JP2003191248A - Manufacturing method of matrix, matrix, making method of mold for molding optical element and making method of optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a matrix which enables easier manufacture of the matrix of high precision by selecting the optimum material for the matrix and by processing it properly, the matrix manufactured by this method, a making method of a mold for molding an optical element which uses this matrix, and a making method of the optical element molded by this mold. <P>SOLUTION: Resin materials meeting necessary conditions of solvent resistance and hardness are present in large numbers, and as to heat resistance, some thermoplastic plastics have sufficient characteristics thereof. In other words, these resin materials are suitable for the matrix used on the occasion of forming the mold for molding the optical element by making electroforming grow, on condition that they do not soften at a baking temperature being about 180°C generally. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master die manufacturing method for manufacturing an optical element molding die capable of molding an optical element, a mother die, a method for manufacturing an optical element molding die, and an optical element. Regarding the method.

[0002]

2. Description of the Related Art In the field of optical pickup devices, which have been rapidly developing in recent years, extremely high precision optical elements such as objective lenses are used. When a material such as plastic or glass is molded into such an optical element using a mold, a product having a uniform shape can be rapidly manufactured. It can be said that it is suitable for mass production. Here, since the mold is a consumable item, and damage due to an unexpected situation is expected, it is necessary to replace the mold regularly or irregularly in order to mold a highly accurate optical element. Can be said. Therefore,
It can be said that a mold for molding an optical element (also referred to as an optical element molding mold) needs to be prepared in advance to a certain degree with a certain accuracy.

Here, when a die is manufactured by a cutting process using a single crystal diamond tool or the like, it takes time and labor, and it is difficult to cut out a die having the same shape.
Therefore, there is a possibility that the shape of the optical element product may be varied before and after the die replacement, and there is a problem that the cost is high.

In particular, a certain type of optical element used in an optical pickup device is provided with a fine diffraction ring zone having a blazed cross section concentrically with the optical axis of the optical surface in order to improve aberration characteristics. It is being appreciated. When forming a concentric groove corresponding to such a diffractive ring zone on the optical surface transfer surface of the mold, there is a problem that the cutting process takes time and labor. When the optical element molding die is formed of super steel or the like, in order to obtain a desired optical surface transfer surface shape with high precision, cutting with a diamond tool or the like must be performed.

[0005]

To solve the above problems, for example, a mold having a mother optical surface corresponding to the optical surface of the optical element is grown by electroforming through a chemical reaction to form a mold. There is an attempt to make it. When such a die manufacturing method by electroforming is used, it is possible to reduce the dimensional variation only by preparing one master die in which an aspherical surface having an annular zone corresponding to the diffraction annular zone of the optical element is accurately formed. The optical element molding die can be transferred and formed relatively easily.

However, according to such a method, for example, in order to form a ring zone corresponding to the diffraction ring zone, a resist is applied to the surface of the mother die, electronic drawing is performed, development processing is performed, and electroforming processing is performed. Therefore, it is necessary to obtain a mold for molding an optical element. Si or the like is known as a matrix material for this purpose. However, since such a material is poor in workability, when the mother optical surface is cut into an aspherical shape with a diamond tool, it takes 1 day or more until the mirror surface state necessary for obtaining good characteristics as the optical surface of the optical element is obtained. There is a problem that it takes a long processing time. On the other hand, if it is a metal material, the workability is further improved, but it is not suitable for long-term storage due to problems such as surface oxidation, and it can be said that it is unsuitable as a material for a mother die that is stored for a long time and repeatedly used. .

The present invention has been made in view of the problems of the prior art as described above, and by selecting an optimum material for a mother die and performing an appropriate processing, it is possible to more easily realize accuracy. A master mold manufacturing method capable of manufacturing a high master mold, a master mold manufactured by such a manufacturing method, a method of manufacturing an optical element molding mold using the master mold, and a molding method using the optical element molding mold It is an object to provide a method for manufacturing an optical element.

[0008]

According to a first aspect of the present invention, there is provided a mother die manufacturing method in which a resist is coated and baked to manufacture a mother die for molding. The mold base is made of a resin material, and the resin material has a softening point higher than the baking temperature of the resist.

