JPH11167989A - Film formation method and manufacture of display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of a yield resulting from the separation of a protection film in the formation of lead terminal electrodes on the lower portion electrode and the upper portion electrode of an EL (electroluminescence) by an electroless plating method. SOLUTION: A lower portion electrode 2 is formed on a glass substrate 1, and a lower portion insulating layer 3, an luminescence layer 4, an upper portion insulating layer 5, and an upper portion electrode 6 are formed thereon so as to constitute an EL element. In the forming process of the upper electrode 6, a dummy electrode 7 is formed using the same ITO electrode material as the upper portion electrode 6. Thereafter, an protection film is formed on the EL element, using the same as a mask lead terminal electrodes are formed at the end portions of the lower portion electrode 2 and the upper portion electrode 6 by an electroless plating method. In this case, the separation of the protection film is prevented at the plating time by the dummy electrode 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a film having a predetermined pattern on a glass substrate, and a method for manufacturing a display panel such as an EL (electroluminescence) display panel or a TFT liquid crystal display panel.

[0002]

2. Description of the Related Art Conventionally, in a display panel in which a display element such as a thin film EL element or a TFT liquid crystal display element is formed on a glass substrate, a lead terminal electrode is formed at an end of an electrode of the display element, and the lead terminal electrode is used. It is electrically connected to an external circuit. The lead terminal electrodes are metallized with a solderable metal. For example, a method of metallizing Ni (nickel) or Au (gold) by a sputtering method or a vacuum evaporation method can be used. However, this forming method has a problem that productivity is low since many manufacturing steps in vacuum are required.

[0003]

Therefore, the present inventors have studied a method of forming a lead terminal electrode by metallizing the electrode by electroless plating. In FIG.
The manufacturing process of the EL panel examined by the inventors is shown. First, an EL element is formed on a glass substrate 21. Specifically, a plurality of lower electrodes 22 parallel to each other are formed on a glass substrate 21, a lower insulating layer, a light emitting layer, and an upper insulating layer are formed thereon, and the lower electrode 22 is formed on the upper insulating layer. A plurality of upper electrodes 23 are formed so as to be orthogonal to. This state is shown in FIG.

Thereafter, a protective film 24 made of an organic material is selectively formed on the EL element except for the ends of the lower electrode 22 and the upper electrode 23 (see FIG. 8B). Next, a pre-plating process is performed, and palladium 2 is applied to the surfaces of the lower electrode 22 and the upper electrode 23 that are not covered with the protective film 24.
5 (see FIG. 8 (c)). Then, a Ni film is formed on the palladium 25 by performing a Ni plating process, and a displacement gold plating process is performed on the Ni film to form lead terminal electrodes 26 and 27 on the lower electrode 22 and the upper electrode 23, respectively. (See FIG. 8D). Finally, the protective film 24 is removed (see FIG. 8E).

When such a method is used, the glass substrate 21 is made of inorganic glass and its surface is hydrophobic, so that it has poor wettability and is flat, and its thermal expansion coefficient is much smaller than that of organic materials. In addition, the adhesion between the glass substrate 11 and the protective film 14 made of an organic substance is poor, and the protective film 14 is peeled off during the plating process (the process of performing a chemical treatment heated in an acid-alkali solution and a reducing solution). It turned out that there was a case.

When the peeled protective film 14 adheres to the electrode portion to be plated, as shown in FIG. 8 (d), unplated defects are generated and the yield is reduced. In particular, when the protective film 14 is applied by using a printing machine, the protective film 14 protrudes onto the glass substrate 11 so as to increase.
Yield reduction caused by peeling of the protective film is likely to occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to prevent a yield from being reduced by peeling of a protective film.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, an anti-peeling film (7) is formed on a glass substrate (1) in advance, and a protective film is formed thereon. It is characterized in that a film (8) is formed and a film is formed by plating. Therefore, by providing the peeling prevention film (7), it is possible to prevent the protection film (8) from peeling off during the plating process and to prevent a decrease in yield.

