JPH0778580B2 - Method for manufacturing electrode in PLZT display device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing an electrode in a PLZT display device using the birefringence of PLZT (transparent ceramic), and more particularly to a groove type and a comb type. The present invention relates to a method of manufacturing electrodes in a PLZT display device, which makes it possible to realize a fine optical shutter array or a flat display when forming a mold drive electrode and a common electrode.

[Conventional example] In recent years, PLZT (Pb
O, LaO, ZrO ₂ , TiO) are about to be used for optical shutters and displays. When this PLZT is used as an optical shutter array or a flat display, for example, the surface electrode shown in FIG. 7 or the groove type electrode shown in FIG. 8 is adopted. In FIG. 7, the drive electrode 2 and the common electrode (GND) 3 are formed on the PLZT substrate 1 by the sputtering method or the like. Further, in FIG. 8, the PLZT substrate 1 is filled with electrodes in grooves formed by machining or etching.
A drive electrode 4 and a common electrode (GND) 5 are formed.

This groove-type electrode structure has a PLZT
Since the electric field distribution in the substrate 1 becomes good, there is an advantage that the driving voltage can be lowered. Further, the narrower the width of the groove-shaped drive electrode 4 and the common electrode 5, the higher the aperture ratio. Therefore, when forming the groove-type electrode, it is more effective to use a machining process such as a dicing cutter that can cut a groove that is deeper and narrower than etching. That is, in the above etching, a complicated pattern can be formed, but since it is side etching,
This is because when the groove is deepened, the width of the groove also becomes wide.

[Problems to be Solved by the Invention] However, in the mechanical processing of the dicing cutter and the like, it is unsuitable for fine processing (for example, processing of a short groove) and curved processing, and therefore, a groove type electrode for a minute optical shutter is used. It was difficult to form the groove.

Further, when forming the above-mentioned groove type electrode, it is necessary to form a metal film in the groove formed by machining or etching and perform patterning by a photolithography process, but as the groove becomes deeper and narrower, the patterning becomes more difficult. Becomes difficult. That is, as shown in FIG. 9, in the resist coating in the photolithography process, the resist film 7 is formed in the groove 6.
However, as shown in FIG. 10, as shown in FIG.
The resist film 7 is not uniform and uneven. Moreover, when a positive type resist film 7 is used, pattern breakage may occur at the edge 6a of the groove 6 during patterning. Furthermore, as shown in FIG. 11, if the resist film 7 is too thick, the patterning of the bottom 6b of the groove cannot be cut (the cutting inside the groove 6 cannot be done), and the groove-type electrode may not be formed. is there. As a result, the wiring cannot be pulled out from the groove 6,
It has been an obstacle to the realization of fine optical shutter arrays and flat displays.

The present invention has been made in view of the above problems, and an object thereof is to eliminate a disconnection of a wiring pattern and obtain a groove type electrode capable of obtaining a fine optical shutter array or a display panel in a PLZT display device. It is to provide a manufacturing method of an electrode.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a first step of forming a plurality of grooves that are parallel to each other on a PLZT wafer at a predetermined interval, and it is difficult to form a groove in each groove. A solder metal film is formed, and the same hard solder metal film has irregularities corresponding to the above grooves on the PLZT wafer in a 1: 1 relationship, and the solder resistance in each groove is low. A second step of forming first and second patterns electrically connected to the metal film such that the concave portions and the convex portions face each other; and the hardly solderable metal of the first and second patterns. A third step of forming a solderable metal film on the film, and a tip portion of each convex portion of the first and second patterns along the direction orthogonal to the groove, and inside the groove between the convex portions. A continuous cutting groove deeper than the above groove is formed so as to separate the difficult-to-solder metal film. And a fifth step of electrically connecting the tip end portion of the convex portion and the base portion side of the convex portion, which are separated by the cutting groove, of the first and second patterns. One of them is a common electrode and the other is a drive electrode.

[Operation] With the above configuration, every other independent groove-type electrode is alternately connected to the convex portions of the first and second patterns, and by this connection, the groove-shaped and comb-shaped electrodes are formed. A common electrode and a drive electrode are formed. In addition, these electrodes are formed so as to enter between the combs of the counterpart electrodes.

