JP5857960B2 - Optical element manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing an optical element having a minute optical surface and an optical element, and more particularly to an optical element suitable for a recording head of an optically assisted magnetic recording apparatus and a method for manufacturing the optical element.

  Conventionally, as a method for manufacturing an optical element, a method using molding or polishing using a mold is known.

  On the other hand, the following is known as a manufacturing method of a minute optical element used in the fields of optical communication and optical information processing. For example, as a method of manufacturing an optical path conversion mirror having a minute reflecting surface, a mirror groove is dug by dry etching, a surface treatment agent is applied to the wall surface and bottom surface of the mirror groove, and then a liquid curable resin is applied to the mirror groove from an inkjet nozzle. It is known to supply a mirror support slope to form a reflective film on the slope after curing (see, for example, Patent Document 1).

JP 2009-265275 A

  However, the manufacturing method of the optical path conversion mirror described in the above-mentioned Patent Document 1 has a problem that the machining is complicated, the mass productivity is poor, and the cost is high.

  In view of the above problems, the present invention is a method for manufacturing a micro optical element that is easy to manufacture and rich in mass productivity by a simple process, a low cost micro optical element, and an optically assisted magnetic recording head having the optical element, It is another object of the present invention to provide a magnetic recording apparatus having the magneto-optical recording head.

The above object is achieved by the following configurations (1) to (9).
Specifically, according to the present invention, there is provided an optical element manufacturing method characterized in that, in the configuration (1), the method includes a step of forming a reflective film on a fillet-shaped concave surface portion after the step of curing the resin. The

  (1) A step of extending a liquid resin on a flat surface, a plate-like or film-like substrate is placed on the flat surface on which the resin is extended, and the wall surface of the substrate and the flat surface A method of forming a fillet shape of the resin and a step of curing the resin.

  (2) The method for manufacturing an optical element according to (1), further comprising a step of forming a reflective film on the concave surface portion of the fillet shape after the step of curing the resin.

  (3) The method of manufacturing an optical element according to (2), further including a step of cutting the base material into a strip shape after the step of forming a reflective film on the concave surface portion of the fillet shape.

  (4) A surface made of a resin different from the base material is formed on one plane side of the plate-like or film-like base material, connected to the surface made of the resin, and made of the resin on at least one wall surface portion of the base material An optical element having a fillet shape.

  (5) The optical element according to (4), wherein a reflective film is formed on the fillet-shaped concave surface portion, and the concave surface portion is used as a reflective surface.

  (6) The optical element according to (4) or (5), wherein the concave surface portion has a cylindrical shape.

  (7) The optical element according to any one of (4) to (6), wherein the resin is any one of an ultraviolet curable resin, a thermosetting resin, and an electron beam curable resin.

  (8) A light source, an optical element according to any one of (5) to (7) that reflects a light beam from the light source, a waveguide that guides the light beam reflected by the optical element to a disk, and magnetic recording And an optically assisted magnetic recording head.

  (9) A magnetic recording apparatus comprising: the optically assisted magnetic recording head according to (8); a support member that supports the optically assisted magnetic recording head; and a magnetic recording medium.

  That is, the inventor of the present application places the base material on a flat surface in which the liquid resin is extended, so that the fillet shape of the liquid resin formed between the wall surface and the flat surface of the base material is an optical surface. It is an invention that was found to be usable as

  According to the present invention, it is possible to provide a manufacturing method of a micro optical element that is easy to manufacture and rich in mass productivity by a simple process, and is a low cost micro optical element, and an optically assisted magnetic recording head having the optical element It is possible to provide a magnetic recording apparatus having the magneto-optical recording head.

It is a flowchart which shows the schematic process of the manufacturing method of the optical element which concerns on this Embodiment. It is a schematic diagram which shows the schematic process of the manufacturing method of the optical element which concerns on this Embodiment. It is a schematic diagram which shows the schematic process of the manufacturing method of the optical element which concerns on this Embodiment. It is a schematic diagram which shows the schematic process of the manufacturing method of the optical element which concerns on this Embodiment. It is a schematic diagram which shows the schematic process of the manufacturing method of the optical element which concerns on this Embodiment. It is a schematic diagram which shows the schematic process of the manufacturing method of the optical element which concerns on this Embodiment. It is a schematic diagram which shows the schematic process of the manufacturing method of the optical element which concerns on this Embodiment. It is a schematic diagram which shows the schematic process of the manufacturing method of the optical element which concerns on this Embodiment. It is a perspective view which shows the optical element which concerns on this Embodiment. 1 is a schematic cross-sectional view in which an optical element according to an embodiment is applied to an optically assisted magnetic recording head. FIG. 6 is a perspective view illustrating a schematic configuration example of a magnetic recording apparatus including the optically assisted magnetic recording head illustrated in FIG. 5.

  Hereinafter, the present invention will be described with reference to embodiments, but the present invention is not limited thereto.