[0009] In the film formation by plating,
As in the invention described in (1), the method can be applied to the electrodes (2, 6) constituting the display elements (2 to 6). In this case, as in the invention according to claim 3, the peeling prevention film (7)
Are formed between the plurality of lower electrodes (2) and between the plurality of upper electrodes (6), the contact area between the glass substrate (1) and the protective film (8) is increased. Since it can be reduced, peeling of the protective film (8) can be effectively prevented.

Further, according to the present invention, the protective film (8) may be formed between the lower electrode (2) and the upper electrode (6). Can be effectively prevented. In particular, anti-peeling film (7)
Between the plurality of lower electrodes (2) and between the plurality of upper electrodes (6) and the lower electrode (2).
If the protective film (8) is formed between the glass substrate (1) and the protective film (8), the contact area between the glass substrate (1) and the protective film (8) can be extremely reduced. It can be done effectively.

According to a fifth aspect of the present invention, in the step of forming the upper electrode (6), the upper electrode (6) is formed.
If the peel prevention film (7) is formed as a dummy electrode using the same electrode material as described above, the formation of the peel prevention film (7) can be performed without increasing the number of steps. Further, as set forth in claim 6, the peel prevention film (7) is provided with a plurality of islands (7).
If it is formed in a subdivided shape in 1), the peeling prevention film (7)
Can be hardly recognized. In this case, an island (71) and an island (71) are provided as in the invention according to claim 7.
Is set to 0.2 mm or less, peeling can be reliably prevented. When the anti-peeling film (7) is a dummy electrode, the insulating property can be ensured by forming it into an island shape.

The above-mentioned reference numerals in parentheses indicate the correspondence with specific means described in the embodiment described later.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. 1 to 5 show a method for manufacturing an EL element panel according to one embodiment of the present invention. In each of the drawings, (a) is a plan view, and (b) is a cross-sectional view taken along line AA in (a). [Step of FIG. 1] An EL element is formed on a glass substrate 1.
Specifically, a plurality of lower electrodes 2 parallel to each other are formed on a glass substrate 1, and a lower insulating layer 3, a light emitting layer 4 and an upper insulating layer 5 are formed thereon. Then, a plurality of upper electrodes 6 are formed so as to be orthogonal to the lower electrode 2. The lower electrode 2 and the upper electrode 6 are transparent electrodes made of ITO.

In the step of forming the upper electrode 6, a dummy electrode 7 as an anti-peeling film is formed of the same electrode material of ITO as the upper electrode 6. The dummy electrode 7 is formed between each of the plurality of lower electrodes 2 and the upper electrode 6 and between the lower electrode 2 and the upper electrode 6 at the corners. The dummy electrode 7 made of ITO has good adhesion to the glass substrate 1 and a protective film 8 described later, and the provision of the dummy electrode 7 reduces the contact area between the protective film 8 and the glass substrate 1. Therefore, peeling of the protective film 8 can be prevented. [Step in FIG. 2] Thereafter, a protective film 14 made of an organic substance is selectively formed on the EL element except for a part (end) of the lower electrode 2 and the upper electrode 6 by a printing method (flexographic printing method). Formed. As this protective film 8, for example, a resist containing Ni plating catalyst poison (TLCRP8008 manufactured by Tokyo Ohka Kogyo Co., Ltd.) can be used. [Step in FIG. 3] Next, a plating pretreatment step is performed to deposit palladium 9 on the surface of the lower electrode 2 and the upper electrode 6 which are not covered with the protective film 8 (non-mask region). [Step of FIG. 4] Next, a Ni film is formed on the palladium 9 by performing a Ni plating process, and a displacement gold plating process is performed on the Ni film, and the lead terminal electrode 10 is formed on the lower electrode 2 and the upper electrode 6. , 11 are formed respectively. [Step of FIG. 5] Finally, the protective film 8 is removed by immersing it in, for example, N-methyl-2-pyrrolidone heated to 70 ° C. Thus, an EL panel is manufactured.

According to the above-described embodiment, the dummy electrode 7 as the peeling prevention film is arranged in advance on the outer peripheral portion of the area on the glass substrate 1 where the protection film 8 is to be covered.
The problem of peeling of the protective film 8 can be solved, and a decrease in yield can be prevented. Further, the dummy electrode 7 is formed in a shape subdivided into a plurality of islands 71 as shown in FIG. 6 in which a portion B in FIG. 1A is enlarged. By forming the dummy electrode 7 in a subdivided shape in this manner, insulation is ensured, and when the dummy electrode 7 is used as an EL display, the dummy electrode 7 is formed.
Can be hardly seen, and the floating electric capacitance can be further reduced.

