JPH01123215A - Production of optical shutter - Google Patents

Abstract

PURPOSE:To easily produce the title shutter and to eliminate problems such as contamination by a resist film by providing the heat-resistant resist film having the etching characteristic different from the etching characteristic of an electrode material so as to cover a shutter part region. CONSTITUTION:The heat-resistant resist film having the etching characteristic different from the etching characteristic of the electrode material is provided to cover the shutter part region on at least one face of a plate body 1 constituted of a material having an electro-optic effect. After grooves for electrodes are provided to said film, a metallic film 7 for the electrodes is formed thereon and the resist film is removed from the shutter part by etching to open the shutter part. The optical shutter is thus easily produced without deteriorating the properties of the resist film at the time of providing the metallic film for the electrodes by reverse sputtering or sputtering if the shutter part region is coated with the heat-resistant resist film having the etching characteristic different from the etching characteristic of the electrode material.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of manufacturing an optical shutter using a plate-shaped body made of a material having an electro-optic effect such as PLZT. It is something.

[Prior art and its problems] Conventionally, as a method for manufacturing an optical shutter using a plate-shaped body made of a material having an electro-optic effect such as PLZT, there is a method disclosed in Japanese Patent Laid-Open No. 61-38927. As shown in the figure, a photoresist is coated on the surface of a plate-shaped body having an electro-optical effect, exposed and developed, grooves are cut in this, a metal thin film for electrodes is deposited on top of the photoresist, and the metal thin film is deposited by lift-off. A known method is to remove a portion of the groove, open the shutter, and separate the thin metal film on the surface of the plate-shaped body, and then remove a portion of the thin metal film in the groove using a laser or the like to provide an independent electrode. It is being

However, it is extremely troublesome to form a pattern using photoresist on the surface of a plate-shaped body that has an electro-optic effect, or to remove a part of the metal thin film in the groove using a laser or the like. There were problems such as the time required for manufacturing.

In addition, in order to strongly adhere the metal thin film for electrodes to the surface of the plate-shaped body so as not to peel off, the surface of the plate-shaped body is cleaned by reverse sputtering, and then the metal thin film for electrodes is applied to the surface by sputtering. It is known that it is effective to attach

However, when these treatments are performed on the surface of a plate-shaped body provided with photoresist as described above, the photoresist changes in quality, causing contamination of the metal thin film for electrodes, and the adhesion of the metal thin film for electrodes. There are problems such as a decrease in strength, and in addition, various problems such as this contaminant intervening between the shutter and the electrode and having an adverse effect when applying voltage from the electrode to the shutter occur.

Furthermore, due to the deterioration of the photoresist, it becomes difficult to remove the photoresist by etching, which causes problems such as difficulty in opening the shutter properly.

[Purpose of the Invention] This invention was made to solve the above-mentioned problems, and it is possible to easily manufacture an optical shutter, and also to provide an optical shutter on the surface of a plate made of a material having an electro-optical effect. ,
Even when a thin metal film for electrodes is attached using a reverse sputtering or sputtering method, there is no problem such as contamination due to resist film, and the thin metal film for electrodes is firmly attached to the surface of the plate-shaped body. The object of the present invention is to provide a method for manufacturing an optical shutter that can be manufactured using the following methods.

[Means for Solving the Problems] In the method for manufacturing an optical shutter according to the present invention, at least one side of a plate-shaped body made of a material having an electro-optic effect is made of a heat-resistant etching material having different etching characteristics from the electrode material. A resist film is provided to cover at least the shutter region, a groove for the electrode is formed, a metal film for the electrode is formed thereon, and the resist film is removed from the shutter region by etching to open the shutter region. I decided to let them do it.

Here, as the heat-resistant resist film having different etching characteristics from the electrode material, a synthetic resin film such as polyimide resin can be used in addition to a metal film such as chromium or molybdenum or an inorganic dielectric film.

The important thing is that this resist film does not change in quality due to heat effects during reverse sputtering or sputtering.
Further, when the resist film is removed from the shutter portion by etching, it is sufficient that the electrode material provided in other parts is not removed together with the resist film.

[Function] When manufacturing an optical shutter using a plate-shaped body made of a material having an electro-optic effect, it is necessary to cover at least the shutter area with a heat-resistant resist film that has different etching characteristics from the electrode material. When forming a metal film for electrodes by reverse sputtering or sputtering,
The resist film is not altered in quality, and the metal film portion for the electrode is not contaminated.

