WO2021172682A1 - Mold for forming glass lens and manufacturing method of same - Google Patents

Abstract

Disclosed is a mold for forming a glass lens, the mold having a surface that comes in contact with a glass lens being formed is coated with a coating layer comprising a ta-C layer doped with 3 at% to 20 at% of Si. The mold for forming a glass lens provided according to one aspect of the present invention enables successful production of the glass lens without causing issues such as carbonization even in a high-temperature glass lens forming process, and due to excellent releasability and durability, can maximize the lifetime of the mold and lens manufacturing efficiency. Further, the present invention enables a rapid removal of the coating layer by means of oxygen etching, and thus, in case of the occurrence of a defect in the coating layer, can perform re-coating by only removing the coating layer by means of oxygen etching without a high-cost, time-consuming mold reprocessing process, thereby significantly reducing the cost and time required for mold reprocessing.

Description

Glass lens molding mold and method for manufacturing the same

The present invention relates to a mold for forming a glass lens and a method for manufacturing the same.

In the conventional mold coating technology for lens molding, a coating of noble metals (Ir, Re), etc. or a general a-C:H structure DLC coating has been applied according to the low-temperature lens molding process. In addition, the application of ta-C (tetrahedral amorphous carbon) has been made recently. However, as the scope of use of the lens is widened, as it begins to be exposed to a harsh use environment, high durability of the lens itself is required, and accordingly, the lens material is being changed to a material that requires high temperature molding.

The demand for high-temperature molded glass lenses used in recognition/sensing sensors such as lidar systems has increased, and as the demand for lightweight laser light sources increases due to the high price and large volume of existing laser light source equipment, high gains in the wavelength range A glass lens with In addition, as these glass lenses are used in products that are frequently exposed to external environments such as CCTV, the material needs to be changed to ensure durability of the lens.

From this point of view, when the coatings of the existing mold are applied to a process in which molding is performed at a high temperature (650° C. or higher), it is difficult to use because the film removal phenomenon or abrasion resistance decrease due to lack of heat resistance is remarkable. Therefore, the demand for coatings that can maximize production efficiency by improving mold durability and releasability in high-temperature molding is on the rise.

[Prior art literature]

(Patent Document 0001) Republic of Korea Patent Publication No. 10-2011-0115291: DLC coating device

It is an object of the present invention to provide a mold for molding a glass lens coated with a coating layer including a Si-doped ta-C layer so that it can be used in high-temperature molding when molding a glass lens.

In order to achieve the above object, in one aspect of the present invention

In the mold for forming a glass lens,

The surface in contact with the glass lens being molded is

A mold for forming a glass lens coated with a coating layer including a ta-C layer doped with 3 at% to 20 at% Si is provided.

In addition, in another aspect of the present invention

generating plasma-ized ions by generating a spark in a target body made of graphite;

removing non-ionized particles from the plasmaized ions by magnetic force; and

A ta-C layer doped with 3 at% to 20 at% of Si on the surface in contact with the glass lens of the mold for forming a glass lens with the plasmaized ions while supplying the organic solvent containing Si in gaseous form forming a coating layer to

There is provided a method for manufacturing a mold for forming a glass lens comprising a.

Furthermore, in another aspect of the present invention

forming a coating layer on the surface of the mold for forming a glass lens in contact with the glass lens through the method for manufacturing a mold for forming a glass lens; and

forming a glass lens using a mold for forming a glass lens having the coating layer formed thereon;

There is provided a method of forming a glass lens comprising a.

The mold for forming a glass lens provided in one aspect of the present invention can successfully produce a glass lens without problems such as carbonization even in a high-temperature glass lens forming process. can be maximized. In addition, since it is possible to quickly remove the coating layer through oxygen etching, when a problem occurs in the coating layer, only the coating layer is removed through oxygen etching and re-coating is performed without reprocessing the mold, which takes a long time and high cost. time can be significantly reduced.

