JP2001002428A - Optical element molding die and method of manufacturing the same - Google Patents

Abstract

(57) [Problem] To use a plurality of split dies, prevent a glass material from flowing into a parting line without changing the surface property, and provide a mold for forming an optical element which does not adversely affect molding. It is to provide a manufacturing method. SOLUTION: In an optical element molding die composed of a plurality of split dies having a transfer surface for forming an optical element on a part of a base material, a transfer surface and a parting line of an adjacent split die are formed by a wet plating film. An optical element molding die in which a plating film is removed by etching only a transfer surface after coating, and a method of manufacturing the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for molding an optical element used for producing an optical element made of glass, such as a lens or a prism, with high precision by pressing a glass material, and a method for producing the same. More specifically, the present invention relates to a composite optical element molding die including a plurality of split dies and a method of manufacturing the same.

[0002]

2. Description of the Related Art The technology of manufacturing a lens by press molding a glass material without the need for a polishing step eliminates the complicated steps required in conventional manufacturing, making it possible to manufacture a lens simply and inexpensively. In recent years, it has been used in the manufacture of optical elements made of not only lenses but also prisms and other glasses.

Further, with the improvement and expansion of optical element molding techniques, the need for prisms having a plurality of free-form surfaces is increasing. Since molds corresponding to these optical elements do not allow a grinding tool to enter at the time of mold processing, it is necessary to use a plurality of divided molds and cover the parting line with a coating to prevent the inflow of glass material. No. 69422.

[0004] However, in the above-mentioned conventional split type, there is a problem that the transfer surface changes because the thickness of the coating is required to be 2 µm or more, and when the thickness is less than 2 µm, the film strength is insufficient. there were.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional problem. When a plurality of split molds are used, the surface of a glass material is not changed on the parting line without changing the surface properties. An object of the present invention is to provide an optical element molding die that prevents inflow and has no adverse effect upon molding, and a method for producing the same.

[0006]

According to the present invention, in a mold for forming an optical element comprising a plurality of split molds having a transfer surface for forming an optical element on a part of a base material, a transfer surface and a wet plating film are used. An optical element molding die is provided in which a plating film is removed by etching only a transfer surface after covering a parting line of an adjacent split mold.

Further, according to the present invention, in a method for manufacturing an optical element molding die comprising a plurality of split dies having a transfer surface for molding an optical element on a part of a base material, the transfer surface and the adjacent surface are formed by a wet plating film. There is provided a method for manufacturing an optical element molding die in which a plating film is removed by etching only a transfer surface after covering a parting line of a split mold.

[0008]

Embodiments of the present invention will be described below in detail.

According to the present invention, there is provided a molding die comprising a plurality of split dies having a transfer surface for forming an optical element on a part of a base material, wherein a wet plating film is used to form the transfer surface and an adjacent split mold parting line. Then, the plating film is removed by etching only the transfer surface.

Further, it is preferable to select an etching solution such that the etching rate of the material constituting the transfer surface of the base material is lower than the etching rate of the wet plating film, in order to maintain the accuracy of the transfer surface. desirable.

[0011] Materials of the base material include oxide ceramics mainly containing alumina and zirconia, silicon carbide, silicon nitride, titanium carbide, titanium nitride, carbide and nitride ceramics mainly containing tungsten carbide, and tungsten carbide. A cemented carbide mainly composed of molybdenum (Mo),
A metal containing tungsten (W) and tantalum (Ta) as main components, preferably a cemented carbide mainly containing tungsten carbide.

Further, in the case where the base material is a cemented carbide mainly composed of tungsten carbide, which cannot be precision-cut, a binary alloy of nickel (Ni) and phosphorus (P) and a carbide of the alloy are used as a working layer. A mixture with a nitride of the alloy, or a mixture with a carbonitride of the alloy, or nickel (Ni), copper (Cu) or tungsten (W),
A mixture of a ternary alloy of phosphorus (P) and a carbide of the alloy,
Alternatively, a mixture with a nitride of the alloy or a mixture with a carbonitride of the alloy is used.