Conventionally, when Si or the like is used as a matrix base material (hereinafter, also referred to as a material) as described above,
Since the workability is poor, it takes time and effort to process.

Therefore, the present inventors have replaced Si with
I wondered if a resin material could be used as the material for the matrix. Many resin materials satisfy the conditions such as hardness suitable for electroforming. However, it has been found that when a resin material is used as the material of the matrix, there arises a problem in the application of the resist for forming a fine pattern such as a diffraction ring zone as described above. Particularly, in the electronic drawing process, a resist baking process is required. When exposed to high temperature during the baking process, the resin material that forms the base of the resist is deformed, making it difficult to reproduce a precise curved surface such as an optical surface.

In view of such circumstances, the present inventors have considered that the resin material used as a material for such a mold is not softened at a baking temperature which is generally around 180 ° C. is there. The softening point means a temperature at which the resin material becomes soft at a temperature higher than the softening point, which represents its physical properties.

That is, in the case of using a method of obtaining an optical element molding die by growing electroforming from a mother die,
As in the present invention, by using a resin material having the above-mentioned characteristics instead of Si or the like as the material of the mother die, it is possible to significantly reduce the labor and time for machining the mother die and improve the machining efficiency. Can be done.

Further, according to the method for producing a mother die of the present invention,
The base material of the mother die has a non-planar portion, and the base material is formed by injection molding the resin material.

When forming a master using a resin material, in the case of forming an aspherical shape of the master optical surface of the master corresponding to the optical surface of the optical element, polishing is performed in order to improve optical characteristics. It is necessary to make the surface mirror-finished by processing or the like, which takes time and labor, and also causes variations among the mother mold individuals. On the other hand, if the non-planar portion (for example, the mother optical surface) is formed by injection molding the resin material, the processing time and labor can be significantly reduced. In other words, if a resin material is used as the material of the master die, the master die can be formed by injection molding, so that the shape of the original die (for example, a complicated curved surface corresponding to the mother optical surface) is accurately transferred and formed at one time. In addition, it is possible to minimize the variation between the mother mold individuals. However,
From the viewpoint of equipment for injection molding, a material having a too high softening point is said to be unsuitable for injection molding. From the above,
The material of the master mold that can be used in the master mold manufacturing method according to the present invention has sufficient solvent resistance to a developing solution and a rinsing solution and hardness at room temperature, while having a softening point higher than the resist baking temperature. It can be said that a resin material having a softening point lower than a general injection molding temperature is suitable.

As such a resin material, a thermoplastic polyimide resin, a polyetherimide resin or the like can be used, but is not limited to these as long as the above-mentioned characteristics are satisfied.

Further, by subjecting the mother die to a surface treatment,
It is preferable to increase the surface hardness of the master mold, for example, because the durability against electroforming treatment can be increased.

The surface treatment is preferably a treatment in which an ultraviolet curable resin is adhered to the surface of the mother die and then an ultraviolet ray is irradiated.

Alternatively, the surface treatment is preferably a treatment for depositing chrome on the surface of the mother die.

A second method of manufacturing a master according to the present invention is a method of manufacturing a master for coating by applying a resist and baking to manufacture a master for molding, wherein the base material of the master to which the resist is applied is a resin. And the baking temperature of the resist is lower than the softening point of the resin material. The above-described first aspect of the present invention is obtained by observing the softening point of the resin material and the resist baking temperature in the opposite positions, and the effects are the same as those described above.

According to such a master block manufacturing method, it becomes possible to mold the master block with high accuracy more easily by using a relatively inexpensive resin material. Therefore, by producing an optical element molding die by using electroforming grown from a range including the non-planar portion (for example, the mother optical surface or a fine ring zone) of the mother die, a highly accurate optical An element molding die can be obtained, and by using the optical element molding die, even an optical element having a diffractive ring zone on the optical surface can be accurately molded.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a flow chart showing steps constituting a master die manufacturing method according to the present embodiment. FIG. 2 is a cross-sectional view showing a material of a mother die (also referred to as a base material) to be processed or an assembly of the electrode member and an electrode member (referred to as a member A) in the main steps shown in FIG. FIG. 3 is a top view of the member A. The master mold manufactured according to the present embodiment has a ring zone corresponding to the diffraction ring zone of the optical element formed on the mother optical surface thereof.

