JP2008152027A - Optical component and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical component which can make the manufacturing time an ordinary time and can suppress a product cost. <P>SOLUTION: On one side surface of the optical component, chemical reinforcement treatment is performed and, thereafter, an antireflection film is deposited. On the other side surface of the optical component, an antireflection film on which a filter film is deposited has a multilayer structure of the order of three layers. The filter film has a multilayer structure of the order of 30 layers. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical component such as a wavelength plate, a polarizing plate, a beam splitter, and a mirror used in an optical pickup for a recorder such as a CD / DVD / Blue-Ray, a projector, an exposure apparatus, and a semiconductor inspection apparatus, and a manufacturing method thereof.

  Conventionally, for example, as shown in paragraph 0026 of FIG. 1 and FIG. 2, an alumina film that is almost equal to the thermal expansion coefficient of the AR coat is used as the optical thin film to be formed on the back surface of the glass substrate, and the surface side is subjected to compressive stress. By applying a tensile stress Fb to the back side of the glass substrate where the warpage has occurred and canceling out the respective stresses (Fa, Fb) caused by the AR coat and the alumina film, the warp of the glass substrate is eliminated. It has been known.

  Further, in paragraph 0030 and FIG. 4 of Patent Document 1, a thin resin polarizing plate having an AR coat formed on one surface is laminated on a thin resin wave plate, and the AR coat and the alumina film are respectively laminated. There is described a laminated optical component in which a glass substrate formed on a main surface is bonded to the main surface of a resin wave plate opposite to the main surface on which the thin resin deflecting plate is laminated.

Further, for example, as shown in the claims of Patent Document 2, re-chemical strengthening is performed on the difference in depth of each of the compression strain layers formed on the front surface and the back surface of the glass substrate by chemical strengthening. Describes a method for producing a glass substrate for a recording medium which is reduced by the above.
JP 2004-258377 A Japanese Patent No. 2998952

  When the above-described conventional optical components are applied to DVD, CD optical pickup-related startup mirrors, beam splitters, etc., the required surface accuracy is severe and the optical properties are also environmentally resistant. When an environmental test such as a temperature test and a vibration test was performed using the alumina film of Patent Document 1, peeling occurred between the glass substrate and the glass substrate.

  Therefore, when applying a vapor deposition method to a normal optical component, there exists a problem of a wavelength shift and it is difficult to manufacture. Therefore, film forming methods such as vapor deposition (IAD, RF-ion sputtering) and sputtering using an ion process are used. However, when the film forming method described above is used, the internal stress (compression) of the film itself becomes strong, and when several tens of multilayer films are stacked, the compressive stress becomes 0.2 to 0.3 GPa.

  As shown in FIG. 2A, for example, when about 30 layers of the filter film 2 are formed on one surface of the wave plate 1, bending occurs due to internal stress of the film itself.

  In order to alleviate this, as shown in FIG. 2B, a stress relaxation layer 3 (stress relaxation layer) is formed on the opposite surface (back surface) of the wave plate 1 to a thickness approximately equal to that of the filter 2. The manufacturing time is about 2 to 3 times that of a normal antireflection film.

  As a result, the product cost is doubled because the film thickness is about the same as that of the filter 2.

  In view of the above, an object of the present invention is to provide an optical component and a method for manufacturing the same that can reduce the manufacturing cost by making the manufacturing time as normal.

  Examples of the solving means of the present invention are as follows.

  (1) An optical component in which an antireflection film is deposited on one surface after a chemical strengthening treatment, and a filter film is deposited on the other surface.

  (2) In the optical component described above, the antireflection film has a multilayer structure, and the filter film has a multilayer structure.

  (3) In the optical component described above, the antireflection film has a structure of about three layers, and the filter film has a structure of about 30 layers.

  (4) A method for producing an optical component, characterized in that an antireflection film is deposited on one surface after a chemical strengthening treatment, and a filter film is deposited on the other surface.