As the wet plating film, one kind of metal selected from copper (Cu), cobalt (Co) and chromium (Cr) is used, and copper (Cu) is used as an etching solution.
A mixed solution of ethyl alcohol, chlorine and iron chloride, a mixed solution of methyl alcohol and nitric acid for cobalt (Co), and a mixed solution of distilled water and sulfuric acid for chromium (Cr). This is preferable because the etching rate is lower than the etching rate of the plating film and does not adversely affect the surface changes of the base material and the processed layer.

When the molding die is actually used for glass molding, in order to prevent fusion, after removing the plating film by etching only the transfer surface, the transfer surface is made of titanium, tantalum, chromium, or silicon. An intermediate layer of carbide, nitride, carbonitride is formed, and further thereon, a hard carbon film,
Or platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), osmium (Os), ruthenium (Ru), rhenium (Re), gold (Au), tungsten (W), tantalum (Ta) It is desirable to form a surface layer of at least one metal or alloy thin film selected from the group consisting of:

According to the optical element molding die having the above structure, since the parting line is covered with the wet plating film, the optical glass in a softened state does not flow into the parting line. In addition, the wet plating film is removed from the transfer surface by etching, and the surface of the base material and the processed layer does not change. And since the wet plating liquid has penetrated into the inside by the capillary phenomenon, sufficient strength can be ensured even when pressure molding is performed.

[0016]

The present invention will be described below in more detail with reference to specific examples.

(Example 1) FIG. 1 is a process chart of an optical element molding die of Example 1.

In the first step, the divided mold base materials 11, 12, and 13 respectively grind a cemented carbide mainly composed of WC into a desired approximate shape of a free-form surface.

In the second step, Ni-
Using a P target, processed layers 21, 22, and 23 of a mixed film of Ni-P and a carbide of Ni-P are formed to a thickness of 50 µm by sputtering film formation using argon and methane as an introduced gas.

In the third step, this processed layer is cut into a desired free-form surface by a diamond tool, and finished by uniform polishing.

In the fourth step, the split molds 11, 12, and 13 are combined to form a composite mold.

In the fifth step, a plating film 3 is formed to a thickness of 10 μm on the processed layer using a commercially available electroless copper plating solution (trade name: C-200LT, High Purity Chemical Laboratory Co., Ltd.). I do. At this time, the parting line is 2m deep from the surface
m of the plating film was formed.

In the sixth step, the plating film on the processed layer is removed by using a mixed solution of ethyl alcohol, hydrochloric acid and iron chloride as an etching solution.

In a seventh step, an intermediate layer 4 of a TiN film is formed to a thickness of 0.5 μm on the processed layers 21, 22 and 23 from which the plating film has been removed by an ion plating method.

In an eighth step, a surface layer 5 of a hard carbon film is formed on the intermediate layer 4 to a thickness of 100 nm by ion beam evaporation.

When this mold was subjected to glass molding (phosphate-based glass) using a continuous molding machine, a good molded product was obtained even after 3000 shot molding, and deterioration of the mold material surface and parting line was also observed. Was not done.

(Example 2) The second step was omitted, and the third step was performed in the same manner as in Example 1 except that the base material was directly ground.
An optical element mold was obtained.

When this mold was subjected to glass molding (phosphate-based glass) using a continuous molding machine, a good molded product was obtained even after 3000 shot molding, and deterioration of the mold material surface and parting line was also observed. Was not done.

(Example 3) An optical element molding die was obtained in the same manner as in Example 1 except that the fifth and sixth steps were changed as follows.

In the fifth step, a commercially available electrolytic cobalt plating solution (trade name: COM03LA, Kojundo Chemical Laboratory Co., Ltd.)
Is used to form a plating film 3 to a thickness of 10 μm on the processing layer. At this time, a plating film having a depth of 1.8 mm from the surface was formed on the parting line.

In the sixth step, the plating film on the working layer is removed by using a mixed solution of distilled water and hydrochloric acid as an etching solution.

When this mold was subjected to glass molding (phosphate-based glass) using a continuous molding machine, a good molded product was obtained even after 3000 shot molding, and deterioration of the mold material surface and parting line was also observed. Was not done.

Example 4 An optical element molding die was obtained in the same manner as in Example 1 except that the fifth and sixth steps were changed as follows.

