electrode 7 formed in the step of FIG. 1(e). , the adhesion between the back electrode 7 and the substrate l can be improved.

Further, as the insulating film formed on the A layer, in the above embodiment, the first insulating film 3 was used as the first insulating film 3', but instead, the second insulating film 5 or the first insulating film 3 and the second insulating film 3 were used. The same effect can be obtained even if both of the insulating films 5 are used.

Effects of the Invention> As described above, according to the present invention, it is possible to improve the adhesion of the electrode terminal to the substrate, and a highly reliable thin film EL element can be realized.

[Brief explanation of drawings]

Figures 1 to (e) are sectional views of essential parts at each step for explaining an embodiment of the present invention, Figure 2 is a perspective view of a conventional example, and Figure 3 is a sectional view of essential parts of a conventional example. It is. l...Glass substrate, 2...Transparent electric coffin, a, a'...
・No.! Insulating film, 4... Light emitting layer, 5... Second insulating film,
6...Terminal electrode, 7...Back electrode. Agent Patent attorney Takeshi Sugiyama (and 1 other person) Figure 1

Claims (1)

[Claims] 1. In a thin film EL device using porosilicate glass as a glass substrate, an insulating layer is formed on the surface of the glass substrate corresponding to the electrode terminal portion for connection to an external drive circuit, and the electrode terminal is provided through the insulating layer. Characteristic thin film EL element.