FIG. 7 shows the relationship between the distance between islands and the separation of the protective film 8. From this figure, it is understood that the separation of the protective film 8 can be prevented by setting the distance between the islands to 0.2 mm or less. The peel prevention film may be any film having good adhesion to the glass substrate 1 and the protective film 8, and may be a transparent conductive film of indium oxide or tin oxide, tantalum oxide, silicon nitride, or silicon nitride oxide. A system insulating film can be used. Also,
As the protective film, an organic resin can be used, and any of a novolak resin, a urethane resin, and a phenol resin can be used instead.

The location where the dummy electrode 7 is formed is not limited to between the lower electrode 2 and the upper electrode 6 and between the lower electrode 2 and the upper electrode 6, but may be any one of them. Good. Further, as the EL element, in addition to the thin film EL element described above, a dispersion type EL element,
An organic EL element or the like can be used. In addition to the above-described EL panel, the present invention can be applied to a display panel such as a TFT liquid crystal display panel. In addition to the display panel, the present invention relates to various techniques for forming a protective film on a glass substrate and forming a film. Can be applied.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a manufacturing process of an EL panel according to an embodiment of the present invention.

FIG. 2 is a view showing a manufacturing process following FIG. 1;

FIG. 3 is a view showing a manufacturing process following FIG. 2;

FIG. 4 is a view showing a manufacturing step following FIG. 3;

FIG. 5 is a view showing a manufacturing step following FIG. 4;

FIG. 6 is an enlarged view of a dummy electrode 7;

FIG. 7 shows an interval between islands and a protective film 8 in a dummy electrode 7;
FIG. 4 is a diagram showing a relationship of peeling of the slab.

FIG. 8 is a diagram showing a manufacturing process of an EL panel studied by the present inventors before.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Lower electrode, 3 ... Lower insulating layer, 4 ...
Light emitting layer, 5: upper insulating layer, 6: upper electrode, 7: dummy electrode, 8: protective film, 9: palladium, 10, 11: lead terminal electrode.

Claims (7)

[Claims] 1. A protective film (8) is formed on a glass substrate (1), a film forming process is performed by plating using the protective film (8) as a mask, and thereafter, the protective film (8) is removed. hand,
On the glass substrate (1), a film (10, 1
A film forming method for forming 1), wherein a peeling preventing film (7) for preventing peeling of the protective film (8) is formed on the glass substrate (1), and the protective film (8) is formed.
Forming a film. 2. A display element (2-6) having electrodes (2, 6) extended on a glass substrate (1), and a protective film (8) on the display element (2-6). Is formed, and terminal electrodes (10, 11) are formed by plating using the protective film (8) as a mask in a non-masked region of the electrodes (2, 6). Thereafter, the protective film (8) is removed. A method for manufacturing a display panel, comprising: forming a separation preventing film (7) for preventing separation of the protective film (8) on the glass substrate (1); and forming the protective film (8).
Forming a display panel. 3. The electrode (2, 6) comprises a plurality of lower electrodes (2) and a plurality of upper electrodes (6) orthogonal to the lower electrodes (2). The peel prevention film (7) is formed between each of the plurality of lower electrodes (2) and between each of the plurality of upper electrodes (6). The method for manufacturing the display panel described in the above. 4. The method for manufacturing a display panel according to claim 2, wherein the peeling prevention film (7) is formed between the lower electrode (2) and the upper electrode (6). . 5. The method according to claim 2, wherein in the step of forming the upper electrode, the anti-peeling film is formed of the same electrode material as the upper electrode.
The method for manufacturing a display panel according to any one of the above. 6. The method according to claim 1, wherein said peeling prevention film is provided with a plurality of islands.
6. The method of manufacturing a display panel according to claim 2, wherein the display panel is formed in a shape subdivided into 1). 7. The method according to claim 6, wherein a distance between the islands (71) is set to 0.2 mm or less.