The fifth step comprises chromic anhydride as a main component,
Using a small amount of sulfuric acid, electrolytic chromium plating film 3
Is formed to a thickness of 10 μm. At this time, a plating film having a depth of 1.7 mm was formed on the parting line from the surface.

In the sixth step, a mixed solution of distilled water and sulfuric acid is boiled as an etching solution to remove the plating film on the processed layer.

When this mold was subjected to glass molding (phosphate glass) using a continuous molding machine, a good molded product was obtained even after 3000 shot molding, and deterioration of the mold material surface and parting line was also observed. Was not done.

(Embodiment 5) In the second step, Ni-P and Ni
Instead of a mixed film with -P carbide, Ni-P and Ni-
Mixed film with P nitride, mixed film with Ni-P and Ni-P carbonitride, mixed film with Ni-P-Cu and Ni-P-Cu carbide, Ni-P-Cu and Ni A mixed film of -P-Cu nitride, a mixed film of Ni-P-Cu and Ni-P-Cu carbonitride, a mixed film of Ni-P-W and Ni-P-W carbide, Except for changing to a mixed film of Ni-P-W and Ni-P-W nitride and a mixed film of Ni-P-W and Ni-P-W carbonitride, the same as in Example 1 Thus, an optical element molding die was obtained.

When this mold was subjected to glass molding (phosphate-based glass) using a continuous molding machine, a good molded product was obtained even after 3000 shot molding, and deterioration of the mold material surface and parting line was also observed. Was not done.

(Embodiment 6) TiN of the intermediate layer in the seventh step
The film is made of TiC, TiCN, TaN, TaC, TaCN, S
An optical element mold was obtained in the same manner as in Example 1 except that iC, SiN, SiCN, CrN, CrC, and CrCN were changed.

When this mold was subjected to glass molding (phosphate glass) using a continuous molding machine, no deterioration of the parting line was observed even after 3000 shot molding.

(Embodiment 7) In the eighth step, the hard carbon film of the surface layer was formed of platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), osmium (Os), ruthenium (Ru), An optical element molding die was obtained in the same manner as in Example 1, except that at least one metal or alloy thin film selected from rhenium (Re), gold (Au), tungsten (W), and tantalum (Ta) was formed.

When this mold was subjected to glass molding (phosphate glass) using a continuous molding machine, no deterioration of the parting line was observed even after 3000 shot molding.

(Comparative Example 1) The fifth and sixth steps were omitted, and the seventh
Example 1 except that the thickness of the TiN film in the step was 3 μm.
An optical element mold was obtained in the same manner as described above, but the surface shape with the desired accuracy could not be obtained.

When this mold was subjected to glass molding (phosphate-based glass) using a continuous molding machine, cracks were observed in the parting line after 300 shots were molded.

[0045]

As described above, according to the mold for molding an optical element of the present invention, the parting line is covered with the wet plating film, so that the optical glass in a softened state is formed inside the parting line. And the transfer surface has the wet plating film removed by etching,
Since the base material and the processed layer did not change in surface, a good molded product was obtained. Since the wet plating solution penetrated into the interior due to the capillary phenomenon, sufficient strength could be ensured even when the pressure was repeatedly molded, so that the deterioration of the parting line was not observed.

[Brief description of the drawings]

FIG. 1 is a schematic view of a manufacturing process of an optical element molding die of the present invention. (A) First step: grinding processing (b) Second step: formation of a working layer (c) Third step: cutting and uniform polishing (d) Fourth step: configuration of a composite mold (e) Fifth step: Formation of plating film (f) Sixth step: removal of plating film (g) Seventh step: formation of intermediate layer (h) Eighth step: formation of surface layer

[Explanation of symbols]

 11, 12, 13 Split mold base material 21, 22, 23 Working layer 3 Plating film 4 Intermediate layer 5 Surface layer

Claims (10)

