JPH0296711A - Production of optical shutter element - Google Patents

Abstract

PURPOSE:To form the optical shutter element without having damages even if the light transmission surface is of an intricate shape and is very small by previously subjecting the surface of a base plate intended with be formed with the light transmission surface to mirror finishing, then removing the resist applied over the entire surface at the time of required machining and providing electrode metal films by plating. CONSTITUTION:Planar substrate surfaces 11a, 11b are previously subjected to mirror finishing and thereafter, the resist 12 is applied on the surfaces to form rugged parts 13a, 13b consisting of a required shape at the time of depositing and forming electrodes to the prescribed position of the substrate surfaces which have an electro-optic effect and are formed with the required rugged parts. The metallic film 14 for the electrodes is formed on the substrate surface from which the resist 12 is removed by an electroless plating method and the resist 12 remaining on the substrate surface is removed by a chemical treatment. Since the metallic film sticking to the parts exclusive of the electrode parts is deposited via the resist, the unnecessary metallic film can be removed by the chemical treatment which dissolves the resist. The need for machining to remove the film is eliminated and the film is efficiently removed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application The present invention relates to a method for manufacturing a light shutter element that utilizes the electro-optic effect, particularly a small light shutter element whose light transmitting surface and electrode portion have a relatively complicated shape. In this regard, the four major substrates are mirror-finished and coated with resist, and after forming the required uneven surfaces, an electroless plating film for electrodes is applied, and the remaining resist is removed. A method of manufacturing an optical shutter in which a uniform electrode film is formed at a predetermined position of a shape (this invention relates).

BACKGROUND TECHNOLOGY Optical shields using electro-optic effects are produced by using (PbLaXZrTi) between a pair of polarizers whose polarization directions are orthogonal to each other.
) Oa (hereinafter referred to as PI, ZT), LiNbO3, B
It is made of a ceramic substrate such as i128i020, and 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. It is used in various directions.

As the optical shutter element, as shown in Fig. 2, a substrate (1
) into the concave groove (2x2) formed in the electrode material (
A structure having a groove-shaped electrode formed by depositing 3×3) is known.

In such a groove-shaped electrode configuration, the electric field effectively penetrates and distributes to the inside of the substrate (1), so it is possible to reduce the driving voltage. Since there is no way to efficiently and uniformly deposit the electrode material (3x3), there are restrictions on the depth and width of the grooves (2) and (2), which satisfies the recent demands for miniaturization and low driving voltage. I couldn't let it go.

Therefore, as a manufacturing method that solves the above problem, the inventor first deposited a metal film for electrodes on the entire surface of the substrate (1) on which grooves (2×2) were formed in advance by electroless plating, and then A method was proposed (Japanese Patent Laid-Open No. 62-231212) in which the metal film on the other side (2×2) is left and the metal film on the other side is polished away and the light transmitting surface (4) is polished to a mirror finish.

Problems with the Prior Art According to this method, it is possible to uniformly adhere electrode material with high adhesion strength even to narrow and deep grooves, which have been difficult to form using conventional methods such as sputtering and vapor deposition. Therefore, it is possible to provide an optical shutter element that can reduce electric resistance and drive voltage, and further reduce transmission loss.

However, in this field, as miniaturization is increasingly required, 1. Since various shutter functions are required, the dimensions of the light transmitting surface and the groove are becoming more restricted, and the shape tends to become more complicated.

However, although the method proposed above has various advantages in forming electrode parts, it is not necessarily efficient in terms of workability, yield, etc. because it relies on mechanical processing for removing unnecessary metal films and forming light-transmitting surfaces. This is not a practical method, especially when the light-transmitting surface is small and has a complicated shape, making it virtually difficult to achieve a mirror finish, and there is also a concern that a portion of the light-transmitting surface may be chipped.

Purpose of the Invention The present invention aims to solve the above-mentioned problems, and in particular, to provide an electrode film that is uniform and has high adhesion strength even in complex shapes such as narrow and deep grooves when manufacturing extremely small optical shutter elements. The object of the present invention is to provide a method for manufacturing an optical shutter element that can form a mirror-polished light-transmitting surface with a small and complicated shape.

