JPH03242333A - Manufacture of mold for press-molding optical element and production of optical element - Google Patents

Abstract

PURPOSE:To provide a mold capable of producing optical elements having good reproducibility and durability attaching a desired shape thin film to the surface of a mold prepared by coating the surface of a base material comprising a specified cemented carbide with a specific alloy and subsequently ethcing the attached thin film. CONSTITUTION:A thin film formed into a desired shape is attached to the surface of a mold prepared by coating the surface of a base material comprising a cemented carbide containing WC as a main component or comprising a cermet containing TiN, TiC, Cr3C2 or Al2O3 as a main component with an alloy containing at least one metal selected from Pt, Pd, Ir, Rh, Os, Ru, Re, W and Ta, and the mold is physically or chemically etched in the isotropic direction from the above-mentioned surface to provide a mold in which the alloy thin film containing at least one metal selected from the Pt, Pd, Ir, Rh, Os, Ru, Re, W and Ta coated on the surface of the mold is formed into a desired shape and which is useful for press-molding optical elements.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a press molding die for producing microfabricated high-precision optical elements in large quantities and at low cost, and a method for manufacturing the optical elements. It is.

Conventional technology Conventionally, as a method for manufacturing high-precision optical elements such as diffraction gratings, a metal such as aluminum (AI) was deposited directly on a flat glass plate using a high-precision ruling engine. There is a method of forming grooves at equal intervals by pressing a diamond tool on the surface, and rNIKKEI
Gate ECHA-NICAL.

1985.6.17. As shown on p. 85,
There is a method of forming other renosts on a line at equal intervals on the resist and physically etching it to process the resist into a sawtooth shape, or as shown in Japanese Patent Application No. 62-331972. A method is being considered in which a reflective holographic ink diffraction grating is produced by forming a photoresist resin into a diffraction grating shape through holographic exposure and, after development, depositing a metal such as aluminum on the resin.

Problems to be Solved by the Invention However, conventional methods require a very long time to manufacture one optical element. Furthermore, it was difficult to produce high-precision products in large quantities, and there were problems with reproducibility. There was also a problem with the durability of the manufactured optical element.

In view of the above problems, the present invention forms a desired shape on the surface of a high-strength mold material using a physical or chemical method, and press-forms glass using the mold. The aim is to produce optical elements made of glass that have good reproducibility and good durability.

Means for Solving the Problems In order to solve the above problems, the present invention uses cemented carbide whose main component is WC, TiNTiC, Cr3C2 as the base material.
Alternatively, using a cermet whose main component is Al2O2,
PtPd Ir Rh Os on the surface of the base material,
A thin film formed in a desired shape is attached to the surface of a mold coated with an alloy thin film containing at least one metal among Ru, Re, W, and Ta, and is physically or chemically applied in the same direction from the surface. Etching is performed to remove Pt, Pd, Ir, Rh, Os, Ru, and Re on the mold surface.

By press-molding glass using an optical element press-molding mold in which a desired shape is formed on an alloy thin film containing at least one type of metal among WTa, it is possible to achieve good reproducibility (and durability). This makes it possible to manufacture optical elements in large quantities and at low cost.

Effect The present invention makes it possible to easily produce a high-precision, high-strength press molding mold by the method described above, and furthermore, by press-molding glass using the mold, a highly durable press molding mold can be produced. , it has become possible to produce highly accurate optical elements with good reproducibility, in large quantities, and at low cost.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

Example 1 First, a cermet mainly composed of titanium nitride (TiN) with a diameter of 20 cm and a thickness of 6 cm was used as a base material, and the surface of the base material was polished using ultrafine diamond abrasive grains.
Polished to a mirror surface.

Next, an Ir-Ru-Ta alloy thin film with a thickness of about 5 μm was coated as a protective film on the mirror-finished surface of the base material by sputtering to produce a planar unprocessed press molding die. . The cross-sectional structure of the unprocessed press molding die is shown in the first part. In FIG. 1, 11 is a base material, and 12 is a protective film.

