JPH043015A - Formation of electrode of plzt optical shutter array - Google Patents

Abstract

PURPOSE:To easily obtain vertical type electrodes by adhering a PLZT substrate which is formed with land electrodes at prescribed intervals on one surface and a transparent substrate which is formed with bumps and wiring patterns by a transparent adhesive, then forming grooves of the depth arriving at the land electrodes, forming conductive films in these grooves and dividing the PLZT substrate. CONSTITUTION:The PLZT substrate 1 which is formed with the land electrodes at the prescribed intervals on the one surface and the transparent substrate 10 which is formed with the bumps 16 in the positions corresponding to the land electrode 12 and is formed with the wiring patterns 17 are adhered and fixed by the transparent adhesive 9 and thereafter, the grooves 13 of the depth arriving at the land electrodes 12 from the PLZT (PbO, LaO, ZrO2, TiO) substrate 1 are formed. The conductive films 11 are then formed in these grooves 13 and the grooves 14 perpendicular to the grooves 13 are formed. The PLZT substrate 1 is divided to a matrix shape to obtain independent picture elements. In addition, the conductive films 11 formed in the grooves 13 are used as the electrodes of the independent picture elements. The vertical electrodes are obtd. by the simple processes using the PLZT substrate 1 in this way, by which the degradation in the driving electrodes and the crosstalks are suppressed.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for forming electrodes of PLZT optical shutter arrays used in display devices such as flat displays and optical shutters by utilizing the birefringence of PLZT (transparent ceramic). More specifically, the present invention relates to a method for forming electrodes of a PLZT optical shutter array that effectively utilizes the driving voltage of each optical shutter.

[Conventional example] In recent years, transparent ceramic P made by adding La to PZT has been developed.
LZT (PbO, LaO, ZrO, Tie) is about to be used in optical shutters and displays. This P
When LZT is used in a display device such as a two-dimensional optical shutter or a flat display, the structures of surface electrodes and groove-shaped electrodes shown in FIGS. 7 to 10, for example, are adopted.

In the case of the surface electrode shown in FIG. 7, a drive electrode 2 and a common electrode (for example, GND) 3 are formed on a PLZT substrate 1,
By applying a voltage between these electrodes, an electric field is generated inside, and the light transmittance can be controlled by rotating the plane of polarization in that part. Furthermore, as shown in FIG. 8, in order to more effectively generate an electric field within the PLZT substrate 1, it is conceivable to form the drive electrode 2 and the common electrode 3 on both surfaces of the PLZT substrate 1.

On the other hand, in the case of the groove-type electrode shown in FIG. 9, when a voltage is applied between the g-movement electrode 4 and the common electrode 5, a more effective electric field can be generated than in the case of the surface electrode. A low F driving voltage can be expected. Furthermore, as shown in FIG. 1O, it is also conceivable to form drive electrodes 4 and common electrodes 5 from both sides of PLZT substrate 1 for the same purpose as the above-mentioned surface electrodes.

[Problems to be Solved by the Invention] However, the PLZT substrate with the above-mentioned surface electrode or groove-type electrode has the following drawbacks.

(1) Even though only the electric field component perpendicular to the light transmission direction contributes to transmittance control, the electric field generated within the PLZT substrate 1 as shown by the two-dot chain lines in FIGS. 7 to 10 is inevitably curved, so the voltage applied between these electrodes is not working effectively, making it difficult to further reduce the driving voltage.

(2) When a plurality of pixels are formed on the PLZT substrate 1, the electric field leaks to adjacent pixels, resulting in poor crosstalk.

(3) Since the PLZT substrate 1 has electrostrictive properties,
Strain occurs due to voltage application, and that strain is applied to the electrode (lli
, dynamic electrode, and common electrode), which not only causes deterioration of light transmittance but also causes damage such as cracks in the PLZT substrate 1 at these electrode portions.

(4) Light leakage occurs because the damage to the electrode portion extends to the adjacent pixel area.