Summary of the Invention This invention provides the following methods: - When forming an electrode at a predetermined position on a substrate surface that has an electro-optical effect and has a required unevenness, the surface of the plate-shaped substrate is mirror-finished in advance, and then a resist is applied. ■ Form an uneven part of the desired shape on the surface of the substrate coated with resist ■ Form an electrode metal film on the substrate surface from which the resist has been removed by electroless plating ■ Remain on the substrate surface This is a method of manufacturing an optical shutter element, characterized in that electrodes are formed by a method in which a resist is removed by chemical treatment, and then a resist is removed by chemical treatment.

In other words, the present invention eliminates the need for mirror finishing when the light transmitting surface has reached its final dimensions through groove processing, cutting, etc. by applying a mirror finish in advance to the surface of the substrate on which the light transmitting surface is to be formed. In addition, after applying resist to the mirror-finished surface, we perform necessary cutting processes such as groove machining to remove the resist only in designated areas, and perform electroless plating to firmly form the metal film only on the required electrode areas. Since the metal film that adheres to areas other than the electrode area is deposited through the resist, unnecessary metal films can be removed by removing the resist using a chemical process that dissolves the resist. This eliminates the need for accompanying machining, allows for efficient removal, and achieves the above object.

Structure of the Invention Substrates used in this invention include PLZT and LiNb, which have electro-optic effects such as Pockels effect and Kerr effect.
A known ceramic substrate such as O3, B112Si020, etc. can be used.

The surface of the substrate, which will eventually become a light-transmitting surface, can be given a mirror finish using a known lapping technique.

As the resist, known resists such as alkali-developed resists and solvent-based resists can be used, and as the coating method, a spin code or the like can be used.

Mechanical processing using a peripheral blade cutter, laser processing, etc. can be used as a method for forming uneven portions of the desired shape on the substrate surface, and the grooves and light transmitting surfaces that form the electrode portions are processed into the desired shape by this processing. .

Furthermore, an electrode metal such as Ni, Cu, or Au is typically 1-3p coated on the entire substrate having uneven parts by electroless plating.
When deposited with a film thickness of approximately m, the electrode portion can be formed uniformly and with a predetermined adhesion strength, particularly in the processed portion, that is, the resist removed portion.

Next, when the resist is chemically removed with an alkali or a solvent, the unnecessary metal film deposited on the resist surface in the step is removed, and the metal film is deposited only at predetermined positions where electrode portions will be formed. The Rukoto.

Further, the light transmitting surface coated with resist after mirror finishing is not damaged by the process, and the resist removal can be completed.

Based on the Drawings (Disclosure of the Invention) FIG. 1 a-1 is a perspective explanatory view showing a manufacturing process according to the present invention.

Here, the optical shutter element will be explained using the simplest configuration as an example, but the present invention can be applied to the production of optical shutter elements of any configuration including more complex configurations, An example will be described in which a Ni plating layer is applied to a metal film for an electrode using a quadrangular resist (PHT manufactured by Tadachi Kasei Kogyo Co., Ltd.). Furthermore, in the drawings, the uneven portions formed on the substrate are exaggerated.

The substrate (10) shown in Fig. a is cut out by slicing from a PLZT sintered body having a composition ratio of 9/65/35, and then both main surfaces (lla) (Ilb) are cut out by lapping. Mirror finished, 10mm on each side, 0.5mm thick
It is a square plate of mm.

As shown in figure b, the entire surface of the board with both main surfaces mirror-finished,
A resist (12) is applied to a thickness of about lpm.

When forming concave grooves on the surface of the substrate using the above substrate, the process shown in diagrams CE is performed, and when forming convex protrusions, the process shown in diagrams rh is performed to form an extremely small light transmitting surface. When forming, it is manufactured through the steps shown in Figure i-1.

Step of forming a concave groove shown in figures ce When forming a concave groove, a groove (13aX13b) is formed on the surface of the substrate (10) using a peripheral blade cutter (see figure 0).

At this time, the resist (12) is mechanically removed from the processed grooves (13aX13b) at the same time as the processing.

Furthermore, the entire surface of the substrate (10) is coated with a thickness of I by electroless plating.
pm Ni plating layer (14) is deposited (see figure d).