First, in step S101 in FIG. 1, a resin material, which will be described in detail later, is heated and melted at 260 to 400 ° C., and then injected into the spaces in the master molds 1 and 2 to produce the material of the master mold ( This is also referred to as a mother die for convenience) 10 is injection molded.
At this time, no ring zone is formed on the transfer surface 1a of the original die 1, but since it has an aspherical shape corresponding to the optical surface of the optical element, the mother optics of the injection-molded material 10 of the mother die is formed. The aspherical surface is accurately transferred to the surface (that is, the non-planar portion) 10a.

Subsequently, in step S102, the mother material 10 is set on a spin coater (not shown), and the step S is performed.
In 103, press-pinning is performed while the resist L is flown down onto the material 10 of the master mold, and then main spin is performed in step S104 to form the coating of the resist L (FIG. 2).
(See (b)). The reason why the press pin and the main spin are separated is
This is to coat the resist L having a uniform film thickness on the mother optical surface 10a which is a complicated curved surface.

Thereafter, in step S105, the member A is removed from the spin coater, and in step S106, a baking process is performed at an ambient temperature of 180 ° C. for 20 minutes to stabilize the coating film of the resist L. Here, one time resist L
Since a sufficient film thickness cannot be obtained in the film treatment of step S102, steps S102 to S106 are repeated, and when the film of the resist L is laminated to obtain a sufficient film thickness (step S107), in step S108, For details, an electron drawing process is performed on the resist L on the mother optical surface 10a of the mother material 10 using an electron beam drawing device described later (see FIG. 2C).

After the electronic drawing process, in step S109, the mother material 10 is subjected to a developing process and a rinsing process (see FIG. 2 (d)) to remove unnecessary resist, thereby forming a ring shape. The resist L is obtained. Here, if the irradiation time of the electron beam B at the same point is lengthened, the amount of resist removed increases accordingly. Therefore, by adjusting the position and the irradiation time (dose amount), a blazed annular zone can be obtained. The resist L can be left.

Further, in step S110, the surface of the mother optical surface 10a of the mother material 10 is engraved by dry etching using a plasma shower to form a blazed annular zone 1.
0b (exaggerated from the actual drawing) is formed (see FIG. 2E). Further, in step S111, the matrix material 10 is adhered to the electrode member 11 to obtain the member A (see FIG. 2F). The member A obtained through the steps up to here is manufactured as a mother die. After this step, a UV curable resin is applied and adhered on the surface of the mother optical surface 10a of the member A, and UV irradiation or CV is performed.
It is more preferable to increase the hardness of the surface of the chrome by, for example, vapor-depositing chrome by the D treatment, because the durability as a master mold is improved.

Thereafter, in step S112, the mother mold having the surface activated, that is, the member A is immersed in a nickel sulfamate bath, and an electric current is passed between the electrode member 11 and the external electrode 14, whereby electroforming 20 is performed. Grow (Fig. 2 (g))
reference). At this time, by applying the insulating agent to the outer peripheral surface 11f of the electrode member 11, it is possible to suppress the electroformed formation of the portion to which the insulating agent is applied. When the following processing is performed with an allowable tilt angle of 1 minute during injection molding, the axial length of the outer peripheral surface 11f, which is the reference surface on which electroforming is not formed, is 7 mm.
It is desirable to set the above. In the process of growth, the electroformed 20 has an optical surface transfer surface 20a that accurately corresponds to the mother optical surface 10a and an annular surface transfer surface 2 that accurately corresponds to the annular zone 10b.
And 0b.

Then, in step S114, the electrode member 1
With reference to the outer peripheral surface 11 f of No. 1 as a reference, the member A and the electroformed member 20 are integrally formed, and SPDT (Single Point Dia).
The outer surface 20c of the electroformed 20 is cut and processed by attaching it to the chuck so that the rotation axis of the processing machine and the optical axis of the member A coincide with each other. In addition, electroforming 2
0, the pin hole 20d as a positioning portion with the backing member
(Center) and screw hole 20e are machined (FIG. 2 (h)).
reference). After that, the electroforming 20 is released from the member A by cutting at the position indicated by the arrow X in FIG. 2 (h) (step S128). A cylindrical shaft may be formed instead of the pin hole 20d.

