JP2010181514A - Optical component and protective member for laser beam machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical member for infrared whose transmittance is high and whose environmental resistance is excellent. <P>SOLUTION: The optical member 1 comprises a substrate 2 and an infrared antireflection film 3. The substrate 2 comprises one of ZnSe, ZnS and GaAs. The infrared antireflection film 3 is formed on at least one surface of the substrate 2 and formed of layered product by laminating an inner layer 4, an intermediate layer 5 and an outer layer 6 in this order from the substrate side. The inner layer 4 comprises a fluoride film, the intermediate layer 5 comprises one of a ZnSe film, a ZnS film and GaAs film and the outer layer 6 comprises a diamond like carbon (DLC) film. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical component and a protection member for a laser beam machine.

  In recent years, optical devices using infrared light have been actively developed, and in particular, the use of infrared light in the 8 to 14 μm region has attracted attention. Along with this, various infrared optical components effective for infrared light in this region have been proposed. Of such infrared optical components, as an optical component having the function of an infrared antireflection film, an infrared transmission member such as ZnSe, ZnS, GaAs, Ge, or the like is used as a base material (substrate), and fluoride is formed on the base material. A structure in which a film of ZnSe, ZnS, GaAs, Ge, or the like is formed is known (see, for example, Patent Document 1).

  The optical component described in Patent Document 1 has low infrared absorption and high environmental resistance, but the strength of the thin film formed on the substrate surface is sufficient. Therefore, it is not suitable for use outdoors or in laser processing machines that are in harsh environments such as scattered workpieces.

  On the other hand, an optical component for a laser processing machine is known in which a diamond-like carbon film (DLC film) is directly formed on the surface of a base material (a surface on which a laser beam is emitted and faces a workpiece). (For example, refer to Patent Document 2).

Japanese Patent No. 3355786 Patent No. 4074217

  The DLC film used in the optical component described in Patent Document 2 has high hardness and is suitable for use in the environment described above, but a general infrared transmitting member (ZnSe, ZnS, GaAs) used as a base material. Etc.) and the refractive index is the same, it is necessary to increase the thickness of the DLC film in order to increase the infrared transmittance. In this case, since the compressive residual stress of the DLC film is increased and the adhesiveness is lowered, it is necessary to use a material having a high refractive index as the base material. Ge is an example of such a high refractive index material, but when Ge is used, high transmittance cannot be obtained. Moreover, since Ge has a high absorption rate, there is a problem that it is not suitable for high power laser applications.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an infrared optical component having a high transmittance and excellent environmental resistance, and a protective member for a laser beam machine.

The optical component of the present invention is an optical component comprising a substrate and an infrared antireflection film,
The substrate is made of any one of ZnSe, ZnS and GaAs,
The infrared antireflection film is formed on at least one surface of the substrate, and from the substrate side, is composed of a laminate in which an inner layer, an intermediate layer, and an outer layer are laminated in this order,
The inner layer is made of a fluoride film,
The intermediate layer is made of any one of a ZnSe film, a ZnS film, and a GaAs film, and
The outer layer is made of a DLC film.

  In the optical component of the present invention, an intermediate layer made of any one of a ZnSe film, a ZnS film and a GaAs film and an inner layer made of a fluoride film are provided as a lower layer of the DLC film which is an outer layer. However, high transmittance can be maintained.

  The DLC film preferably has a thickness of 150 to 300 nm. The DLC film has high hardness and excellent environmental resistance, but on the other hand, it has compressive stress, so that it is necessary to relax the stress difference from the fluoride film having tensile stress as much as possible. In order to improve the environmental resistance performance, it is preferably thicker than 150 nm, and in order to relax the stress difference, it is preferable to make it thinner than 300 nm. Moreover, since the transmittance decreases as the DLC film becomes thicker, it is preferable to make it thinner than 300 nm from the viewpoint of keeping the transmittance high.

  The thickness of the fluoride film is preferably 400 to 600 nm. As the film thickness of the fluoride film increases, the absorptance increases and it becomes difficult to satisfy the absorptivity required for high power laser applications. On the other hand, if the film thickness is too small, a sufficient antireflection layer cannot be formed with other layers. Therefore, in order to satisfy both, the film thickness is preferably in the range of 400 to 600 nm.

  The intermediate layer preferably has a thickness of 400 to 600 nm. In the case of the intermediate layer, the film thickness is preferably in the range of 400 to 600 nm for the same reason as the fluoride film.

The fluoride film is preferably made of YF ₃ or YbF ₃ . Since the film made of YF ₃ or YbF ₃ has a high transmittance, the transmittance of the entire film can be increased.