  FIG. 1 is a flowchart showing schematic steps of a method for manufacturing an optical element according to the present embodiment. 2 and 3 are schematic views showing schematic steps of the method of manufacturing an optical element according to the present embodiment. Hereafter, it demonstrates using the flow of the manufacturing method of the optical element of FIG. 1 using FIG. 2, FIG.

  In the method of manufacturing an optical element according to the present embodiment, first, a liquid curable resin is extended on a flat surface (step S101). In this step, as shown in FIG. 2A, a liquid resin 20 is dropped on a pedestal 15 having a flat surface such as a glass plate or a metal plate, and extended to a substantially uniform thickness. A substantially uniform thickness can be obtained by spin coating, coating, or the like.

  The curable resin includes a thermosetting type and an active energy ray curable type. Examples of the translucent resin include a thermosetting silicone resin, an epoxy resin, and an acrylic resin, and an active energy ray curable resin. As the active energy ray curable resin, an ultraviolet curable type is preferable from the viewpoints of handleability, irradiation device cost, and safety. Examples of the ultraviolet ray curable resin composition include an epoxy system by cationic polymerization, an acrylic system by radical polymerization, a polythiol / polyallyl system, and the like, preferably an epoxy system. As the epoxy system, a composition comprising a prepolymer containing two or more epoxy groups in one molecule and a cationic polymerization initiator is preferable. Examples of such a prepolymer include alicyclic polyepoxides and polybasic acids. Polyglycidyl esters, polyglycidyl ethers of polyhydric alcohols, polyglycidyl ethers of aromatic polyols, hydrogenated compounds of polyglycidyl ethers of aromatic polyols, polyglycidyl ethers of polyoxyalkylene glycols, urethane polyepoxy compounds And epoxidized polybutadienes. Examples of the cationic polymerization initiator include aromatic onium salts.

  The surface of the flat surface on which the resin of the pedestal 15 extends is formed so that it can be easily peeled off when the curable resin is cured. For example, a releasable coating layer may be provided on the flat surface.

  Next, as shown in FIG. 2B, the plate-like or film-like substrate 30 is placed in the region of the liquid resin 20 (step S102). Although not shown, the base material 30 is preferably lifted by suction or the like and is gently placed in the region of the liquid resin 20 from above.

  The material of the substrate 30 is glass or resin, and a plate or film is preferably used, but is not limited thereto. Moreover, although the thickness of the base material 30 is arbitrary, about 1/50 (mm)-1/2 (mm) are preferable.

  When the base material 30 is placed in the region of the liquid curable resin 20 in step S102, the cross section AA shown in FIG. 2C is provided between the wall surface of the base material 30 and the flat surface of the pedestal 15. Thus, the fillet shape F is formed by the liquid curable resin 20.

  The fillet shape F differs depending on the material characteristics such as the material of the base material 30, the angle of the wall surface with respect to the flat surface, the surface roughness of the wall surface, the amount of the resin 20, viscosity, and surface tension. That is, the desired fillet shape F can be stably obtained by selecting the resin 20 and changing the material of the base material 30, the angle of the wall surface, the surface roughness, etc., and determining these conditions in advance through experiments. it can.

  In this step, the substrate 30 may be pressed after the substrate 30 is placed.

  Next, in the state shown in FIG. 2B, the liquid curable resin is cured (step S103). When the resin is an ultraviolet curable resin, it is irradiated with ultraviolet light, when it is a thermosetting resin, it is left in a high temperature environment for a predetermined time, and when it is an electron beam curable resin, it is cured by irradiation with a predetermined electron beam. Can be made.

  When the curing of the resin is completed, the cured resin 25 and the base material 30 are integrally peeled off from the flat surface of the base 15 as shown in FIG. 3A (step S104).

  Next, as shown in FIG. 3B, the excess resin portion is deleted (step S105), and a reflective film is formed on the concave surface portion on the fillet shape F as shown in the cross-sectional view along the line BB in FIG. Is formed (step S106). The reflective film can be formed by vapor deposition of gold, silver, aluminum, or the like, or plating after forming a predetermined underlayer, but is not limited thereto.

  Next, the optical element 40 in which the reflecting surface R is formed on the fillet shape F is completed by cutting into strips along the broken line shown in FIG. 3D (step S107). In other words, a large number of minute optical elements having the same shape can be manufactured at a time by the series of steps described above.

  As described above, in the method of manufacturing an optical element according to the present embodiment, a base material is placed on a flat surface in which a resin is extended, and a fillet shape is formed between the wall surface of the base material and the flat surface. Is formed and cured, and the fillet shape is used as an optical element, which does not require complicated processing, can be easily manufactured by a simple process, and can be a low-cost mass-productive manufacturing method. . Further, by cutting into strips, it becomes possible to obtain a minute optical element with reduced cost per one.

  Furthermore, as described above, the fillet shape formed by this manufacturing method varies depending on the material characteristics such as the material of the base material, the angle of the wall surface with respect to the flat surface, the surface roughness of the wall surface, the amount of resin, the viscosity, and the surface tension. Therefore, the degree of freedom of selection of these conditions is large, and there is an effect that an arbitrary desired shape can be easily obtained by selecting as appropriate.