1 shows a coating apparatus of a magnetic field filtering arc method used to form a ta-C coating layer in an embodiment of the present invention,

Figure 2 schematically shows a mold coating process for forming a glass lens of an embodiment of the present invention,

Figure 3 schematically shows a coating layer in the form of a multi-layer and a single layer that can be prepared according to an embodiment of the present invention,

4 is a graph showing the doping amount of Si according to the TMS gas flow rate in an embodiment of the present invention,

5 is an image showing the experimental results of the Example 4 sample, according to an experimental example of the present invention;

6 is an image showing the experimental results of the sample of Example 5, according to an experimental example of the present invention;

7 is an image showing an experimental result of a comparative example sample according to an experimental example of the present invention.

Since the present invention can make various changes and thus various embodiments can be made, specific embodiments will be presented below and described in detail.

In addition, all terms in this specification that are not specifically defined may be used in a meaning that is understandable to all those of ordinary skill in the art to which the present invention belongs.

However, it should be understood that the present invention is not intended to be limited only to the specific embodiments to be described below, and includes all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Accordingly, there may be other equivalents and modifications to the embodiments described herein, and the embodiments presented herein are only the most preferred embodiments.

In one aspect of the invention

In the mold for forming a glass lens,

The surface in contact with the glass lens being molded is

A mold for forming a glass lens coated with a coating layer including a ta-C layer doped with 3 at% to 20 at% Si is provided.

Hereinafter, the mold for forming a glass lens provided in one aspect of the present invention will be described in detail for each configuration.

First, the mold for forming a glass lens provided in one aspect of the present invention may include a base material of the mold.

The base material of the mold _{may be at least one selected from the group consisting of SiC, Si 3} N ₄ , WC, TiC, TaC, BN, TiN, ZrO ₂ , cermet, stainless steel, STAVAX, and alloys thereof.

Next, the mold for forming a glass lens provided in one aspect of the present invention may include a coating layer.

In the base material of the mold, the surface in contact with the glass lens to be molded may be coated with the coating layer.

The coating layer may include a ta-C layer doped with 3 at% to 20 at% Si. Preferably, it may be doped with Si of 5 at% to 15 at%, and more preferably, it may be doped with Si of 7 at% to 17 at%.

When Si is doped at less than 3 at%, there is a problem in that it is difficult to sufficiently secure the mold releasability when molding the glass lens, and there is a problem that the film is removed immediately after one-time molding when the mold is used because the releasability is not secured. If Si is doped in excess of 20 at%, the wear resistance of the mold may be reduced, and when a problem occurs in the coating layer, it must be removed and re-coating is performed.

In one embodiment, the coating layer may be formed as a single layer of the ta-C layer doped with 3 at% to 20 at%.

In another embodiment, the coating layer may be formed in the form of a double layer consisting of a ta-C layer and a ta-C layer doped with 3 at% to 20 at% Si.

In the case of a double-layer configuration, sufficient wear resistance is ensured through the ta-C layer with high hardness, and the release property is sufficiently ensured through the ta-C layer doped with Si on the part in contact with the glass lens being molded on the surface of the mold. As such, it is preferable in that it is possible to simultaneously secure release properties and wear resistance.

The thickness of the coating layer may be 30 nm to 300 nm, preferably 50 nm to 250 nm, more preferably 100 nm to 200 nm.

When the thickness of the coating layer is less than 30 nm, there is a problem that it may be difficult to sufficiently secure the durability of the mold, and when the thickness of the coating layer exceeds 300 nm, there is a problem that the removal of the coating layer may be relatively difficult. In addition, the thicker the coating layer, the higher the possibility of peeling due to the stress of the coating layer, which may cause defects in the coating process.

Since the coating layer as described above allows the mold for forming a glass lens to have excellent releasability and durability, it is possible to maximize the service life of the mold and the production efficiency of the glass lens.

In another aspect of the invention

generating plasma-ized ions by generating a spark in a target body made of graphite;

removing non-ionized particles from the plasmaized ions by magnetic force; and

A ta-C layer doped with 3 at% to 20 at% of Si on the surface in contact with the glass lens of the mold for forming a glass lens with the plasmaized ions while supplying the organic solvent containing Si in gaseous form forming a coating layer to

There is provided a method for manufacturing a mold for forming a glass lens comprising a.

