JPS6363086A - Dot matrix type display device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to unit pixels arranged in an IJ wax pattern, and each pixel includes a drive transistor for driving a display body, and a writing transistor for supplying a video signal for driving. A dot O matrix type display device having a transistor, the display device having a structure in which a display component is formed via a protective insulating film on a semiconductor substrate on which a display drive circuit including the drive transistor and write transistor is formed.・Ma) I
The present invention relates to a J-socks display device.

<Prior Art> FIG. 4 is a block diagram of a conventional dot matrix type display device having the above structure. In the figure, Gi j (
i=1. L-m,j=L L-,n) are each unit pixel arranged in a matrix, and each pixel is
It has a drive transistor Tl1j that drives the transistor Tl1j and a write transistor T2ij that supplies a video signal for driving. Note that Cij is a video signal storage capacitor. Further, Xi is a scanning signal supply line, and Yj is a video signal supply line.

A display drive circuit including the drive transistor, write transistor, etc. is formed on a single semiconductor substrate, and display components are formed on the conductor substrate with a protective insulating film interposed therebetween. Although only the pixel portion is shown in FIG. 4, it may also include peripheral circuits such as a scanning circuit.

For example, in the case of a dot matrix type fluorescent display device, as shown in FIG. and grid G.

The drive transistor of each pixel is turned on and off in response to a video signal, and the phosphor layer changes into a light-emitting or non-light-emitting state accordingly, thereby displaying a desired pattern in a dot matrix type display device such as the above. In this case, defects in pixels on the screen greatly affect display quality, and it is desired to reduce defects from the viewpoint of product yield. In particular, it is desirable that the white defect, which is always in a light-emitting state, be O.

One of the causes of this white defect is the 1 drive transistor T.
It is possible that l1j is defective, but there is a patent that has already been filed as a countermeasure (Japanese Patent Application No. 61-76339).

However, there are some failure modes that cannot be handled by such a circuit method.

As shown in FIG. 6, this occurs when the protective insulating film (PSG or the like) 9 underlying the phosphor layer Kij has defects such as holes or cracks (hereinafter referred to as "cracks"). In FIG. 6, due to the presence of the crack 10, the phosphor layer Ktj is short-circuited to the conductor (A77 or the like) 8 connected to the source 5 of the drive transistor Tl1j.

This results in white defects. In addition, in the figure, 1 is an St substrate, 2 is a gate insulating film, 3 is a gate of a driving transistor, 4 is a drain thereof, and 6 is an insulating film (S i 02
.

PSG, etc.), 7 is a conductor (Ae, etc.).

<Object of the Invention> The present invention has been made in view of the above-mentioned points, and provides a method that does not cause white defects even if there are cracks or the like. That is, the present invention prevents the occurrence of white defects due to cranks, etc. by changing the protective insulating film, which is a single layer film in conventional display devices, to a laminated film having an insulating film-conductive film-insulating film structure. A dot matrix type display device is provided.

<Example> Hereinafter, the present invention will be described in detail based on an example. FIG. 1 is a sectional view showing the structure of a dot matrix type fluorescent display device according to an example of the present invention.

In the figure, the same functional parts as in FIG. 6 are given the same numbers and detailed explanations will be omitted.

As shown in the figure, a laminated film having a structure of 11 insulating films (PSG, etc.), 12 metal films (AI!, etc.), -122 - 13 insulating films (PSG, SiN, etc.) is provided as the protective insulating film. The metal film is provided independently for each pixel. The pattern is shown in FIG. FIG. 2 is a plan layout diagram of one pixel section. In the figure, Pk is the pattern of the phosphor layer Kij, Plr Pz is the metal film 12t, respectively.
, 122 patterns. The phosphor layer Kij is a metal film 1
It is electrically connected to the conductor 7 via 2+. On the other hand, the metal film 122 is electrically floating. Therefore, even if there is a crack 14 in the insulating film 13 and the phosphor layer Kij and the metal film 122 are connected, it does not become a white defect as in the conventional device.

Further, according to this structure, the light-shielding property of the metal film prevents external light or light emitted from the phosphor layer from reaching the drive transistor and other transistors, thereby preventing malfunctions caused by light.

FIG. 3 shows the structure of an embodiment of the pond.

Metal film 121 + 122 or 1 in each of the above embodiments
2 may be replaced with another conductive film.

Although the above embodiment is an example in which the present invention is implemented in a dot matrix type fluorescent display device, the present invention is also effective in other dot matrix type display devices, such as EL display devices, liquid crystal display devices, etc. Needless to say, it is something that can be implemented.

<Effects of the Invention> As explained in detail above, according to the present invention, the occurrence of white defects can be prevented and the yield can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the structure of one embodiment of the present invention, FIG. 2 is a plan layout diagram showing the pattern of the metal film constituting the protective insulating film in the same embodiment, and FIG. 3 is a diagram showing another embodiment. A cross-sectional view showing the structure of an example, Fig. 4 is a block diagram of a dot matrix IJ hooks display device, Fig. 5 is a block diagram of one pixel part of a dot matrix type fluorescent display device, and Fig. 6 is a block diagram of a conventional dot matrix type fluorescent display device. -M) It is a sectional view showing the structure of an IJ Fuchs display device. Explanation of symbols 11: Insulating film, 12+, 122.12: Metal film,
13: Insulating film. Agent Patent Attorney Takeshi Sugiyama (and 1 other person) Figure 2 Figure 3 $4 Figure

Claims (1)

[Claims] 1. A dot matrix type display device in which unit pixels are arranged in a matrix, and each pixel has a drive transistor for driving a display body and a writing transistor for supplying a video signal for driving, the above-mentioned In a dot matrix display device in which a display element is formed via a protective insulating film on a semiconductor substrate on which a display driving circuit including a drive transistor and a write transistor is formed, as the protective insulating film. , insulation film-
A dot matrix type display device characterized by having a structure in which a laminated film having a conductive film-insulating film structure is provided.