Therefore, a plurality of optical shutters can be formed by forming a groove-type electrode having a plurality of grooves on the PLZT wafer and forming a plurality of second patterns for the first pattern. Moreover, since the optical shutter is formed by the groove-shaped and comb-shaped electrodes, a fine optical shutter array or display panel is obtained, and the aperture ratio of the optical shutter is increased and the driving voltage is lowered. be able to.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

In FIG. 1, on a PLZT wafer 1 as a PLZT display device, grooves are cut at predetermined intervals by mechanical processing such as a dicing cutter, a metal film is formed in these grooves, and a groove type electrode 8 is formed. A first portion having a shape of a concave portion 9a and a convex portion 9b in the direction perpendicular to the groove type electrodes 8 and on the side.
Of the concave portion 1 facing the pattern 9 and the convex portion 9b and the concave portion 9a thereof.
A metal film is formed on the second pattern 10 having the shape of 0a and the convex portion 10b to form an electrode portion. Further, each groove-type electrode 8 is cut by a groove cut across each convex portion 9b and each convex portion 10b along a direction orthogonal to the groove-shaped electrode 8.
Thereby, the convex portions 9b, 1 of the first and second patterns 9,10 are formed.
Since every other groove-shaped electrode 8 is assigned to the metal film of 0b, a comb-shaped electrode is formed by the groove-shaped electrode 8 and the electrode portions formed by the first and second patterns 9 and 10. That is, as shown by the broken line in the figure, if the comb-shaped and groove-shaped electrodes are used as the common electrode and the drive electrode, one optical shutter 11 is formed.

Next, a manufacturing process of the groove-shaped and comb-shaped electrodes in the PLZT display device will be described with reference to FIGS. 2 to 6.

First, as shown in FIG. 2, grooves 6 are cut on the PLZT wafer 1 at predetermined intervals by machining. In this case, if a dicing cutter or the like is used, the groove 6 having a width of 30 μm to 40 μm can be cut up to a depth of 150 μm.

Then, as shown in FIG. 3, on the PLZT wafer 1, a difficult-to-solder metal (for example, NiCr) is formed by the sputtering method, and the inside of the groove 6 and the PLZT wafer are formed by a normal photolithography process. A predetermined pattern (the first and second patterns 9 and 10) is patterned on a part of the surface of the wafer 1. At this time, the positive type resist has the film thickness distribution shown in FIG. 11, that is, the first and second patterns 9 and 10 on the PLZT wafer 1 are patterned by patterning.
The resist coating is performed thickly so that the metal film (electrode portion) and the metal film in the groove 6 (groove type electrode) are reliably connected. That is, it is not necessary to cut the pattern inside the groove 6. Then, a solderable metal (for example, Au) is formed on the PLZT wafer 1, and the solderable metal is overlaid on the first and second patterns 9 and 10 of the NiCr film by a normal photolithography process. The same pattern of the film (Au film) is formed. At this time, the Au film formation may be performed only on the NiCr films of the first and second patterns 9 and 10 formed on the surface of the PLZT wafer 1, and it is not necessary to form the inside of the groove 6,
The resist is thinly applied so that the positive type resist has the film thickness distribution shown in FIG. 10, that is, the Au film is formed only on the first and second patterns 9 and 10 by patterning.

Then, as shown in FIG. 4, a groove 12 deeper than the groove is cut in a direction perpendicular to the groove electrode 8 by a dicing cutter to form an independent groove electrode 8. That is, as shown in FIG. 5, the groove 12 cuts the tips of the convex portions 9b and 10b of the first and second patterns 9 and 10, and the first and second patterns thereof are cut. 9,
This is because the groove electrode 8 is cut near the other side of the groove 10.