Further, the protective member of the laser beam machine of the present invention (hereinafter also simply referred to as “protective member”) is a lens protective member of a laser beam machine having a substrate and an infrared antireflection film,
The substrate is made of any one of ZnSe, ZnS and GaAs,
The infrared antireflection film is formed on at least the emission side of the laser processing machine of the substrate, and from the substrate side, is composed of a laminate in which an inner layer, an intermediate layer, and an outer layer are laminated in this order,
The inner layer is made of a fluoride film,
The intermediate layer is made of any one of a ZnSe film, a ZnS film, and a GaAs film, and
The outer layer is made of a DLC film.

  In the protective member of the present invention, as the lower layer of the DLC film which is the outer layer, an intermediate layer made of any of a ZnSe film, a ZnS film and a GaAs film and an inner layer made of a fluoride film are provided. However, high transmittance can be maintained. Therefore, it is suitable for a protective member of a laser beam machine in a harsh environment such as when a workpiece is scattered.

  According to the optical component of the present invention and the protection member for a laser beam machine, the transmittance can be increased and the environmental resistance can be improved.

It is sectional explanatory drawing of one Embodiment of the optical component of this invention. It is sectional explanatory drawing of the infrared laser processing machine using the protection member of this invention.

  Hereinafter, embodiments of an optical component and a protection member of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional explanatory view of an optical component 1 according to an embodiment of the present invention. This optical component 1 has a configuration in which infrared antireflection films 3 are formed on both surfaces of an infrared optical substrate 2. I have. The infrared optical substrate 2 is made of any one of ZnSe, ZnS, and GaAs (infrared transmitting member) having a thickness of about 1 to 10 mm. Of these, from the viewpoint of obtaining a higher infrared transmittance, ZnSe and It is preferable to use a substrate made of ZnS. In the embodiment shown in FIG. 1, the infrared antireflection film 3 is formed on both surfaces of the infrared optical substrate 2, but the infrared antireflection film 3 may be formed only on one surface of the substrate. it can.

  The infrared prevention reflective film 3 includes, from the infrared optical substrate 2 side, a lower refractive index inner layer 4, an intermediate refractive index intermediate layer 5 having a higher refractive index than the inner layer 4, and the intermediate layer 5. The outer layer 6 having a high refractive index and a high refractive index is composed of a laminated body laminated in this order.

The inner layer 4 is made of a fluoride film such as a YF ₃ film, a YbF ₃ film, or an MgF ₂ film. Among these, the YF ₃ film is large in that the transmittance is large and the transmittance of the entire film can be increased. Alternatively, it is preferably made of a YbF ₃ film. The thickness of the inner layer 4 is selected in consideration of the thickness of the substrate and the thickness of the other layers, but is generally about 50 to 1000 nm, and preferably 400 to 600 nm. As the film thickness of the fluoride film increases, the absorptance increases and it becomes difficult to satisfy the absorptivity required for high power laser applications. On the other hand, if the film thickness becomes too small, the effect of the multilayer antireflection film for infrared light cannot be obtained. Therefore, in order to satisfy both, the film thickness is preferably in the range of 400 to 600 nm.

  The intermediate layer 5 is composed of any one of a ZnSe film, a ZnS film, and a GaAs film, and the thickness thereof is selected in consideration of the substrate thickness and the thickness of the other layers, and is approximately 50 to 1000 nm, preferably Similar to the inner layer 4, the thickness is 400 to 600 nm. As the film thickness of the ZnSe film constituting the intermediate layer 5 increases, the absorptance increases and it becomes difficult to satisfy the absorptivity required for high power laser applications. On the other hand, if the film thickness becomes too small, the effect of the multilayer antireflection film for infrared light cannot be obtained. Therefore, in order to satisfy both, the film thickness is preferably in the range of 400 to 600 nm.

  The outer layer 6 is made of a DLC (diamond-like carbon) film, and the thickness thereof is not particularly limited in the present invention, but is generally about 100 to 1500 nm, of which 150 to 300 nm. preferable. Although the DLC film has high hardness and excellent environmental resistance, on the other hand, it has compressive stress. Therefore, it is necessary to relax the stress difference with the fluoride film (inner layer 4) having tensile stress as much as possible. In order to improve the environmental resistance performance, it is preferably thicker than 150 nm, and in order to relax the stress difference, it is preferable to make it thinner than 300 nm. Moreover, since the transmittance decreases as the DLC film becomes thicker, it is preferable to make it thinner than 300 nm from the viewpoint of keeping the transmittance high.

  As a method of forming each film constituting the infrared preventing reflection film 3, a conventionally known vacuum thin film deposition technique such as a vacuum deposition method or an ion plating method can be used. The thickness of each film can be determined using, for example, commercially available film design software.

  FIG. 2 is a cross-sectional explanatory view of an infrared laser beam machine using the protective member of the present invention. In FIG. 2, reference numeral 20 denotes a laser oscillator disposed to face a workpiece 30 such as a printed wiring board. Between the laser oscillator 20 and the workpiece 30, a condenser lens 40 and the protection member 11 are provided. Has been placed. A carbon dioxide laser with a wavelength of 10.6 μm is used as the laser beam 50 emitted from the lens oscillator 20, and a single lens made of ZnSe is used as the condenser lens 40.