Hereinafter, a method for manufacturing a mold for forming a glass lens provided in another aspect of the present invention will be described in detail for each step.

First, in the method for manufacturing a mold for forming a glass lens provided in another aspect of the present invention, a coating layer may be formed on the surface of the mold for forming a glass by using a vacuum arc deposition method of a magnetic field filtration arc method on the surface in contact with the glass lens.

Specifically, the vacuum arc deposition method of the magnetic field filtration arc method comprises the steps of generating a spark in a target body of graphite material to generate plasmaized ions; removing non-ionized particles from the plasmaized ions by magnetic force; and forming a coating layer on the surface of the mold for forming a glass lens in contact with the glass lens.

In the above steps, the vacuum arc deposition method of the magnetic field filtering arc method includes: an arc plasma generating unit generating a plasma ion by generating a spark in a target body of a graphite material; a transport pipe providing a transport path for transporting plasmaized ions to an optical lens to be coated; a magnetic force generating unit for concentrating non-ionized particles of the material transferred through the transfer pipe to the inner wall side by magnetic force; and at least one filter plate formed to block the transfer of the non-ionized particles in the transfer pipe.

The magnetic field filtration arc type coating device may have various forms, for example, may exist in various forms, such as a double bend form, a 90 degree bent form, a 45 degree bent form.

In the case of using the vacuum arc deposition method of the magnetic field filtration arc method, it is preferable in that it can solve the problem that non-ionized micron-sized large particles enter the protective film and deteriorate the film quality.

In addition, when the magnetic field filtration arc method is used, the sp ³ fraction is high and an amorphous carbon protective film without hydrogen can be formed. can be formed

The step of forming a coating layer on the surface of the mold for forming a glass lens in contact with the glass lens is specifically, while supplying an organic solvent containing Si in gaseous form, the glass of the mold for forming a glass lens with the plasmaized ions. The method may include forming a coating layer including a ta-C layer doped with 3 at% to 20 at% Si on a surface in contact with the lens.

The organic solvent containing Si may be at least one selected from the group consisting of tetramethylsilane (TMS), hexamethyldisilazane (HMDS), and hexamethyldisiloxane (HMDSO).

The organic solvent may be supplied in the form of a gas.

In an embodiment, the organic solvent containing Si may be tetramethylsilane (TMS). _{The tetramethylsilane may be doped in the form of -CH X} dangling bond in a state in which the Si-CH ₄ structure is not completely decomposed, thereby lowering the surface energy and reducing the chemical reaction through this to achieve low friction properties of the surface can do.

In addition, in the case of other methods of doping Si such as sputtering, an additional sputtering apparatus is required, and the process is complicated and equipment cost is increased. However, in the case of doping using an organic solvent containing Si, the existing When using the magnetic filtration arc process equipment of

In addition, compared to the method of doping Si through sputtering, in the case of doping using an organic solvent containing Si, the amount of Si doping can be easily controlled by adjusting the flow rate of the organic solvent in the gaseous form containing Si. do.

In addition, in the case of a process such as sputtering, a porous film may be formed due to an increase in the degree of vacuum according to an increase in the amount of Ar gas injected, which may decrease the performance of the coating layer. It is preferable to be able to

In the deposition of ta-C using sputtering, a structure having mainly Si-C bonds may be formed as pure Si deposition is performed. In addition, due to the nature of the sputtering process, Ar gas must be used, which increases the process pressure and reduces ion deposition energy.

On the other hand, in the case of Si-doped ta-C based on arc plasma through the injection of a gaseous organic solvent containing Si, the Si-CH ₃ bond contained in the gaseous organic solvent is partially decomposed to form the surface of the film. Since the degree of slippage of the surface can be improved by including the hydrophobic Si-CH bond, the releasability can be improved.

The coating layer may include a ta-C layer doped with 3 at% to 20 at% Si. Preferably, it may be doped with Si of 5 at% to 15 at%, and more preferably, it may be doped with Si of 7 at% to 17 at%.