In step S115, the optical element molding die thus formed, that is, the electroformed 20 is integrated with a backing member as described below to form the movable core 30.

FIG. 3 is a sectional view of the movable core 30. In FIG. 3, the movable core 30 includes an electroformed member 20 arranged at the tip (right side in the figure) and a pressing portion 3 arranged at the rear end (left side in the figure).
6 and a sliding member 35 arranged between them. The sliding member 35 and the pressing portion 36 serve as a backing member.

The electroformed member 20 is positioned in a predetermined relationship with the sliding member 35 by engaging a pin portion 35a projecting from the center of the end surface of the cylindrical sliding member 35 with the pin hole 20d. , Through the sliding member 35 parallel to the axis 2
Insert the bolts 37 inserted into the two bolt holes 35b into the screw holes 2
The electroformed member 20 is attached to the sliding member 35 by being screwed into 0e.

The sliding member 35 has a screw shaft 35c formed at the center of an end face (left end in the drawing) facing the end face (right end in the drawing) provided with the pin portion 35a, and a substantially cylindrical pressing portion. By being screwed into a screw hole 36 a formed at the end of 36, it is attached to the pressing portion 36 in a predetermined positional relationship. In FIG. 4, the outer peripheral surface 35e of the sliding member 35 is
The diameter is larger than the outer peripheral surface of the portion other than the electroformed 20 and the flange portion 36b of the pressing portion 36.

FIG. 4 is a view showing a state in which an optical element is molded using the movable core 30 thus formed. In FIG. 4, the holding portion 42 that holds the optical element molding die 41 having the optical surface transfer surface 41 a is fixed to the movable side cavity 43. Movable side cavity 43
Has a small opening 43a and a large opening 43b coaxial therewith. When the movable core 30 is inserted into the movable cavity 43, the outer peripheral surface 35e of the sliding member 35 slides on the inner peripheral surface of the small opening 43a, and the flange portion 36 of the pressing portion 36.
The outer peripheral surface 36d of b slides on the inner peripheral surface of the large opening 43b. By being guided by the two sliding portions, the movable core 30 can move in the axial direction without being greatly inclined with respect to the movable cavity 43. The optical element OE is molded by injecting a molten resin between the optical element molding die 31 and the electroforming 20 and pressing the movable core 30 in the direction of the arrow. According to the present embodiment, by using the electroformed 20 as the optical element molding die that is accurately transferred and formed from the matrix material 10, the optical surface of the optical element OE is
The optical surface transfer surface 20a of the electroformed 20 is transferred and formed, and the diffractive ring zone corresponding to the ring zone transfer surface 20b is accurately formed concentrically with the optical axis.

(About Electron Beam Drawing Device) (Description of Configuration) Next, a schematic structure of the entire electron beam drawing device will be described with reference to FIG. FIG. 5 is an explanatory diagram showing the overall configuration of the electron beam writing apparatus of this example.

As shown in FIG. 5, the electron beam drawing apparatus 401 forms a high-resolution electron beam probe with a large current and scans the mother material 10 to be drawn at a high speed. Electron beam generating means for forming an electron beam probe to generate an electron beam and irradiate the target with a beam, an electron gun 412, a slit 414 for passing the electron beam from the electron gun 412, and a slit 414. An electron lens 416 for controlling the focus position of the electron beam passing through the substrate 10 with respect to the material 10 of the master mold,
The aperture 418 arranged on the path through which the electron beam is emitted to form a desired electron beam shape by the opening, and the scanning position on the material 10 of the master mold, which is the target by deflecting the electron beam, are displayed. Deflector 4 to control
20 and a correction coil 422 that corrects the deflection. It should be noted that each of these parts is equivalent to the lens barrel 410.
It is arranged inside and is maintained in a vacuum state when the electron beam is emitted.