  In addition, among the above-mentioned flows, step S104 to step S106 are not limited to this order, and may be interchanged. Further, in the above-described flow, the example in which the cured resin 25 and the base material 30 are separated from the pedestal 15 has been described. However, the present invention is not limited to this, and the step S104 is omitted, and the pedestal 15, the cured resin 25, and The structure which manufactures the base material 30 integrally as an optical element may be sufficient.

  FIG. 4 is a perspective view showing the optical element 40 according to the present embodiment.

  In the optical element 40 manufactured by the manufacturing method as described above, a layered surface 25p of the cured resin 25 is formed on one plane side of the strip-shaped substrate 30, and the substrate 30 is connected to this surface. A fillet shape F made of the cured resin 25 is formed on the wall surface portion 30h. A reflective surface R is formed on the concave surface portion of the fillet shape F. Further, the concave surface portion on which the reflection surface R is formed has a cylindrical shape having no curvature in the X direction in the drawing and having a curvature in the Z direction in the drawing. For this reason, it functions as a one-dimensional condensing element having power for converging the light beam in the YZ plane shown in the figure.

  FIG. 5 is a schematic sectional view in which the optical element according to the present embodiment is applied to an optically assisted magnetic recording head.

  An optically assisted magnetic recording head 3 shown in FIG. 5 is a minute optical recording head that uses light for information recording on the disk 2 and has a light source unit 9A, a slider 10, and a function as a one-dimensional condensing element. The optical element 40 etc. which concern on embodiment are provided.

  The light source unit 9A has a semiconductor laser. The light source unit 9A may be a combination of a semiconductor laser and an optical element such as an optical fiber, an optical waveguide, or a collimating lens.

  The slider 10 is formed of a substrate, and a magnetic reproducing unit 8C, an optical assist unit 8A, and a magnetic recording unit 8B are stacked inside the substrate in order from the inflow side to the outflow side of the recording portion of the disk 2 (in the direction of arrow mC). It is formed in a state.

  The optical assist unit 8A has a planar waveguide, and the planar waveguide has a condensing function for spot heating the recording portion of the disk 2 with near-infrared laser light.

  The optical element 40 is arranged such that the reflection surface R bends the laser light emitted from the light source unit 9A and guides it to the light assist unit 8A. At this time, the laser beam is guided to the light assist unit 8A by the reflecting surface R while converging the light beam in the YZ plane shown in the drawing.

  5 shows the optical element 40 shown in FIG. 4 bonded and fixed to the light source unit 9A, but the present invention is not limited to this. For example, when the pedestal 15, the cured resin 25, and the base material 30 are integrally formed as the optical element 40, the pedestal 15 and the slider 10 may be bonded and fixed.

  By using the low-cost micro optical element 40 according to the present embodiment, the optically assisted magnetic recording head can be formed at low cost.

  FIG. 6 is a perspective view showing a schematic configuration example of the magnetic recording apparatus 1 including the optically assisted magnetic recording head 3 shown in FIG.

  A magnetic recording apparatus 1 shown in FIG. 6 includes a recording disk (magnetic recording medium) 2, a suspension 4 that is rotatable about a support shaft 5 in an arrow mA direction (tracking direction), and is attached to the suspension 4. A housing 7 is provided with the tracking actuator 6, the optically assisted magnetic recording head 3 attached to the tip of the suspension 4, and a motor (not shown) that rotates the disk 2 in the arrow mB direction. Thus, the optically assisted magnetic recording head 3 is configured to be relatively movable while flying over the disk 2 (the disk 2 moves in the direction of arrow mC in FIG. 5).

  By using the optically assisted magnetic recording head according to the present embodiment, an optically assisted magnetic recording apparatus can be formed at low cost.

  It should be noted that the Japanese Patent Application No. 1993 filed on July 26, 2010, including the specification, claims, drawings and abstract. The entire disclosure of 2010-166880 is incorporated in its entirety into this application.

  As described above, the present invention is suitable for a method of manufacturing an optical element having a minute optical surface, an optical element, an optically assisted magnetic recording head, and a magnetic recording apparatus.

1 Magnetic recording device 2 Disk (magnetic recording medium)
DESCRIPTION OF SYMBOLS 3 Optical assist magnetic recording head 4 Suspension 5 Support shaft 6 Actuator 7 Case 8A Optical assist part 8B Magnetic recording part 8C Magnetic reproduction part 9A Light source part 10 Slider 15 Base 20 Resin (liquid)
25 Resin (after curing)
30 base material 30h wall surface part (base material)
40 Optical element F Fillet shape R Reflective surface

Claims (2)

Extending a liquid resin on a flat surface;
Placing a plate-like or film-like substrate on the flat surface from which the resin extends, and forming a fillet shape by the resin between the wall surface of the substrate and the flat surface;
Curing the resin;
After the step of curing the resin, forming a reflective film on the fillet-shaped concave surface portion;
A method for producing an optical element, comprising: After the step of forming a reflective film on the concave portion of the fillet shape,
The method for producing an optical element according to claim 1 , further comprising a step of cutting the substrate into a strip shape.

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