After forming the groove 12, as shown in FIG.
The PLZT wafer 1 is subjected to solder dipping or solder flow, and only the tips of the cut convex portions 9b and 10b of the first and second patterns 9 and 10 cross the groove 12 and are connected to their base side. Is the portion indicated by the arrow A in FIG.
The parts that are only disconnected are not connected. That is,
This is because the width of the groove 12 is as narrow as 40 μm at the most, and the cut portions of the convex portions 9b and 10b are easily dip by solder,
Moreover, not the Au film but the NiCr film is formed in the groove 6,
This is because the solder is repelled, and the solder film is not formed on the portion indicated by the arrow A. Then, the groove-shaped electrodes 8 are independent of each other, and every other groove-shaped electrode 8 is alternately connected to the first and second patterns 9 and 10 via the convex portions 9b and 10b. Each is a groove-shaped and comb-shaped electrode.

Therefore, as shown in FIGS. 2 to 6, the first
The second pattern 10 is plural for the pattern 9 of
The first pattern 9 is used as a common electrode (CND), and
If the second pattern 10 is used as a drive electrode, a plurality of optical shutters 11 surrounded by a broken line in FIG. 6 can be formed, and the common electrodes and drive electrodes of the plurality of optical shutters 11 are groove type. And it can be comb-shaped. As a result, the aperture ratio of the shutter can be increased and the drive voltage can be reduced, and a fine optical shutter array or display panel can be realized.

[Effects of the Invention] As described above, according to the present invention, a plurality of grooves that are parallel to each other are formed on a PLZT wafer at a predetermined interval, and a difficult-to-solder metal film is formed in each groove. ,
On the PLZT wafer with the same difficult-to-solder metal film, there are irregularities corresponding to the above-mentioned grooves in a 1: 1 relationship, and there is electrical conduction with the difficult-to-solder metal film in each groove. After forming the first and second patterns so that the concave portions and the convex portions thereof face each other, a solderable metal film is formed on the hardly solderable metal film of the first and second patterns, Then, a deeper cut than the groove is cut along the direction orthogonal to the groove so as to separate the tip of each convex portion of the first and second patterns and the solder-resistant metal film in the groove between the convex portions. A groove is continuously formed, and thereafter, the tip end of the convex portion and the base side of the convex portion, which are separated by the cutting groove, are electrically connected to each other to form one of the first and second patterns. By using one of them as a common electrode and the other as a drive electrode, a normal dicing cutter and And photolithography technology, it is possible to form an optical shutter with a small aperture but a large aperture ratio, and it is possible to obtain a groove-shaped and comb-shaped electrode for a PLZT display device that requires a low driving voltage. The effect is played.

[Brief description of drawings]

FIG. 1 is a schematic front view of an electrode structure of a PLZT display device showing an embodiment of the present invention, FIGS. 2 to 6 are views for explaining a process of manufacturing electrodes of the PLZT display device, and FIG. 8 and 9 are schematic cross-sectional views for explaining the structures of conventional surface electrodes and groove-type electrodes, and FIGS. 9 to 11 are views for explaining a part of the conventional groove-type electrode manufacturing process. Is. In the figure, 1 is a PLZT wafer, 6 and 12 are grooves, 8 is a groove type electrode, 9 is a first pattern, 9a is a concave portion (of the first pattern), 9b is a convex portion (of the first pattern 9). , 10 is the second pattern, 10
Reference numeral a is a concave portion (of the second pattern), 10b is a convex portion (of the second pattern 10), and 11 is an optical shutter.

Claims (1)

[Claims] 1. A first step of forming a plurality of grooves on a PLZT wafer that are parallel to each other with a predetermined interval, and a difficult-to-solder metal film is formed in each of the grooves, and the difficult-to-solder metal film is formed. In the PLZT wafer, there are first and second patterns which have irregularities corresponding to the above-mentioned grooves in a 1: 1 relationship and which are electrically connected to the hard-to-solder metal film in each groove. And a third step of forming a solderable metal film on the hard-to-solder metal film of the first and second patterns. And deeper than the groove so as to separate the tip of each convex portion of the first and second patterns and the difficult-to-solder metal film in the groove between the convex portions along a direction orthogonal to the groove. A fourth step of continuously forming the cutting groove and the tip of the convex portion separated by the cutting groove A fifth step of electrically connecting the convex side to the base side, and one of the first and second patterns is a common electrode and the other is a drive electrode. PLZT display device electrode manufacturing method.