Further, the electron beam drawing apparatus 411 includes an XYZ stage 430, which is a mounting table on which the matrix material 10 to be drawn is mounted, and the XYZ stage 43.
0, a loader 440, which is a transporting means for transporting the master die material 10 to a mounting position, and a measuring means, which is a measuring means for measuring a reference point on the surface of the master die material 10 on the XYZ stage 430. The device 480 and a stage driving unit 450 which is a driving unit for driving the XYZ stage 430.
And a loader drive device 460 for driving the loader,
A housing 41 including the inside of the lens barrel 410 and the XYZ stage 430
Evacuation device 470 for evacuating 1
And an observation system 491 for observing the material 10 of the master mold, and a control circuit 492 which is a control means for controlling these.

The electron lens 416 includes coils 417a, which are installed at a plurality of locations along the height direction at a distance from each other.
A plurality of electronic lenses are generated by the respective current values of 417b and 417c, so that the electronic lenses are respectively controlled and the focal position of the electron beam is controlled.

The measuring device 480 includes a first laser length measuring device 482 for measuring the mother material 10 by irradiating the mother material 10 with a laser, and a first laser measuring device 482. The emitted laser light (first irradiation light) reflects the matrix material 10 and receives the reflected light from the first light receiving portion 484 and the first laser length measuring device 482 from different irradiation angles. Second laser length measuring device 486 for irradiation
And a second light receiving portion 488 that receives the reflected light by the laser light (second irradiation light) emitted from the second laser length measuring device 486 and reflects the material 10 of the mother die. It is composed of.

The stage drive means 450 includes an X-direction drive mechanism 452 for driving the XYZ stage 430 in the X-direction,
It includes a Y-direction drive mechanism 454 that drives the XYZ stage 430 in the Y-direction, a Z-direction drive mechanism 456 that drives the XYZ stage 430 in the Z-direction, and a θ-direction drive mechanism 458 that drives the XYZ stage 430 in the θ-direction. It is composed of. As a result, the XYZ stage 430 can be operated three-dimensionally and alignment can be performed.

The control circuit 492 is not shown,
An electron gun power supply unit for supplying power to the electron gun 412, an electron gun control unit for adjusting and controlling current, voltage and the like in the electron gun power supply unit, and an electronic lens 416 (each of a plurality of electronic lenses) are provided. A lens power source for operating the lens power source and a lens controller for adjusting and controlling each current corresponding to each electron lens in the lens power source are included.

The control circuit 492 further includes a coil control unit for controlling the correction coil 422, a shaping deflecting unit for deflecting the forming direction by the deflector 420, and a deflecting unit for deflecting in the sub-scanning direction by the deflector 420. Sub-deflection unit for deflector 420
, A main deflection unit for performing deflection in the main scanning direction, an electric field control circuit that is electric field control means for controlling the electric field of the electron beam,
A pattern generation circuit for generating a drawing pattern or the like on the master material 10, various laser control systems, a stage control circuit for controlling the stage driving means 450, a loader control circuit for controlling the loader driving device 460,
A measurement information input unit for inputting measurement information, a memory that is a storage unit for storing the input information and other plurality of information, a program memory storing a control program for performing various controls, and each unit And a control unit that controls each of these units, for example, a control unit formed of a CPU or the like.

(Explanation of Operation) In the electron beam drawing apparatus 401 having the above-described structure, when the mother material 10 conveyed by the loader 440 is placed on the XYZ stage 430, the vacuum evacuation device 470 mirrors it. Cylinder 41
0 and the air and dust in the housing 411 are exhausted, and then an electron beam is emitted from the electron gun 412.

The electron beam emitted from the electron gun 412 is deflected by the deflector 420 via the electron lens 416, and the deflected electron beam B (hereinafter, the deflection-controlled electron beam after passing through the electron lens 416) is deflected. May be referred to as "electron beam B" only)
Drawing is performed by irradiating the drawing position on the surface of the mother die material 10 on the XYZ stage 430, for example, the curved surface portion (curved surface) 12.