Further, when manufacturing an optical shutter as in the present invention, there is no need to perform troublesome operations such as exposing and developing a photoresist to form a pattern.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings.

First, in this embodiment, as a plate-shaped body (1) made of a material having an electro-optical effect, as shown in FIG. PLZT (1) was prepared. Note that when PLZT (1) is used as in this embodiment, an optical shutter that can be driven with a low voltage can be obtained. Also, this PLZT (1)
Specifically, the composition is 9/65/35 and the length is 1
00 opening 9 width 5.0 mm and thickness sail 5 opening were used.

Then, as shown in FIG. 1(b) and FIG. 2, a chromium film (2) of approximately 2,000 layers, which will become a resist film (2), is formed on the entire surface of one side of this PLZT (1) by sputtering. Shina. Note that this chromium film (2) is a stable film with heat resistance, and has different etching characteristics from the aluminum film (7) for electrodes, which will be described later. 12). In this case, the aluminum film (7) for electrodes formed on the chromium film (2) is also removed at the same time.

Hereinafter, for convenience of explanation, as shown in FIG. 1(b), PL
The longitudinal direction of ZT(1) is the X axis, and the width direction, that is, the direction perpendicular to the X axis is the Y axis.

Then, the PLZ with the chromium film (2) formed as described above
The center of T(1) was precisely cut along the entire length of PLZT(1) in the X-axis direction to form a groove (3) for a common electrode as shown in FIG. This cutting process was performed with a dicing saw, and a diamond cutter with a blade thickness of 40 μm was used as the cutter. In addition, the groove (3) has a groove width of 104 μm.
m.

A groove having a depth a of 160 μm from the surface of PLZT (1) was formed.

Furthermore, precision cutting is performed over the entire length of the PLZT (1) on both sides of the groove (3) parallel to this, that is, in the X-axis direction, at a constant interval from both sides of the groove (3). As shown in the figure, grooves (4) and grooves (5) for individual electrodes were formed. These grooves (4).

In case (5), the shapes are the same, the groove width is 80 μm, and the groove depth is b.
was set to 120 μm, and was formed shallower than the groove depth a of the common electrode groove (3). Also, the distance between the groove (4) and the groove (5) with respect to the groove (3), that is, the shutter portion (11), (1
2>, the width of the convex part is 60 μm, and the width of the shutter parts (11) and (12), the groove (3) and the edge (
The depths a and b in 4) and (5) can be arbitrarily selected depending on the performance required of the optical shutter array and within the accuracy of precision cutting. However, the condition is a>b.

Next, line the outside of the groove (4) and the edge (5) with these 71
The shutter part (11) was cut continuously from 1 (4) and (5) to the end at a depth d of 80 μm, as shown in Fig. 3.
, chromium film (2) other than (12) was removed.

The diamond cutter used here may be the same as that used in the previous cutting process, or may be a thick cutter. For example, when using the same cutter, -
Since the cutting width per cycle is about 50 μm, the Y of the cutter
The feed pitch in the axial direction is 30 μm, which is smaller than this cutting width.
Cutting should be done at a certain level. When the chromium film (2) other than the shutter parts (11) and (12) is removed in this manner, the surface of the area where the chromium film (2) has been removed becomes rough due to cutting.

Next, after thoroughly cleaning the PLZT (1) after the above processing, an aluminum film (7) was formed as a metal film (7) for an electrode on the entire processed surface of this PLZT (1). . Here, in forming the aluminum film (7), in order to improve its adhesive strength, cleaning treatment and sputtering using reverse sputtering were performed under the conditions shown in Table 1 below, and the PLZT (1) was processed. An aluminum film (7) having a thickness of about 4 μm was formed over the entire surface.

Table 1 Even when aluminum wX (7) is formed in this way, there is no change in the chromium film (2) remaining on the shutter parts (11) and (, 12), and the aluminum film (7) No contamination was observed in this area. Also,
In the area where the chromium film (2) has been removed and the surface has been roughened, the contact area with the aluminum film (7) increases, and the aluminum film (7) engages with the unevenness of the surface and is strongly bonded. Became.

Next, PLZT (1) provided with this aluminum film (7)
) was again cut using a cutting tool to determine the shape of each shutter part (11), (12). In this cutting, a diamond cutter having a tip angle θ of 60° and a blade thickness of 200 mm as shown in FIG. 5 was used. Then, triangular grooves (6) were sequentially cut at a required groove pitch using this cutter at an angle of 64° with respect to the X-axis direction. Here, the pitch is about 144
μm, and the groove width and depth e of this groove (6) are determined by the monitor attached to the dicing saw.
) The groove width at the upper edge, that is, the width at the surface edge is 7
In addition to setting the groove depth to 2 μm, the groove depth e is
The cutting depth was approximately 60 μm shallower than the cutting depth d used to remove the chromium film (2). When the grooves (6) are cut in this way, the grooves (6) are cut in the shutter parts (11) and (12>), as shown in FIG. ) and (12) are determined, but in the electrode part, the groove depth e of this groove (6) is shallower than the cutting depth d when removing the chromium film (2) as described above. The aluminum film (7), which is not cut and becomes an electrode, remains continuous without being separated.

Then, in the center of this groove (6), a groove (6') with a groove width of about 20 μm and a groove depth C of 140 μm is formed using a diamond cutter with a blade thickness of 15 μm, and each shutter part (11) , (12) are deeply separated, and PLZ
The surface of T (1) and the aluminum film (7) in the grooves (4), <5) are cut at this angle (6°), and the shutter elements (11), (12) and individual electrodes (14) are cut.
, (15) and electrode lead section (14ft).

(15, ff) was separated.

Here, if we organize the relationship between cutting depth in each cutting,
As shown in FIG. 6, the condition of a>b>c>die is satisfied.

In this way, the groove depth C (・140 μm) of groove (6′) is made shallower than the edge depth a (・160 μm) of groove (3), while the groove depth of grooves (4) and (5) b (□120μm)
If it is made deeper, cutting this groove (6') will cause PLZ
The surface of T (1) and the aluminum film (7> in m (4), (5) are cut at this 7IIt (6') location, and each shutter part (11), (12) and individual electrode (14) are cut. ).

(15) and the electrode lead parts (14g>, (15ft>) are formed separately, while the groove (3) which becomes the common electrode (13)
The aluminum film (7) on the bottom surface is not cut and remains in a continuous state. That is, by cutting this groove (6'), parallel individual electrodes (14) and (15) can be made at the same time as the three-dimensional shutter parts (11) and (12). Therefore, as in the method disclosed in JP-A-61-38927, it is a cumbersome process such as forming a pattern using photoresist or removing a part of the metal thin film in the groove with a laser or the like to provide an independent electrode. This makes it possible to greatly simplify the manufacturing process.

Note that the aluminum film (7) at the cutting location is scraped off by this cutting of l (6'), but since the aluminum film (7) around it is strongly adhered to the PLZT (1), it will not peel off during cutting. There was no way I would do that.

In addition, the groove depth e of the groove (6) is made shallower than the cutting depth d when the chromium film (2) is removed, and when cutting the groove (6), the aluminum film (7 ) is not cut and is separated by a groove (6'), so the electrode lead part (14ffl).

(1542) is formed wide so that it can be easily connected to an external drive circuit.

Then, as the final step of the manufacturing process, each shutter part (11)
, (12) A chromium film (2) formed on the window on the top surface.
) is chemically etched using a solution containing ceric ammonium nitrate and perchloric acid, and this chromium film (2
) and an aluminum film (7) formed thereon.
was peeled off to open the window section on the upper surface of each shutter section (11), <12). At this time, the aluminum film (7) attached to other parts was not peeled off.

As described above, as shown in FIG. 4(b), an optical shutter array (10 ) was obtained.

In the optical shutter array (10) manufactured in this way, even though the shutter parts (11) and (12) were formed by cutting, almost no light leaks from these edge parts due to processing distortion. It is now possible to obtain extremely high optical contrast. This is because the upper edges of each shutter section (11) and (12) are rounded by grooves (6), and as shown in FIG. 7(b), the light incident on the etched portions is It is thought that this is a lick that is reflected at this cornered area.

Next, FIG. 8 shows an example in which this optical shutter array (10) is used by being connected to an external circuit. In the figure, (20) is a drive circuit (including a semiconductor chip-shaped circuit) that applies a drive pulse to drive each shutter part (11) of the shutter array (IIA), and (21) is the shutter array (12A).
This is a drive circuit that drives each shutter section (12).

The drive circuit (20) is connected to each electrode lead part (li) of the odd-numbered shutter part (11) in the shutter array (IIA), while the drive circuit (21)
It is connected to the individual electrode lead parts (15β) of the even-numbered shutter parts (12>) in the shutter array (12A).

The drive circuits (20) and (21) are operated in time division, and the ninth
As shown in Figures (a) and (b), a single line image is formed by the shutter action of two rows of shutter arrays (IIA) (12A) based on image information. The time difference is adjusted to be synchronous with the rotational speed of the image forming unit, such as the photoreceptor drum. By driving in this way, this optical shutter array (10) has a pitch of 80 μm, that is, 12
．． It is now possible to achieve a high resolution of 5 dots/mm.

In this embodiment, an example is shown in which a chromium film is used as the resist film, but the resist film is not limited to such a film, and it is also possible to use molybdenum, polyimide resin, or the like. In addition, in the case of a resist film using molybdenum, chemical etching should be performed using a solution containing phosphoric acid and nitric acid, and in the case of a resist film using polyimide resin, chemical etching should be performed using a hydrazone solution. According to
The aluminum film (7), which is the electrode material, is not peeled off,
Only these resist films are now removed.

Furthermore, when forming a resist film made of polyimide resin, baking is usually performed at about 350°C.
never changed.

E. Effects of the Invention As detailed above, the method for manufacturing an optical shutter according to the present invention does not require troublesome work such as exposing and developing a photoresist to form a pattern, and it is possible to easily manufacture an optical shutter. In addition, in this invention, a heat-resistant resist film having different etching characteristics from the electrode material is used to cover the shutter region of the plate-shaped body made of a material having an electro-optical effect. Therefore, when a metal film for an electrode is provided by reverse sputtering or sputtering, there is no possibility that the metal film for the electrode is contaminated due to deterioration of the resist film or the like.

As a result, gold fi for electrodes with high adhesion strength was applied to the optical shutter.
In addition to being able to form t and M, contaminants do not enter between the shutter and the electrode and have a negative effect when applying voltage from the electrode to the shutter, and the light and shutter can be stably driven. Now you can.

Furthermore, the resist film does not change in quality and become difficult to remove by etching, and the shutter can now be opened successfully by etching.

[Brief explanation of the drawing]

Figure 1 (a), (b), Figure 2, Figure 3 and Figure 4 (
a) and (b) are explanatory diagrams of the manufacturing process of an optical shutter array according to an embodiment of the present invention, and FIG. 2 is a partially enlarged sectional view taken along line I-I in FIG. 1(b), and FIG. is a sectional view of the diamond cutter used in the same example, FIG. 6 is a sectional view taken along the line ■-■ in FIG. 4(b), and FIGS. 7(a) and (b).
are a plan view and a front view of the shutter element of the same example,
FIG. 8 is a connection diagram of the optical shutter array and drive circuit of the same embodiment, FIGS. 9(a) and (b) are explanatory diagrams of shutter driving of the same embodiment, and FIG. 10 is a diagram of FIG. 4(b). FIG. 2 is a sectional view taken along line III-I of FIG. (1)...Plate body with electro-optic effect (PLZT)
, (2)...resist film (chromium film), (3)...
Groove for common electrode, (4>, (5)... Groove for individual electrode, (7)... Metal film (aluminum film) for electrode, (
11), (12)...Shutter section. Patent applicant Minolta Camera Co., Ltd. Agent
Patent Attorney Katsuaki Matsukawa Figure 1 (a) Figure 3 (also) Figure 4 Figure 4 (b) 5i Figure 5 1-D-→ Figure 6 Figure 7 (a) Figure 8↓ Figure 9 (a) Figure 10

Claims (1)

[Claims] 1. On at least one side of a plate-shaped body made of a material having an electro-optical effect, a heat-resistant resist film having etching characteristics different from that of the electrode material is provided to cover at least the shutter region, and a groove for the electrode is formed. Thereafter, a metal film for an electrode is formed thereon, and the resist film is removed from the shutter portion by etching to open the shutter portion.