Next, an aluminum film was deposited on the surface of a flat glass using a coating method, and the surface was mechanically processed using a ruling engine to form a diffraction grating with a sawtooth cross-sectional shape with a pinch of 1 μm and a step of 1 μm. Figure 2 shows a cross-sectional structural diagram of the diffraction grating.
21 is a flat glass, and 22 is an aluminum film.

After applying a mold release agent to the surface of the diffraction grating, an aluminum film was again formed thereon by vapor deposition. Further, a thermosetting resin was applied thereon, an extremely thin flat glass plate was placed on top of it, the whole was heated to harden the resin, and then the glass flat plate was separated from the diffraction grating. In this way, a resin film having the inverted shape of the diffraction grating was formed on the glass flat plate. FIG. 3 shows a cross-sectional structural diagram of the glass substrate. In FIG. 3, 31 is a glass flat plate, and 32 is a thermosetting resin film having an inverted diffraction grating shape.

Subsequently, the glass substrate shown in FIG. 3 was attached to the surface of the unprocessed press molding die shown in FIG. 1 with an adhesive. A cross-sectional structural diagram of this state is shown in FIG. In FIG. 4, 41 is a base material, 42 is a protective film, 43 is an adhesive, and 44
45 is a glass flat plate, and 45 is a thermosetting resin film having an inverted diffraction grating shape.

The mold in the state shown in Fig. 4 was set in the ECR (child cyclotron resonance) plasma ion shower etching device shown in Fig. 5, and the entire surface was uniformly etched with Ar gas, and an inverted shape of the diffraction grating was formed on the protective film. Enching ended when the image was transcribed. In FIG. 5, 51 is an ECR plasma generator, 52 is an ion extraction electrode,
53 is a shutter, 54 is a substrate holder, and 55 is an exhaust device.

A cross-sectional view of the mold thus produced is shown in FIG.

In FIG. 6, 61 is a base material, and 62 is a protective film. In the mold produced in this way, only the surface of the protective film on the surface of the base material is processed, so it is possible to create a press-molding mold for diffraction gratings with extremely high strength and excellent durability. Recognize.

In Example 1, a diffraction grating was used as an optical glass element, and a method for manufacturing a press-molding mold for the diffraction grating was explained. Needless to say, a mold for press-molding a finely shaped object such as a substrate can be easily manufactured by the same method described in Example 1.

In addition, in Example 1, Ti was used as the mold material in the base material.
A cermet whose main component is N is used, and Ir is used as a protective film.
-Ru-Ta alloy sputtered film was used, but the base material is a cemented carbide whose main component is WC or T i C, Cr a
A cermet whose main component is C2 or AN203 is used, and P(Pd Ir Rh, Os
, Ru, Re, W, and Ta, a press molding die with good durability can be similarly produced using an alloy thin film containing at least one metal among the following.

Example 2 An example of a method for producing a diffraction grating on a glass surface using the mold produced as described above will be described.

The diffraction grating mold shown in FIG. 6 prepared in Example 1 was used as the upper mold, and a flat mold made of TiN cermet as a base material polished into a flat surface and coated with an Ir-RuTa alloy sputtered film as a protective film was used. A lower mold is formed and placed in a press molding machine shown in FIG. In Fig. 7, 71 is a fixed plotter for the upper mold, 72 is a heater for the upper mold, 73 is the upper mold, 74 is a flat glass, 75 is the lower mold, 76 is a heating heater for the lower mold, and 77 is a fixed heater for the lower mold. block, 78 is a thermocouple for the upper mold, 79 is a thermocouple for the lower mold, 710 is a plunger, 71
1, a positioning sensor 712 is a stopper, and 713 is a cover.