When Si is doped at less than 3 at%, there is a problem in that it is difficult to sufficiently secure the mold releasability when molding the glass lens, and there is a problem that the film is removed immediately after one-time molding when the mold is used because the releasability is not secured. If Si is doped in excess of 20 at%, the wear resistance of the mold may be reduced, and when a problem occurs in the coating layer, it must be removed and re-coating is performed.

In one embodiment, the coating layer may be formed as a single layer of the ta-C layer doped with 3 at% to 20 at%.

In another embodiment, the coating layer may be formed in the form of a double layer consisting of a ta-C layer and a ta-C layer doped with 3 at% to 20 at% Si.

In the case of a double-layer configuration as described above, sufficient wear resistance is ensured through the ta-C layer with high hardness, and the release property is sufficiently secured through the ta-C layer doped with Si on the part in contact with the glass lens to be molded on the surface of the mold. As such, it is preferable in that it is possible to simultaneously secure release properties and wear resistance.

When configured in the double-layered form, the forming of the coating layer includes forming a ta-C layer on the surface in contact with the glass lens of the mold for forming a glass lens with the plasmaized ions and an organic solvent containing Si while supplying in gaseous form, forming a ta-C layer doped with 3 at% to 20 at% of Si on the ta-C layer with the plasmaized ions.

The thickness of the coating layer may be 30 nm to 300 nm, preferably 50 nm to 250 nm, more preferably 100 nm to 200 nm.

When the thickness of the coating layer is less than 30 nm, there is a problem that it may be difficult to sufficiently secure the durability of the mold, and when the thickness of the coating layer exceeds 300 nm, there is a problem that the removal of the coating layer may be relatively difficult. In addition, the thicker the coating layer, the higher the possibility of peeling due to the stress of the coating layer, which may cause defects in the coating process.

In addition, the method for manufacturing a mold for molding a glass lens provided in another aspect of the present invention includes the step of etching the mold for molding a glass lens before forming a coating layer on the surface in contact with the glass lens of the mold for molding a glass lens. may include more.

Through the above steps, it is possible to clean the surface of the mold and remove moisture.

In another aspect of the invention

forming a coating layer on the surface of the mold for forming a glass lens in contact with the glass lens through the method for manufacturing a mold for forming a glass lens; and

forming a glass lens using a mold for forming a glass lens having the coating layer formed thereon;

There is provided a method of forming a glass lens comprising a.

The step of forming a coating layer on the surface of the mold for forming a glass lens in contact with the glass lens through the method for manufacturing the mold for forming a glass lens has been described above, and thus will not be repeated.

The step of forming a glass lens using a mold for forming a glass lens having the coating layer formed thereon may be performed at a high temperature of 600° C. or higher. More specifically, it may be 650°C or higher, and more specifically 680°C or higher.

When an abnormality occurs in the coating layer in the step of molding the glass lens, it may include removing the coating layer and re-coating the mold for molding the glass lens.

The step of removing the coating layer may be performed through etching, and in one embodiment, may be performed through oxygen etching.

Since the method for forming a glass lens provided in another aspect of the present invention includes a ta-C layer doped with Si in an appropriate amount, when an abnormality occurs in the coating layer, the coating layer can be easily removed. In the case of the existing mold for forming a glass lens, if there is a problem in the coating layer, there was a problem that the cost occurred and the required time increased as the mold was reprocessed. You can avoid these problems by removing them.

Hereinafter, the present invention will be described in more detail through Examples and Experimental Examples. The scope of the present invention is not limited to specific embodiments, and should be construed by the appended claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

<Example 1>

The base material for forming a glass lens made of WC was etched using argon gas for 150 minutes to clean the surface and remove moisture.

Using the magnetic field filtering arc (filtered cathodic vacuum arc) type coating device of FIG. 1, ta-C coating was first performed on the mold base material for glass lens molding without gas injection for the purpose of securing durability. During ta-C coating, the substrate bias voltage was set to 130 V, and the coating layer was formed with a thickness of about 100 nm.

Then, tetramethylsilane (TMS) gas is supplied at a flow rate of 0, 2, 4, 6, 8, 10, 12 sccm for the purpose of securing releasability on the coated ta-C, and ta-C coating is performed. did. The bias voltage was set to 150 V. It can be understood with reference to FIG. 2 . A coating layer of 50 nm level was formed, and a total coating layer of 150 nm level was formed.

Carbon coating was performed using arc plasma of the graphite target, and the magnetic field filtration arc method was used to make it an anhydrous process.

Specific coating conditions according to each TMS gas supply flow rate are shown in Table 1 below (see FIG. 4 ).

	gas flow (sccm)	Si atomic ratio (at%)	deposition rate (nm/min)	Coating time (min)	working pressure (Torr)
Example 1	0	-	4.23	36	1.1×10 -6
Example 2	2	3.33	5.22	28	5.1×10 -6
Example 3	4	5.68	6.35	24	5.7×10 -6
Example 4	6	8.43	7.66	20	6.2×10 -6
Example 5	8	10.22	8.34	18	6.8×10 -6
Example 6	10	16.55	10.21	15	7.1×10 -6
Example 7	12	21.34	15.64	10	7.5×10 -6

For all TMS gas flow conditions, the formed coating layers were all good.

<Comparative example>

The base material for forming a glass lens made of WC was etched using argon gas for 50 minutes to clean the surface and remove moisture.

A typical anhydrous ta-C coating was applied using the coating device of the filtered cathodic vacuum arc method of FIG. 1 . Unlike the example, a gas was not separately supplied.

Carbon coating was performed using arc plasma of the graphite target, and the magnetic field filtration arc method was used to make it an anhydrous process.

When coating the coating layer, an adhesive layer with a thickness of 20 nm was formed while applying a bias of 300 V, and an abrasion resistance layer of 20 nm level was formed while applying a bias of 150 V on it, and 110 V was applied thereon. A release layer securing layer of nm level was formed.

<Experimental Example 1>

Examples 1, 4, and 7 Samples were evaluated for adhesion and releasability through scratch analysis under a nitrogen environment (actual molding environment).

As shown in the scratch test results of FIG. 5 , in the case of Example 4, it can be seen that the average frictional force was 0.1 level, and the frictional force was reduced by about 50% compared to Example 1 of 0.2 level.

In addition, as can be seen from the scratch track of FIG. 6 , it can be confirmed that the adhesion is improved by about 40% from 15 N in Example 1 to 21 N in Example 4 based on _{L c3 .}

<Experimental Example 2>

For the samples of Examples 1 to 7, it was applied to a molding process at 650° C., and the molding durability, releasability, and the time required to remove the coating layer were measured and shown in Table 2 below.

	Si atomic ratio (at%)	molded durability (shot)	Mold release time (min)	Coating layer removal time (min)
Example 1	-	One	within 30 minutes	within 30 minutes
Example 2	3.33	111	within 15 minutes	within 30 minutes
Example 3	5.68	142	within 10 minutes	within 30 minutes
Example 4	8.43	223	within 10 minutes	within 30 minutes
Example 5	10.22	498	within 10 minutes	within 30 minutes
Example 6	16.55	262	within 10 minutes	within 30 minutes
Example 7	21.34	50 or less	within 10 minutes	within 30 minutes

In the case of Examples 2 to 6, it can be confirmed that there is no problem in durability even when 100 shots or more are performed, the time required for securing releasability is also within 15 minutes, and it can be confirmed that the removal of the coating layer is also possible within 30 minutes. .

In addition, when these optimization conditions are applied, in general, 4 times of oxygen etching process and re-coating process can be performed, and in the case of Example 5, molding durability of up to 2000 shot level can be secured.

In addition, a photograph of the experimental result for Example 4 is shown in FIG. 5 , and a photograph of the experimental result for Example 5 is shown in FIG. 6 .

In particular, in the case of Examples 4 and 5, it can be confirmed that even 1000 shots or more have durability without a problem in molding.

<Experimental Example 3>

Under a nitrogen atmosphere at a temperature of 600°C to 688°C, under a glass lens molding process of molding at a pressure of up to 0.7 MPa, in the sample of Comparative Example, molding durability, releasability, and time required to remove the coating layer according to the bias during the formation of the release layer, etc. evaluated.