(5) Due to the distortion caused by the applied voltage, various modes of vibration occur within the PLZT substrate 1, and in some cases vibration noise is generated.

In this invention, as shown in FIG. 11, if the drive electrode 6 and the common electrode 7 are independent vertical electrodes, each PLZT
The electric field generated at point 8 is perpendicular to the direction of the transmitted light (shown by the two-dot chain line in the figure), and the above (1) to (5)
This was done with a focus on eliminating the drawbacks shown in the following, and the purpose is to be able to fabricate vertical electrodes in a simple process using a PLZT substrate, and to reduce the drive electrode and improve crosstalk. It is an object of the present invention to provide a method for forming electrodes of a PLZT optical shutter array, which enables the formation of electrodes in a PLZT optical shutter array.

[Means for Solving the Problems] In order to achieve the above object, a method for forming electrodes for a PLZT optical shutter array according to the present invention includes forming land electrodes at predetermined intervals on one side of a PLZT substrate. Z
A bump is formed on the transparent substrate to be adhered to the T substrate at a position facing the land electrode, and a wiring pattern is formed to lead out the land electrode to the outside via the hump. After adhesively fixing the substrate and the transparent substrate with a transparent adhesive, a groove having a depth reaching at least the land electrode is formed on the PLZT substrate, and a conductive film is formed in the groove. The gist of this invention is to form perpendicular grooves and divide the Hokkaido PLZT substrate into matrix shapes to obtain independent pixels, and to use the conductive film formed in the grooves as electrodes of the independent pixels.

Further, in the method for forming electrodes of a PLZT optical shutter array of the present invention, land electrodes are formed on one surface of a PLZT substrate at predetermined intervals, and the above-described transparent substrate is bonded to the PLZT substrate with a transparent adhesive. A bump is formed at a position facing the land electrode, and a wiring pattern is formed to lead the land electrode to the outside via this bump, and the PLZT substrate and the transparent substrate are adhesively fixed with a transparent adhesive. After that, a lift-off resin is applied to the bonded PLZT substrate, and a first groove is deep enough to reach at least the land electrode from the hill of the lift-off resin, and the groove is deeper than the first groove.

A parallel second groove is formed, and then the lift-off resin application surface and the first groove are formed. A conductive film is formed across the inside of the second groove, and then the lift-off resin is peeled off. A third groove of intermediate depth is formed to make the PLZT substrate into a plurality of independent 1M elements, and the metal film remaining in the first and second grooves is used as the electrode of the independent pixel. .

[Function] Since the above method is used, the PLZT substrate is divided into multiple pieces,
A plurality of independent pixels are obtained, and both ends of these pixels become vertical electrodes due to the metal films formed in the first and second grooves. In addition, the metal film formed in the first groove is connected to the land electrode, and the land electrode is connected to the wiring pattern via the bump, so the electrode of each independent pixel is connected to the outside via the wiring pattern. It can be pulled out. Furthermore, when driving each individual pixel, the electric field generated inside becomes linear because the electrodes of these independent pixels are vertical.
The voltage applied between the electrodes of each q pixel can be lowered, and leakage of distortion, etc. to crosstalk between adjacent pixels can be prevented.

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 to 6.

1 and 2 show a schematic partial cross-sectional view and a front view of a PLZT optical shutter array obtained by the electrode forming method of the present invention.
Each pixel 8a (same as in Figure 0) 1 is independently adhesively fixed to a transparent substrate (for example, a glass plate) 10 using a transparent adhesive 9.

Each pixel 8a is deeper than the first groove 13 and the first groove 1114 in which the metal film (conductive film) 11 connected to the land electrode 12 is formed, at least to reach the adhesive 9;
A second groove 1 in which a metal film (conductive film 01) is formed on the inside in parallel.
4 and the first and second grooves 13 and 14, and are divided into a matrix by a third groove (dividing groove; shown by the two-dot chain line in FIG. 1) 15 at an intermediate depth. There is. Each pixel 8a of 5 cells q has an electrode (drive electrode) formed by the metal film 11 formed in the first groove 13 and a second groove 14.
It has an electrode (common electrode) made of a metal film 11 formed on the substrate, and these electrodes are vertical.