At this time, the Ni layer for the electrode is formed to adhere uniformly to the groove portions (13aX13b) with a predetermined adhesion strength.

In this way, a substrate (
When the unnecessary Ni plating layer (14) deposited on the resist (12) is removed together with the resist (12) by immersing the resist (10) in an alkaline solution, a predetermined groove (
Ni plating layer for electrodes (14
) remains, and an optical shutter element having a desired groove-shaped electrode having a mirror-finished light transmitting surface (15) is obtained (see Figure 0).

According to the above method, the light transmitting surface (15) with a radiation of 10\Im
A good groove-shaped electrode with a width of 10 pm and a depth of 500 pm could be formed by sandwiching the .

As shown on the process side of forming a convex shape on f~,
A convex protrusion (1) is cut on the surface of the board (10) using a peripheral blade cutter.
6aX16b).

At this time, the entire resist (12) except for the upper surfaces of the processed convex projections (16a) and (16b) is mechanically removed at the same time as the processing.

Next, a metal film (14) for an electrode is deposited on the entire surface of the substrate (10) by electroless plating. (See figure g) Furthermore,
When the resist (12) is removed using an appropriate solvent, the upper surface of the elbow convex projection (16aX16b) becomes the light transmitting surface (15).
aX15b), and the groove portion (13) and the flat portion (17a) (1
7b), an electrode layer can be formed (see figure h).

i = 1 The process of forming an extremely small light transmitting surface shown in Figure i and the following steps are for forming a light transmitting surface with an extremely small area in which the effects of this invention are most exhibited. (10) Form a convex protrusion (16) on the surface with a peripheral edge.

A Ni plating layer (14) for electrodes is deposited on the entire surface of the substrate (10) by electroless plating (see Figure 0).

Thereafter, the resist (12) is removed (see figure k), and the light transmitting surface (15) is further processed with a peripheral blade cutter until the required dimensions of the light transmitting surface (15) are obtained. 15) can be obtained.

According to the process shown in Figure i-1, a rectangular light-transmitting surface with a negative side of 10 pm could be formed at the tip of a convex projection with a height of 500 pm.

In each of the above-mentioned processes, an example was explained in which a peripheral blade cutter was used to process the uneven parts, but by using the laser processing method, it is possible to create an optical shutter element with a complex shape and a minute light-transmitting surface. can be manufactured.

Effects of the Invention As shown above, the manufacturing method according to the present invention is characterized in that after the resist coated on the entire surface is removed during required machining, an electrode metal film is provided by plating, and by such electrode deposition treatment, Since it can be processed into the required shape and dimensions using a substrate that has been mirror-finished in advance, there is no need to mirror-finish the light-transmitting surface after processing, and even if the light-transmitting surface has a complex shape and is minute, it will not be damaged. can be formed.

In addition, the present invention employs an electroless plating method to deposit the metal film for the electrode, and can efficiently form a narrow and deep groove-shaped electrode, thereby providing an optical shutter element with reduced driving voltage. can.

Furthermore, since the metal film deposited on unnecessary parts is deposited through a resist, it can be easily removed by chemical treatment, making it easy to work and providing optical shutter elements at low cost. can.

[Brief explanation of drawings]

FIG. 1 a-1 is a perspective explanatory view showing the manufacturing process according to the present invention. FIG. 2 is a perspective explanatory view of the optical shutter element. 1.10...Substrate, 2...Groove portion, 3...Electrode material, 11a, llb...Main surface, 12...Resist, 1
3.13a, 13b-grooves, 14-Ni plating layer, 15
．． 15a, 15b--light transmitting surface, 16a, 16b=-convex protrusion, 17a, 17b...flat surface.

Claims (1)

[Claims of Claims] 1. When forming an electrode at a predetermined position on a substrate surface having an electro-optic effect and having a required unevenness, (1) a resist is applied to the surface of a plate-shaped substrate which has been mirror-finished in advance; Coating (2) Forming irregularities of the desired shape on the surface of the substrate coated with resist (3) Forming a metal film for electrodes on the substrate surface from which the resist has been removed by electroless plating (4) A method for manufacturing an optical shutter element, characterized in that electrodes are formed by the above-mentioned procedure of removing resist remaining on the substrate surface by chemical treatment.