At this time, the measuring device 480 measures the drawing position (at least the height position of the drawing position) on the mother die material 10 or the position of a reference point as described later, and the control circuit 492 Based on the measurement result, the current values flowing through the coils 417a, 417b, 417c of the electron lens 416 are adjusted and controlled, and the electron beam B
The position of the depth of focus, that is, the focus position is controlled, and movement is controlled so that the focus position becomes the drawing position.

Alternatively, based on the measurement result, the control circuit 4
92 controls the stage driving means 450 to move the XYZ stage 430 so that the focal position of the electron beam B becomes the drawing position.

In this example, either one of the electron beam control and the XYZ stage 430 control may be performed, or both may be used.

Next, the first laser beam length measuring device 482 of the measuring apparatus 480 irradiates the material 10 of the master mold with the first light beam S1 from the direction intersecting the electron beam, and the material 10 of the master mold is irradiated. The first light intensity distribution is detected by receiving the transmitted first light beam S1.

At this time, since the first light beam S1 is reflected by the bottom of the material 10 of the master mold, based on the first intensity distribution, the height (height) on the flat portion of the material 10 of the master mold is increased. ) The position will be measured and calculated. However, in this case, the (height) position of the mother material 10 on the mother optical surface 10 cannot be measured.

Therefore, in this example, a second laser length measuring device 486 is further provided. That is, by the second laser length measuring device 486, the material 10 of the master mold is moved from a direction substantially orthogonal to the electron beam different from the first light beam S1.
The second light beam S2 is applied to
When the second light beam S2 that passes through is received by the second light receiving unit 488, the second light intensity distribution is detected, and the position is measured and calculated based on this.

Then, with the height position of the matrix material 10 as a drawing position, for example, the focus position of the electron beam is adjusted and drawing is performed.

(Example) One resin material suitable for use as the material of the matrix according to this embodiment is a thermoplastic polyimide resin (the glass transition point which is a measure of the softening point is 260).
℃), for example, product name Bestel T from DuPont
The products marketed as P and those marketed under the trade name Aurum by Mitsui Chemicals, Inc. can be used. Further, another resin material suitable for use as the material of the matrix is a polyetherimide resin (the glass transition point which is a standard of the softening point is 220 ° C.), for example, from Japan GE Plastics under the trade name Ultem. The one on the market can be used.

Table 1 shows the results of the solvent resistance test conducted by the present inventors. Specifically, the dimensional change in one side direction (A), the dimensional change in the other side direction (B), the weight change, and the surface roughness before and after the rectangular sample was immersed in the solution for a predetermined time were measured. It is a thing.

[Table 1]

Sample: Vestel TP marketed by DuPont Co., Ltd. (1) Resist solution immersion test sample was used as a thinning solution (ethyl cellosolve acetate) for positive resist material trade name "OEBR-1000" manufactured by Tokyo Ohka Kogyo Co., Ltd. : ECA) for 2 hours and allowed to air dry. (2) OEB in which the developer immersion test sample was maintained in the range of 25.0 to 25.1 ° C
It was dipped in a developing solution for R-1000 (isoamyl acetate 90%, ethyl acetate 10%) for 3 hours and dried in a nitrogen gas atmosphere. (3) Rinse liquid immersion test The sample was immersed in isopropyl alcohol maintained in the range of 23.2 to 23.6 ° C for 3 hours and dried in a nitrogen gas atmosphere. The evaluation method is as described in the table.

According to the test results of the present inventors, the dimensional change is 0.04% at maximum in the rinse liquid immersion, and the weight change is 0.2% at the maximum in the developer immersion liquid. Was the same before and after the test, and it was confirmed that the solvent had sufficient solvent resistance.

Table 2 shows the results of the heat resistance test conducted by the present inventors. Similar to the solvent resistance test described above, a dimensional change in one side direction (A), a dimensional change in the other side direction (B), a weight change, and a surface roughness were measured before and after processing a rectangular sample. Is.

[Table 2]

Sample: Vestel TP, trade name marketed by DuPont (1) Single baking treatment The sample was subjected to a baking treatment at 180 ° C. for 20 minutes once. (2) Two-time baking treatment The sample was subjected to two baking treatments at 180 ° C for 20 minutes. From the previous baking treatment to the next baking treatment, heat was naturally radiated in the clean room until the sample temperature returned to 23 ° C. (3) Baking treatment three times The sample was baked three times at 180 ° C. for 20 minutes. From the previous baking treatment to the next baking treatment, heat was naturally radiated in the clean room until the sample temperature returned to 23 ° C. The evaluation method is as described in the table.

