JPS62231212A - Production of optical shutter element - Google Patents

Abstract

PURPOSE:To easily form an optical shutter element by grinding away the other metallic film except the metallic films formed in grooves or further depositing and forming a pair of power feed electrodes which connect the parallel arranged grooves for the electrodes alternately at every other grooves. CONSTITUTION:A substrate 10 is sliced to a square plate shape from a sintered PLZT body having 9atom% substitution quantity of La with Pb and 65/35 Zr/Ti ratio. Such substrate is provided with the grooves by machining with a cutter edged on the outside periphery at the set width of the light transmission surface. More specifically, the grooves 11, 12 for the electrodes cut from one long side end toward the other side end are alternately disposed in such a manner that the directions thereof are made opposite from each other. The substrate is then subjected to a stress relief heat treatment in the atm. and in succession, the substrate 10 is immersed in an electroless copper plating liquid and is subjected to an electroless copper plating treatment by which a copper film 13 for the electrode is deposited over the entire surface of the substrate 10. Both the main faces of the substrate 10 are polished to the required roughness by a lapping machine and the short side end faces are cut.

Description

[Detailed Description of the Invention] Field of Application The present invention relates to a method of manufacturing an optical shutter element using an electro-optic effect, and has a structure in which a pair of comb-shaped groove electrodes are opposed and their grooves are arranged parallel to each other. The present invention relates to a method of manufacturing an optical shutter element having deep and narrow electrode grooves.

BACKGROUND ART An optical shutter that utilizes the electro-optic effect uses (PbLa) (ZrTL) between a pair of polarizers whose polarization directions are orthogonal to each other.
) o3. LLNbOs, BL+z SLO2o
It is constructed by arranging an optical shutter element whose electric field direction forms an intersection angle of 45° with the polarization direction of incident light, and is used as a writing device of an optical printer, a shutter of an optical camera, etc., or a three-dimensional Multipurpose applications such as eyeglasses and protective goggles for welding are being considered.

As such an optical shutter element, as shown in FIG. 6, a pair of fence-shaped planar electrodes (2) and (3) are placed on each of the front and back surfaces of a substrate (1) which has been mirror-polished in advance, with the toothed portions alternately arranged. Place the power supply part (2a) (3a) and the electrode part (
2b) A so-called planar electrode type structure consisting of (3b) is known.

However, in the above configuration, since the required electrode portions (2b) and (3b) are formed on the surface of the substrate (1), the electric field is
) There are problems such as not penetrating into the inside sufficiently, and it is necessary to increase the driving voltage to concentrate on the surface of the substrate (1).
Since the electrodes are formed on mirror-finished surfaces, they have weak adhesion and are easily peeled off and damaged by application of high driving voltages.

As an optical shutter element having a structure that eliminates this problem, a so-called groove type structure shown in FIG. 7 is known. That is, the substrate (1
) are provided with a large number of parallel grooves, and every other parallel groove is electrically connected alternately to power supply electrodes (4a) (5a) formed on both end surfaces of the substrate (1) to form an electrode portion (4b). (5b
) with groove-shaped electrodes (4 x 5) arranged.

In the groove-type electrode (4×5) configuration in which the electrode material is deposited on the groove surface, the electric field effectively penetrates and distributes to the inside of the substrate (1), so the driving voltage can be reduced compared to the configuration shown in FIG. 6 above. However, in order to further reduce the driving voltage and expand the light transmission area of the substrate (1) as much as possible to reduce transmission loss, the groove depth of the groove electrode should be made deeper and the groove width narrower. There is a need.

It is difficult to apply the required electrode material to the concave grooves of the groove-shaped electrode (4×5) using known methods such as sputtering and vapor deposition, and a method of applying a conductive base is usually adopted. However, in order to adhere the electrode material uniformly and with the required adhesion strength to the groove surface, the depth and width of the groove are inevitably limited, making it difficult to reduce the driving voltage and transmission loss. Moreover, the manufacturing process is complicated, making it unsuitable for manufacturing on an industrial mass production scale, and there is a strong need for improvement in manufacturability.

Purpose of the Invention The object of the present invention is to provide a manufacturing method that can easily manufacture an optical shutter element consisting of a pair of comb-shaped groove electrodes facing each other with their grooves arranged in parallel. The object of the present invention is to provide a method for manufacturing an optical shutter element that can provide a deep and narrow groove-type electrode having a metal film.

Structure of the Invention The present invention provides an electro-optic effect on the surface of a plate-shaped substrate.
After forming a large number of electrode grooves arranged in parallel or further forming a power feeding electrode groove, and forming an electrode metal film on the entire surface of the substrate by electroless plating, at least the metal film formed in the grooves is left. , manufacturing an optical shutter element characterized in that the metal film on the other surface is removed by polishing, or further a pair of power supply electrodes are formed by alternately connecting every other electrode groove arranged in parallel. It's a method.

To explain in detail, the manufacturing method according to the present invention has electro-optic effects such as Pockels effect and Kerr effect (PbL
a) (ZrTi) 03 (hereinafter referred to as PLZT).

LL Takashi 03. The required electrode grooves are formed on a known ceramic substrate such as BL+2SLOro by a method such as machining with a peripheral blade cutter, laser processing, etching, etc. selected according to the substrate composition and the shape and size of the groove, etc. Accordingly, heat treatment is performed to remove strain, and Qt and NL are applied to the entire substrate by electroless plating.

Deposit an electrode metal such as M at a film thickness of usually about 11s to 3IXn, and then cover the metal film formed in the electrode groove and the metal film in the required parts so as to connect to this and form the power supply electrode. The metal film on the other side is removed by polishing or cutting, and the light transmitting surface is polished to a mirror finish, or the metal film on the other side is polished while leaving the metal film formed in the electrode groove. At the same time, the light transmitting surface is polished to a mirror finish, and two power feeding electrodes are separately formed to alternately connect every other electrode groove.

The manufacturing method according to the present invention can uniformly form an electrode metal film such as Cu, NL, Al1, etc. on the surface of a deep and narrow groove with high adhesion strength, and is superior to optical shutter elements manufactured using conventional methods. , low electrical resistance and driving voltage;
Moreover, transmission loss can be reduced.

DISCLOSURE OF THE INVENTION BASED ON DRAWINGS FIG. 1 is a perspective explanatory view showing a manufacturing process according to the invention. 2 to 5 are perspective explanatory views of an optical shutter element according to the method of this invention. Note that in all the drawings, the groove portions are exaggerated.

To explain the manufacturing process according to the present invention based on FIG. 1, the substrate (10) has a substitution amount of 1 with respect to a circle of 9 at.
, a rectangular plate shape of width 30 + rur + x length 40 ff 1 m x thickness 0.5 mm obtained by slicing from a PLZT sintered body with a Zr / Ti ratio of 65/35.

Next, the substrate (10) is machined using a peripheral blade cutter to set the light transmission surface width to 0.21T1m, and the groove width to 0.02T1m.
A groove with dimensions of mm x depth 0.3 mm is provided. That is, as shown in FIG. 8, the electrode grooves (11) and (12) cut from one long side end to the other side end are alternately arranged so that the directions are reversed.

After the above-mentioned groove processing, the substrate (10) was subjected to strain relief heat treatment for 1 hour in the air at 500°C, and then immersed in an electroless copper plating solution at 60°C for 30 minutes. Electroless plating is applied to the entire surface of the substrate (10) to a thickness of O.
2 mm of electrode copper vA (13) was deposited.

Roughly polish both main surfaces of the substrate (10) to the required roughness using a lapping machine, and cut the short side end faces to form the inside of the electrode grooves (11) and (12) and the long side end faces. Copper film for electrodes (
13), and as shown in Figure D, the copper film for electrodes on the long side end face of the substrate (10) is attached to the power supply electrodes (14a) (15a).
It has groove-shaped electrodes (14) and (15) with a light transmitting surface (1
6) The mirror-polished optical shutter element can be manufactured by one wire.

The optical shutter element shown in FIG. 2 is manufactured by forming a plurality of parallel electrode grooves on the substrate (20) by laser processing, leaving strips on both ends of the main surface in the longitudinal direction. A required metal film for electrodes is deposited by electroless plating, and then the entire other surface is polished, leaving the metal film for electrodes in the grooves, to form groove-shaped electrode parts (21b) (22b). A metal film for electrodes is roughly coated on the band-shaped portion to form the power feeding electrode portions (21a) (22a), and a pair of comb-teeth groove type electrodes (21) (22) are formed. It is.

The optical shutter element shown in Fig. 3 is made by laser processing.
The substrate (30) has a longitudinal power feeding electrode groove (31a).
(32a) and a large number of electrode grooves (31b) (3
2b) a pair of comb-shaped electrode grooves (31) (32)
A required electrode metal film is deposited on the entire substrate (30) by electroless plating, and the surface is polished to remove all metals other than the metal film in the electrode grooves (31) and (32). The film is removed, the light transmitting surface between the grooves is made into a mirror-polished surface, and groove-shaped electrodes (31) and (32) having a metal film for electrodes uniformly and firmly adhered to the groove surface are formed.

The optical shutter element shown in FIG. 4 has a disk-shaped substrate (40).
Grooves, one of which reaches the circumferential end surface, are arranged in alternating directions by machining on the main surface, and then a metal film of the required thickness is deposited by electroless plating, and the grooves are formed on both main surfaces as well as in the groove direction. By removing the metal film on the opposing circumferential surface part (43) in the diametrical direction perpendicular to , a groove-shaped electrode ( 41) and (42), and has a mirror-polished light transmitting surface.

The optical shutter element shown in Fig. 5 is made by laser processing.
A power feeding electrode groove (51a) is provided in the circumferential direction on the substrate (50).
(52a) is provided with a pair of comb-shaped electrode grooves (51) and (52) having a large number of electrode grooves (51b) and (52b) that are continuous and parallel to the diameter direction, and the substrate (50) is A required metal film for electrodes is deposited by electroless plating, and the surface is roughly polished to remove all metal films except those in the electrode grooves (51H52), and the light-transmitting surface between the grooves is removed. Groove-shaped electrodes (51) and (52) are formed with a mirror-polished surface and a metal film for electrodes uniformly and firmly adhered to the groove surface.

Effects of the invention Incidentally, using the optical shutter element shown in the first diagram, polarizers are placed on both sides of the optical shutter element to form a groove in the optical shutter, and the wavelength is 0.6.
When 331 seconds of laser light is transmitted, the driving voltage is 75V.
It showed good operation.

Conventional optical shutter elements with a pair of comb-shaped groove electrodes manufactured by applying conductive paste have been manufactured on a mass production scale (the groove dimensions were limited to approximately 0.1 mm in both width and depth). However, in the manufacturing method according to the present invention, a groove-shaped electrode having a uniform metal film with high adhesion strength is formed to a depth of 0.5 mm.
, it is possible to make the groove deep and narrow to about 0.01 to 0.02 mm, and it is possible to reduce the driving voltage and significantly reduce the transmission loss as the transmission area increases. An inexpensive metal film such as copper can be easily deposited in a short time, the number of manufacturing steps is small, and an optical shutter element can be provided at low cost.

[Brief explanation of drawings]

FIG. 1 is a perspective explanatory view without showing the manufacturing process according to the present invention. 2 to 5 are perspective explanatory views of an optical shutter element according to the method of this invention. 6 and 7 are perspective explanatory views of an optical shutter element according to a conventional method. 1, 10.20.30.40.50...substrate, 11.
12...Groove for electrode, 13...Copper film for electrode, 14.1
5... Groove electrode, 14a, 15a, 21a, 2
2a, 41a, 42a... power feeding electrode, 21b,
22b, 31b, 32b, 51b, 52b・
...Groove for electrode, 31a, 32a, sia, 52a
...Electrode groove for power feeding, (A) (
B) (C) (D) Figure 2 Figure 3 Figure 6 h Figure 7

Claims (1)

[Claims] 1. On the surface of a plate-shaped substrate having an electro-optic effect, a large number of electrode grooves arranged in parallel or further electrode grooves for power feeding are formed, and a metal film for electrodes is formed on the entire surface of the substrate by electroless plating. At least the metal film formed in the groove is left and the metal film on the other side is removed by polishing, or further,
1. A method of manufacturing an optical shutter element, characterized in that a pair of power feeding electrodes are formed by alternately connecting every other electrode groove arranged in parallel.