On the other hand, the glass plate 10 bonded to the PLZT substrate 1 has a bump 16 formed of metal, ITO (Induim Tin Oxide), etc. at a position facing the land electrode 12 connected to the metal film 11 formed in the first groove I3. It has a wiring pattern (signal line) 17 that leads the drive electrode to the outside through the bump 16, and when bonded together, the land electrode 12 and the bump 16 are connected, and the land electrode 12 and the bump 16 are connected to each other. The metal film 11 connected to the electrode 12 can be drawn out. In this case, each pixel 8a of various types to γ has a three-pole electrode structure formed by the metal film 11 formed in the first and second grooves 13, 1.4.

Next, to explain the manufacturing process of an independent pixel 8a using the metal film 11 formed in the first and second grooves 13 and 14 of the letter L as electrodes, first, as shown in FIG. Forming land electrodes 12 at predetermined intervals on one surface of 1,
Further, a lift-off resin such as a polymer film 18 such as a resist is applied to the other surface. On the other hand, a bump L6 is formed on the glass plate IO to be adhered to the surface on which the land electrode 12 is formed, at a position facing the runt electrode 12, and a wiring pattern 17 is formed to draw out the land electrode I2 to the outside.

Thereafter, as shown in FIG. 4, the ZT substrate J and the glass plate IO are bonded and fixed using an adhesive 9.

The adhesive 9 may be transparent and flexible even after curing to absorb vibrations of the PLZT substrate 1, preferably silicone rubber. Further, the thickness of the adhesive 9 is set to such a level that it can sufficiently absorb the vibrations, and that no extra stress is applied to the PLZT substrate 1 when it is cured. Note that the polymer film 18 may be formed after the PLZT substrate 1 and the glass plate 10 are bonded and fixed.

Subsequently, as shown in FIG. 4, a plurality of first grooves 13 are formed in parallel from above the applied polymer film 18, reaching at least the adhesive 9 and reaching the land electrode 12. Form. Furthermore, a plurality of second grooves 14 which are parallel to and deeper than the first grooves 13 are formed using the same dicing saw. Note that the interval between the first and second grooves 13 and 14 may be changed depending on the size of the pixel 8a.

Subsequently, as shown in FIGS. 5 and 6, the surface of the polymer film 18 and the first and second grooves 13.1 are
A metal film 11 is formed by sputtering over the inside of 4.
Deposit a film. Thereafter, as shown in FIGS. 6 and 9, when the polymer film 18 coated on the PLZT substrate 1 is removed using a stripping solution, the metal film 11 formed on the polymer film 18 is removed. Since the metal film 11 is removed, only the inner surfaces of the first and second grooves 13 are left.

Subsequently, as shown at two points am in FIG. 6, a dicing saw is used to cut the first groove 13 deeper than the second groove 4 and shallower than the second groove 4, that is, perpendicular to them at an intermediate depth. A plurality of third grooves 15 are formed in parallel. Then,
Since the PLZT substrate 1 is divided into a matrix,
Each independent pixel 8a can be obtained, and each independent pixel p8a is provided with a vertical electrode made of the metal film 11 formed in the first and second grooves 13,14. Therefore, as shown in FIGS. 1 and 2, PLZ
The T-substrate 1 is a two-dimensional array of independent pixels 8a having vertical electrodes.

In this way, the independent PLZT pixels 8a are arranged two-dimensionally through normal processes such as cutting with a dicing saw, forming a metal film by sputtering method and lift-off method,
Also, the electrodes (drive electrode and common electrode) of those pixels 8a
By making the PLZT vertical, the strain generated within the PLZT can be made uniform and damage can be prevented, and the electric field generated between the electrodes can be made perpendicular to the direction of light transmission. , the applied voltage can be used effectively, and the drive voltage can be further reduced. moreover.