The results are shown in Table 3 below.

Bias	molded durability (shot)	Mold release time	Coating layer removal time (min)
0	One	1 hour or more	within 30 minutes
One	One	1 hour or more	within 30 minutes
100	>100	1 hour or more	within 30 minutes
200	>200	1 hour or more	within 30 minutes

When a high bias is applied, initial releasability is secured and release may be possible immediately after molding, but over time, releasability deteriorates and the coating layer at the center of the film may come off.

In addition, when a low bias is applied, the coating layer may immediately come off after 1 shot due to lack of releasability (FIG. 7).

[Explanation of code]

10 Base material

20 coating layer

21 ta-C layer

22 Si-doped ta-C layer

100 Glass lens molding mold

200 magnetic field filtration arc coating device

210 chamber

211 Base plate

212 board

221 Outlet magnet (OM)

222 Extraction magnet (EM)

223 Source magnet (SM)

224 Baffle

231 Substrate bias power supply

232 Duct bias power supply

233 Arc discharge power supply

241 Cathode

242 Anode

243 Arc spot

244 Trigger

Claims (11)

1. In the mold for forming a glass lens,

   The surface in contact with the glass lens being molded is

   A mold for forming a glass lens coated with a coating layer comprising a ta-C layer doped with Si of 3 at% to 20 at%.
2. According to claim 1,

   The coating layer is

   ta-C layer; and

   ta-C layer doped with 3 at% to 20 at% Si;

   A mold for forming a glass lens, characterized in that it comprises a.
3. According to claim 1,

   The base material of the mold for forming the glass lens is at _{least one selected from the group consisting of SiC, Si 3} N ₄ , WC, TiC, TaC, BN, TiN, ZrO ₂ , cermet, stainless steel, STAVAX, and alloys thereof. A mold for forming glass lenses.
4. According to claim 1,

   The Si-doped ta-C layer has a thickness of 30 nm to 300 nm.
5. generating plasma-ized ions by generating a spark in a target body made of graphite;

   removing non-ionized particles from the plasmaized ions by magnetic force; and

   A ta-C layer doped with 3 at% to 20 at% of Si on the surface in contact with the glass lens of the mold for forming a glass lens with the plasmaized ions while supplying the organic solvent containing Si in gaseous form forming a coating layer to

   A method of manufacturing a mold for forming a glass lens comprising a.
6. 6. The method of claim 5,

   The organic solvent containing Si is characterized in that at least one selected from the group consisting of tetramethylsilane (TMS), hexamethyldisilazane (HMDS) and hexamethyldisiloxane (HMDSO). A method for manufacturing a mold for forming a glass lens.
7. 6. The method of claim 5,

   The base material of the mold for forming a glass lens is at _{least one selected from the group consisting of SiC, Si 3} N ₄ , WC, TiC, TaC, BN, TiN, ZrO ₂ , cermet, stainless steel, and alloys thereof. Glass, characterized in that A method for manufacturing a mold for lens molding.
8. 6. The method of claim 5,

   Method for manufacturing a mold for molding a glass lens, characterized in that it further comprises the step of etching the mold for molding the glass lens before the step of forming the coating layer.
9. 6. The method of claim 5,

   The coating layer is

   ta-C layer; and

   ta-C layer doped with 3 at% to 20 at% Si;

   A method for manufacturing a mold for forming a glass lens, comprising:
10. 10. The method of claim 9,

    The step of forming the coating layer is

    forming a ta-C layer on a surface in contact with a glass lens of a mold for forming a glass lens with the plasmaized ions; and

    forming a ta-C layer doped with 3 at% to 20 at% of Si on the ta-C layer with the plasmaized ions while supplying an organic solvent containing Si in gaseous form;

    A method for manufacturing a mold for forming a glass lens, comprising:
11. Forming a coating layer on the surface in contact with the glass lens of the mold for forming a glass lens through the method for manufacturing a mold for forming a glass lens of claim 5; and

    forming a glass lens using a mold for forming a glass lens having the coating layer formed thereon;

    A method of forming a glass lens comprising a.

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