First, 70% by weight of lead oxide (PbO), silica (Sin)
A disk-shaped flat glass 74 with a radius of 10 m and a thickness of 2 m, consisting of 27% by weight and the rest being trace components, was placed on a lower mold 75, an upper mold 73 was placed on top of it, and the temperature was raised to 520°C. , 2 at a press pressure of approximately 40 kg/cd in a nitrogen atmosphere.
Pressed for a minute.

Thereafter, the upper and lower molds are cooled to 300° C. in that state, and the press-molded glass diffraction grating is taken out from the molds to complete the molding process.

After repeating the above steps, at the end of the 10,000th press, take out the upper die 73 from the press molding machine, observe the condition of the press surface with an optical microscope V and mirror, and check the surface roughness of the press surface (RMS value, human ) was measured to evaluate mold accuracy.

The results of the press test are shown in Table 1. Specimen Hidden 1 to 5
The molds produced by the method of the present invention up to 10,000
Even after repeated pressing, the surface roughness (RMS value) was almost the same as the surface roughness before pressing, and no change in shape was observed.

Furthermore, the diffraction efficiency of all molded glass diffraction gratings was 90% or higher.

Table 1 Press test results As shown in Example 1 and Example 2, the method of the present invention makes it possible to produce a highly durable press mold for micro-shaped optical elements. By press-molding using this mold, it has become possible to manufacture high-precision optical elements in large quantities with good reproducibility.

Effects of the Invention The method of the present invention makes it possible to easily perform microfabrication on a mold material that has extremely high strength and good durability, making it possible to easily obtain a press molding mold for high-precision optical elements. Became. Furthermore, by press-molding glass using the mold thus produced, it has become possible to produce optical elements with high accuracy, durability, and high reliability in large quantities with good reproducibility.

[Brief explanation of drawings]

Figure 1 is a cross-sectional structural diagram of the planar mold before processing, Figure 2 is a cross-sectional structural diagram of the diffraction grating fabricated by machining, and Figure 3 is a diagram of the diffraction grating shape shown in Part 2 transferred onto the resin. FIG. 4 is a cross-sectional view of the replica immediately before dry etching according to the method of the present invention, and FIG. 5 is a cross-sectional view of the replica used in Example 1.
Schematic diagram of CR plasma ion shower enoting device,
FIG. 6 is a cross-sectional structural diagram of a press molding die for a diffraction grating produced by the method of the present invention, and FIG. 7 is a schematic diagram of a press molding machine used in Example 2. 11... Base material, 12... Protective film.

Claims (2)

[Claims] (1) The base material is a cemented carbide whose main component is tungsten carbide (WC) or titanium nitride (TiN).
, titanium car hard (TiC), chrome car hard (C
Using a cermet whose main component is r_3C_2) or alumina (Al_2O_3), platinum (Pt), palladium (Pd), iridium (Ir),
Rhodium (Rh), Osmium (Os), Ruthenium (
A thin film formed into a desired shape is attached to the surface of a mold coated with an alloy thin film containing at least one metal among Ru), rhenium (Re), tungsten (W), and tantalum (Ta). By performing physical or chemical etching in a more iso-directional manner, the Pt on the mold surface,
Production of a press-molding mold for an optical element characterized by forming a desired shape into an alloy thin film containing at least one metal among Pd, Ir, Rh, Os, Ru, Re, W, and Ta. Method. (2) The base material is a cemented carbide whose main component is WC or Ti.
A cermet whose main components are N, TiC, Cr_3C_2 or Al_2O_3 is used, and Pt is applied to the surface of the base material.
, Pd, Ir, Rh, Os, Ru, Re, W, and Ta, a thin film formed in a desired shape is attached to the surface of the mold coated with an alloy thin film containing at least one metal among the following. Perform physical or chemical etching in the same direction to remove Pt, Pd, Ir, Rh on the mold surface.
, Os, Ru, Re, W, and Ta, an alloy thin film containing at least one metal selected from among them is press-molded using a press-molding die for optical elements in which a desired shape is formed. Method of manufacturing element.