[Claims] 1. An optical element molding die comprising a plurality of split dies having a transfer surface for forming an optical element on a part of a base material, wherein a transfer surface is formed by a wet plating film and a parting line of an adjacent split die. Wherein the plating film is removed by etching only the transfer surface after coating. 2. The optical element molding die according to claim 1, wherein an etching rate of a material forming the transfer surface of the base material is lower than an etching rate of the wet plating film. 3. The base material is a cemented carbide having tungsten carbide as a main component, and the wet plating film is one kind of metal selected from copper (Cu), cobalt (Co) and chromium (Cr). The mold for molding an optical element according to claim 1. 4. A mold for forming an optical element comprising a plurality of split molds having a transfer surface for forming an optical element on a part of a base material, wherein the base material is a cemented carbide mainly composed of tungsten carbide. And a mixture of a binary alloy of nickel (Ni) and phosphorus (P) with a carbide of the alloy, a mixture of the alloy with a nitride thereof, or a mixture of the alloy with a carbonitride of the alloy Or a mixture of a ternary alloy of nickel (Ni), copper (Cu) or tungsten (W), and phosphorus (P) and a carbide of the alloy, or a mixture of a nitride of the alloy, or a mixture of the alloys. A processed layer of a mixture with carbonitride is processed into a desired shape, and a wet-processed layer formed of one type of metal selected from copper (Cu), cobalt (Co), and chromium (Cr) is formed thereon. After coating the plating film, only the transfer surface is etched An optical element molding die, wherein a plating film is removed by the method. 5. In an optical element molding die comprising a plurality of split dies having a transfer surface for forming an optical element on a part of a base material, after removing a plating film by etching only the transfer surface, the transfer is performed. On the surface, an intermediate layer of carbide, nitride, carbonitride made of titanium, tantalum, chromium, silicon is formed, and further, a hard carbon film or platinum (Pt),
Palladium (Pd), iridium (Ir), rhodium (Rh), osmium (Os), ruthenium (Ru),
Rhenium (Re), gold (Au), tungsten (W),
An optical element molding die, wherein a surface layer of at least one metal or alloy thin film selected from tantalum (Ta) is formed. 6. A method for manufacturing an optical element molding die comprising a plurality of split dies having a transfer surface for forming an optical element on a part of a base material, wherein the transfer surface and an adjacent split die are formed by a wet plating film. A method of manufacturing a mold for forming an optical element, comprising: after coating a parting line, removing a plating film by etching only the transfer surface. 7. The method of manufacturing an optical element molding die according to claim 6, wherein an etching solution is used such that an etching rate of a material forming a transfer surface of the base material is lower than an etching rate of a wet plating film. 8. The base material is a cemented carbide mainly composed of tungsten carbide, and one kind of metal selected from copper (Cu), cobalt (Co) and chromium (Cr) is used for a wet plating film. A method for manufacturing the optical element molding die according to claim 6. 9. A method for manufacturing an optical element molding die comprising a plurality of split molds having a transfer surface for molding an optical element on a part of a base material, wherein the base material mainly comprises tungsten carbide. This is a cemented carbide, with nickel (N
i) a mixture of a binary alloy of phosphorus (P) and a carbide of the alloy, or a mixture of a nitride of the alloy, or a mixture of a carbonitride of the alloy, or nickel (Ni) and copper ( A working layer of a mixture of Cu) or tungsten (W) and a ternary alloy of phosphorus (P) and a carbide of the alloy, a mixture of a nitride of the alloy, or a mixture of a carbonitride of the alloy, Is processed into a desired shape, and a wet plating film formed of one kind of metal selected from copper (Cu), cobalt (Co) and chromium (Cr) is coated thereon, and then the transfer surface is formed. A method of manufacturing an optical element molding die, comprising removing a plating film by etching only. 10. A method of manufacturing an optical element molding die comprising a plurality of split dies having a transfer surface for molding an optical element on a part of a base material, wherein a plating film is removed by etching only the transfer surface. An intermediate layer of a carbide, nitride, or carbonitride made of titanium, tantalum, chromium, or silicon is formed on the transfer surface, and a hard carbon film or platinum (Pt) or palladium (Pd) is further formed thereon. , Iridium (I
r) Surface of at least one metal or alloy thin film selected from rhodium (Rh), osmium (Os), ruthenium (Ru), rhenium (Re), gold (Au), tungsten (W), and tantalum (Ta) A method for producing an optical element molding die, comprising forming a layer.