Since each pixel 8a is independent, the adjacent pixel Ji48a
This eliminates leakage of the electric field to and improves crosstalk.

[Effects of the Invention] As explained above, according to the method for forming electrodes of a PLZT optical shutter array of the present invention, land electrodes are formed on one side of a PLZT substrate at predetermined intervals, and transparent A bump is formed on the substrate at a position facing the land electrode.

A wiring pattern is formed to lead out the land electrode to the outside through this bump, and after bonding and fixing the PLZT substrate and the transparent substrate with a transparent adhesive, the PLZT
A groove with a depth reaching at least the land electrode is formed on the ZT substrate, a conductive film is formed in the groove, and then a groove is formed at right angles to the groove, and the PLZT substrate is divided into a matrix. Since each independent pixel was obtained by using the method, and the conductive film formed in the groove was used as the electrode of each independent pixel, the electrode of each pixel became vertical, so it was possible to reduce the driving voltage applied between the electrodes. Moreover, since crosstalk to adjacent pixels can be improved, it is possible to realize a PLZT optical shutter array as a display device such as a flat display or an optical shutter.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 show an embodiment of the present invention, and P
A schematic side sectional view and a front view of a circle-ZT optical shutter array to which the electrode formation method of the LZT optical shutter array is applied, and FIGS. 3 to 6 are diagrams for explaining the electrode formation method of the PLZT optical shutter array. Process diagram, Figures 7 to 1
Figure O is a diagram for explaining the surface electrode and groove-type electrode of the PLZT optical shutter array, and FIG. 11 is a diagram for explaining the vertical electrode of the PLZT optical shutter array. In the figure, ■ is a PLZT substrate, 8a is a pixel, 9 is an adhesive (transparent), IO is a transparent substrate (glass plate), and 11 is a conductive film (
12 is a land electrode, 13 is a first groove (drive electrode), 14 is a second groove (common electrode), 15 is a third groove (
dividing groove). 16 is a bump. 17 is a wiring pattern (including electrodes). 18 is a polymer film (such as a lift-off resist film).

Claims (2)

[Claims] (1) Land electrodes are formed on one side of the PLZT substrate at predetermined intervals, and bumps are formed on the transparent substrate to be adhered to the PLZT substrate at positions facing the land electrodes, and the A wiring pattern is formed to lead the land electrode to the outside, and after the PLZT substrate and the transparent substrate are adhesively fixed with a transparent adhesive, a groove with a depth reaching at least the land electrode is formed on the PLZT substrate. After forming the PLZT substrate, a conductive film is formed in the groove, a groove is formed at right angles to the groove, the PLZT substrate is divided into a matrix shape to obtain independent pixels, and the conductive film formed in the groove is A method of forming an electrode of a PLZT optical shutter array, characterized in that the electrode is used as an electrode of the independent pixel. (2) Land electrodes are formed on one surface of the PLZT substrate at predetermined intervals, and bumps are formed on the transparent substrate that is bonded to the PLZT substrate with a transparent adhesive at positions opposite to the land electrodes. , a wiring pattern is formed to lead the land electrode to the outside through the bump, and after the PLZT substrate and the transparent substrate are adhesively fixed with a transparent adhesive, a lift-off is possible to the bonded PLZT substrate. While applying the resin, a first groove having a depth reaching at least the land electrode and a second groove deeper and parallel to the first groove are formed on the resin that can be lifted off, and then the A conductive film is formed over the coated surface of the lift-off resin and within the first and second grooves, and then the lift-off resin is peeled off, and the conductive film is perpendicular to the first and second grooves, and A third groove having a depth intermediate between the first groove and the second groove is formed, the PLZT substrate is made into a plurality of independent pixels, and the metal film remaining in the first and second grooves is removed. A method of forming an electrode of a PLZT optical shutter array, characterized in that the electrode is used as an electrode of the independent pixel.