  The protection member 11 transmits the laser beam 50 and protects the condenser lens 40 from dust generation, contamination caused by sputtering, and damage generated during laser processing. The infrared optical substrate 12 and the infrared optical substrate And an infrared antireflection film 13 formed on the emission side of the laser processing machine of the substrate 12 for use. Further, the infrared prevention reflective film 13 includes, from the infrared optical substrate 12 side, a low refractive index inner layer 14, an intermediate refractive index intermediate layer 15 having a higher refractive index than the inner layer 14, and the intermediate layer 15. Also, the outer layer 16 having a high refractive index and a high refractive index is composed of a laminated body in this order. The materials and thicknesses of the infrared optical substrate 12, inner layer 14, intermediate layer 15 and outer layer 16 are the same as those of the infrared optical substrate 2, inner layer 4, intermediate layer 5 and outer layer 6 in the optical component 1 described above. Therefore, detailed description is omitted.

  Next, the optical component of the present invention will be described based on examples, but the present invention is not limited to such examples.

[Example 1]
Optical components that require high transmittance and environmental resistance in the infrared wide area were fabricated. As shown in FIG. 1, the optical component has a configuration in which an infrared antireflection film is formed on each side of the substrate.
The low refractive index first layer (inner layer), intermediate refractive index second layer (intermediate layer) and high refractive index third layer (outer layer) shown in Table 1 are vacuumed from the side of the 3 mm thick ZnSe substrate. It formed by the vapor deposition method. The center wavelength λ was 9.3 μm, and the thickness of each layer was determined by using a commercially available film design software (TFCalC of Software Spectra, Inc.).

[Comparative Example 1]
A DLC film having a thickness of 1 μm was formed on both sides of a Ge substrate having a thickness of 3 mm by vacuum deposition.

[Comparative Example 2]
An optical component was manufactured in the same manner as in Example 1 except that the DLC film as the third layer was not formed.

The infrared wavelength transmittance and environmental resistance performance of the optical parts obtained in Example 1 and Comparative Examples 1 and 2 were examined. The environmental resistance was tested by the same method as below. The results are shown in Table 2.
Abrasion resistance test: Observe whether the anti-reflection coating is peeled off by polishing with a polishing apparatus for 30 seconds.
Scratch test: Scratch the infrared reflective film with a commercially available ballpoint pen and observe the peeling of the infrared reflective film.

  As can be seen from Table 2, the optical component of Example 1 has a high transmittance, and there is no film abrasion due to polishing or film peeling due to scratching, and excellent environmental resistance performance. On the other hand, the optical component of Comparative Example 1 is excellent in environmental resistance, but has a low transmittance of 95% or less. Further, the optical component of Comparative Example 2 had a high transmittance of 99% or more, but was inferior in environmental resistance due to wear and peeling.

  It should be noted that the embodiment disclosed this time is merely an example in all respects and is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Optical component 2 Infrared optical board | substrate 3 Infrared antireflection film 4 Inner layer 5 Intermediate layer 6 Outer layer 11 Protective member 12 Infrared optical substrate 13 Infrared antireflection film 14 Inner layer 15 Intermediate layer 16 Outer layer 20 Laser oscillator 30 Processed Object 40 Condenser lens 50 Laser light

Claims (6)

An optical component comprising a substrate and an infrared antireflection film,
The substrate is made of any one of ZnSe, ZnS and GaAs,
The infrared antireflection film is formed on at least one surface of the substrate, and from the substrate side, is composed of a laminate in which an inner layer, an intermediate layer, and an outer layer are laminated in this order,
The inner layer is made of a fluoride film,
The intermediate layer is made of any one of a ZnSe film, a ZnS film, and a GaAs film, and
The optical component, wherein the outer layer is made of a DLC film.   The optical component according to claim 1, wherein the DLC film has a thickness of 150 to 300 nm.   The optical component according to claim 1, wherein the fluoride film has a thickness of 400 to 600 nm.   The optical component according to claim 1, wherein the intermediate layer has a thickness of 400 to 600 nm. The optical component according to claim 1, wherein the fluoride film is made of YF ₃ or YbF ₃ . A protective member for a laser processing machine having a substrate and an infrared antireflection film,
The substrate is made of any one of ZnSe, ZnS and GaAs,
The infrared antireflection film is formed on at least the emission side of the laser processing machine of the substrate, and from the substrate side, is composed of a laminate in which an inner layer, an intermediate layer, and an outer layer are laminated in this order,
The inner layer is made of a fluoride film,
The intermediate layer is made of any one of a ZnSe film, a ZnS film, and a GaAs film, and
A protective member for a laser beam machine, wherein the outer layer is made of a DLC film.

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