  In the present invention, the “about three-layer structure” and the “about thirty-layer structure” are not limited to a multilayer structure that is strictly defined by three and thirty layers, respectively. Includes a multilayer structure close to the layer.

  According to the present invention, since the antireflection film is deposited after the chemical strengthening treatment, the film may be deposited using a deposition method using an ion process (IAD, RF-ion sputtering) or sputtering. The distortion of the optical component can be eliminated. In addition, it is not necessary to form a stress relieving layer (stress relieving layer) to the same thickness as the filter, and the manufacturing time can be made as usual, thereby reducing the product cost.

  In the present invention, an antireflection film is deposited after chemical strengthening treatment on one surface of the optical component, and a filter film is deposited on the other surface. Therefore, even if a film is formed using a film forming method such as vapor deposition (IAD, RF-ion sputtering) or sputtering using an ion process, the distortion of the optical component can be eliminated. Furthermore, it is not necessary to form a stress relaxation layer (stress relaxation layer) to the same thickness as the filter. In addition, the production time can be set as usual.

  The present invention is not limited only to the embodiment in which only one side of the optical component is chemically strengthened. For example, after both surfaces of the optical component are chemically strengthened, one side may be polished to leave stress only on the other side.

  The optical component according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1A, for example, a chemical strengthening process is performed on one surface 10a of the mirror 10. Thereafter, about 30 layers of the filter layer 11 are coated on the other surface 10b to obtain a multilayer structure of about 30 layers. The antireflection film 12 is also coated on the one surface 10a subjected to the chemical strengthening treatment. In this case, even if the antireflection film 12 provided on the one surface 10a subjected to the chemical strengthening treatment has only a multi-layer structure of about three layers, there is no sufficient distortion. There is no need to specially provide a stress relaxation layer (stress relaxation layer) as in the prior art to form a film with the same thickness as the filter. As a result, the manufacturing time may be a normal time, and the product cost can be suppressed.

  In this embodiment, a mirror is used as an example of an optical component. However, the present invention is not limited to this, and may be an optical component such as a wave plate, a polarizing plate, or a beam splitter.

  The glass chemical strengthening methods include air cooling strengthening and chemical strengthening. It is preferable that glass strengthening improves the properties of glass that is weak against tension by generating a compressive stress on the glass surface. For example, see the method described in paragraphs 0028 to 004 of Patent Document 2.

Regarding chemical strengthening, glass is immersed in potassium nitrate (KNO ₃ ) to replace Na ⁺ having a small ionic radius in the glass surface layer with K ⁺ having a larger ionic radius, and compressive stress is applied to the surface of the glass 20. Is generated.

  The characteristics of chemically tempered glass include that it can be tempered even when the glass is thin, that there is almost no deformation due to tempering, and that it can be tempered even with deformed or bent glass.

  Chemically tempered glass has excellent properties such as heat resistance, glass surface stress, static pressure load strength, and falling ball test strength.

Explanatory drawing which shows the manufacturing method of the optical component by one Example of this invention. A film forming method on a conventional wave plate will be described.

Explanation of symbols

1 Wave plate 2 Filter 3 Stress relaxation layer (stress relaxation layer)
DESCRIPTION OF SYMBOLS 10 Mirror 10a Mirror one surface 10b Mirror other surface 11 Filter layer 12 Antireflection film

Claims (4)

  An optical component, wherein an antireflection film is deposited on one surface after a chemical strengthening treatment, and a filter film is deposited on the other surface. The optical component according to claim 1,
The optical component, wherein the antireflection film has a multilayer structure, and the filter film has a multilayer structure. The optical component according to claim 1,
The optical component, wherein the antireflection film has a structure of about 3 layers, and the filter film has a structure of about 30 layers.   A method of manufacturing an optical component, comprising: depositing an antireflection film on one surface after chemical strengthening treatment and depositing a filter film on the other surface.

Images