According to the test results of the present inventors, the change in dimension is 0.05% at maximum in the three-time baking treatment, and the weight change is −0.5% in the maximum at three-time baking treatment. It was confirmed that all were within the allowable range and had sufficient heat resistance. The surface roughness was the same before and after the test.

Although the present invention has been described with reference to the exemplary embodiments and examples, the present invention should not be construed as being limited to the above-described exemplary embodiments, but may be appropriately changed or improved (embodiments). Of course is also possible).

[0059]

EFFECTS OF THE INVENTION According to the present invention, by selecting the most suitable resin material as the material of the mother die and performing the appropriate processing,
A master mold manufacturing method capable of manufacturing a master mold more easily and at low cost with high accuracy, a master mold manufactured by such a manufacturing method,
Further, it is possible to provide a method for manufacturing an optical element molding die using such a mother die, and a method for manufacturing an optical element molded by the optical element molding die.

[Brief description of drawings]

FIG. 1 is a flowchart showing steps constituting a master die manufacturing method according to the present embodiment.

FIG. 2 is a cross-sectional view of a member including a material of a mother die to be processed in the main steps shown in FIG.

FIG. 3 is a sectional view of a movable core 30.

FIG. 4 is a diagram showing a state in which an optical element is molded using the movable core 30.

FIG. 5 is an explanatory diagram showing an example of the configuration of an electron beam drawing apparatus.

[Explanation of symbols]

A member 10 Mother material 11 Electrode member 401 Electron beam drawing device

Claims (15)

[Claims] 1. A method of manufacturing a master mold for applying a resist and baking to manufacture a master mold for molding, wherein a base material of the master mold to which the resist is applied is made of a resin material, and the resin material is A method for producing a master mold, which has a softening point higher than a baking temperature of a resist. 2. The method of manufacturing a master mold according to claim 1, wherein the base material of the master mold has a non-planar portion, and the base material is formed by injection molding the resin material. . 3. The mother die manufacturing method according to claim 1, wherein the resin material is a thermoplastic polyimide resin or a polyetherimide resin. 4. The surface hardness of the mother die is increased by subjecting the mother die to a surface treatment.
The method for producing a mother die according to any one of 1. 5. The method for producing a mother die according to claim 4, wherein the surface treatment is a treatment in which an ultraviolet curable resin is attached to the surface of the mother die and then ultraviolet rays are irradiated. 6. The surface treatment is a treatment for depositing chrome on the surface of the mother die.
The method for producing a mother die as described in. 7. A mother die manufacturing method for producing a mother die for molding by applying and baking a resist, wherein a base material of the mother die to which the resist is applied is made of a resin material, and A method for producing a mother die, characterized in that the temperature is made lower than the softening point of the resin material. 8. The method of manufacturing a master mold according to claim 7, wherein the base material of the master mold has a non-planar portion, and the base material is formed by injection molding the resin material. . 9. The method according to claim 7, wherein the resin material is a thermoplastic polyimide resin or a polyetherimide resin. 10. The surface hardness of the mother die is increased by subjecting the mother die to a surface treatment.
9. The method for producing a mother die according to any one of 9. 11. The method of manufacturing a master mold according to claim 10, wherein the surface treatment is a treatment in which an ultraviolet curable resin is adhered to the surface of the master mold and then ultraviolet rays are irradiated. 12. The mother die manufacturing method according to claim 10, wherein the surface treatment is a treatment of depositing chrome on the surface of the mother die. 13. A mother die manufactured by the mother die manufacturing method according to any one of claims 1 to 12. 14. An optical element molding die is produced by using electrocasting grown from a range including the non-planar portion of the mother die according to claim 13. How to make a mold. 15. A method for manufacturing an optical element, which comprises molding an optical element using the optical element molding die manufactured by the method for manufacturing an optical element molding die according to claim 9. Description: