JP2011191396A - Optical element and method for manufacturing optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element and a method for manufacturing the optical element in which peeling can be prevented by enhancing adhesion of a thin film formed on a substrate. <P>SOLUTION: An optical function film 13 and an optical face 11 are formed on the substrate 10 for transmitting light. A region through which light transmitted by the optical face 11 passes out of the surface of the substrate 10 is covered with a mask formed by photolithography or potting, or a previously formed mask member. A region other than the masked region is surface-roughened, and the optical function film 13 and the optical face 11 are formed on the surface of the substrate 10 including a surface roughened region. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical element in which an optical surface and an optical functional film are formed on a substrate that transmits light, and a method for manufacturing the optical element, and in particular, an optical element having high adhesion to a resin substrate on which the optical functional film and the optical surface are formed. And an optical element manufacturing method.

  Conventionally, an optical element in which an optical surface such as a lens is formed on a substrate made of glass or resin that transmits light is known. An optical element can be efficiently formed by arranging and forming optical surfaces in an array on a substrate and cutting the substrate by dicing.

  In addition, a thin film may be formed on the substrate together with the optical surface. The thin film is made of a material that does not transmit light, for example, an aperture that functions as a diaphragm formed over a region other than a region through which light transmitted through the optical surface passes, and a material that does not transmit a predetermined wavelength band such as infrared light And an IR cut filter formed over the entire surface of the substrate. Patent Document 1 discloses an example in which a light-shielding film is formed on a transparent substrate and used as a lens diaphragm.

JP 2009-28952 A

  When a thin film is formed on the surface of the substrate, the thin film may be peeled off by dicing thereafter. In addition, when an optical surface is formed on the surface of the substrate using a mold, the resin adheres to the mold, and an optical surface having a predetermined shape may not be formed. This is due to the low adhesion between the thin film and the substrate or between the resin and the substrate.

  The present invention has been made in view of the above problems, and provides an optical element and a method for manufacturing the optical element that can increase the adhesion of a thin film or an optical surface formed on a substrate and prevent peeling. With the goal.

In order to solve the above problems, an optical element according to the present invention is an optical element in which an optical functional film and an optical surface are formed on a substrate that transmits light.
Of the surface of the substrate, a region other than a region through which light passing through the optical surface passes is roughened, and the optical functional film and the optical surface are formed on the surface of the substrate including the roughened region. Is formed as a film.

The optical element manufacturing method according to the present invention is an optical element manufacturing method in which an optical functional film and an optical surface are formed on a substrate that transmits light.
A region of the surface of the substrate through which the light transmitted through the optical surface passes is covered with a mask, a region other than the region covered with the mask is roughened, and the mask is removed to roughen the surface. The optical functional film is formed on the surface of the substrate including the region, and an optical surface is formed.

Furthermore, an optical element manufacturing method according to the present invention is an optical element manufacturing method in which an optical functional film and an optical surface are formed on a substrate that transmits light.
A region of the surface of the substrate through which the light transmitted through the optical surface passes is covered with a mask, a region other than the region covered with the mask is roughened, and the surface of the substrate including the roughened region is included. The optical functional film is formed on the surface, the mask is removed, and an optical surface is formed on the surface of the substrate.

  Furthermore, the method for manufacturing an optical element according to the present invention is characterized in that the mask is formed by photolithography or potting.

  In the method of manufacturing an optical element according to the present invention, the mask includes a mask member that contacts a predetermined area of the substrate, the mask member is attached to the substrate to cover the predetermined area, and the mask is formed after the rough surface processing. The mask is removed by removing the member from the substrate.

  According to the optical element of the present invention, the region other than the region through which the light transmitted through the optical surface passes out of the surface of the substrate is roughened and optically applied to the surface of the substrate including the roughened region. By forming the functional film or optical surface, it is possible to improve the adhesion of the optical functional film or optical surface to the substrate, so that peeling can be prevented, while optical properties can be affected. Can not be.

  Further, according to the method of manufacturing an optical element according to the present invention, a region of the surface of the substrate through which light transmitted through the optical surface passes is covered with a mask, and regions other than the masked region are roughened to remove the mask. Then, an optical functional film is formed on the surface of the substrate including the roughened region and an optical surface is formed, or a region of the substrate surface through which light passing through the optical surface passes is masked and masked. By roughing the region other than the region, forming an optical functional film on the surface of the substrate including the roughened region, removing the mask and forming the optical surface on the surface of the substrate, thereby improving the optical characteristics. It is possible to improve the adhesion of the optical functional film to the substrate while preventing the influence.

  Furthermore, according to the method for manufacturing an optical element according to the present invention, the mask can be manufactured at low cost by being formed by potting.

  Furthermore, according to the method of manufacturing an optical element according to the present invention, the mask is formed of a mask member that comes into contact with a predetermined area of the substrate, and the mask member is attached to the substrate to cover the predetermined area. By removing the mask by removing it from the substrate, the process of forming and removing the mask on the surface of the substrate can be simplified.

It is sectional drawing of the lens unit in this embodiment. It is sectional drawing showing the manufacturing process of the 1st optical element. It is a schematic diagram showing the process of roughening. It is sectional drawing showing the manufacturing process of the 2nd optical element. It is a conceptual sectional view in the case of masking using a mask member. It is a perspective view of the state which masked the large board | substrate with the mask member of the 2nd form. It is a perspective view of the state which masked the large board | substrate with the mask member of the 3rd form.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a lens unit including an optical element to which the present invention is applied. As shown in this figure, the lens unit includes a first optical element 1, a second optical element 2, and a sensor 3 that are spaced apart from each other.

  In the first optical element 1, a first optical surface 11 and a second optical surface 12 are formed on each surface of the first substrate 10 that transmits light. The first optical surface 11 is formed on a surface facing the outside of the first substrate 10, and the second optical surface 12 is formed on a surface facing the sensor 3 side of the first substrate 10.

  In the first optical element 1, a light shielding film 13 is formed on the surface on which the first optical surface 11 of the first substrate 10 is formed. The light shielding film 13 is formed by forming a layer having a property of not transmitting visible light in a thin film shape, and a circular opening 13a having a predetermined diameter is formed. Examples of the material having necessary characteristics for the light shielding film 13 include a metal such as black resist or chromium.

  The first optical surface 11 is formed of an ultraviolet curable resin so as to cover the opening 13a and the light shielding film 13 on the outer peripheral side of the opening 13a. That is, the first optical surface 11 is arranged so that the peripheral edge overlaps the vicinity of the opening 13 a of the light shielding film 13. Thereby, the opening 13 a of the light shielding film 13 functions as a stop of the first optical surface 11.

  In the second optical element 2, a third optical surface 21 and a fourth optical surface 22 are formed on each surface of the second substrate 20 that transmits light. The third optical surface 21 is formed on a surface of the second substrate 20 facing the second optical surface 12 of the first optical element 1, and the fourth optical surface 22 is a sensor on the second substrate 20. It is formed on the surface facing the 3 side.

  A light shielding film 23 is formed on the surface of the second substrate 20 on which the third optical surface 21 is formed. The structure of the light shielding film 23 is the same as that formed in the first optical element 1, and has an opening 23 a that functions as a stop in the third optical surface 21.

  A filter film 24 is formed on the entire surface of the second substrate 20 on which the fourth optical surface 22 is formed. The filter film 24 is formed by forming a layer having a characteristic of transmitting visible light and not transmitting infrared light into a thin film, and by alternately laminating a layer of a low refractive index material and a layer of a high refractive index material. Composed.

  The first optical element 1 and the second optical element 2 are arranged so as to be opposed to each other with a predetermined distance therebetween via the first spacer 4. Further, the second optical element 2 and the sensor 3 are arranged so as to be opposed to each other with a predetermined distance therebetween via the second spacer 5. Thereby, the light from the outside is condensed on the sensor 3 by the first optical surface 11 to the fourth optical surface 22 of the first optical element 1 and the second optical element 2.

  Next, the manufacturing process of the first optical element 1 and the second optical element 2 will be described. FIG. 2 is a cross-sectional view showing the manufacturing process of the first optical element 1. FIG. 2A shows the first substrate 10, and a transparent glass substrate is prepared in this embodiment. In this manufacturing process, a large number of optical elements, which are finished products, are formed at one time, so a large glass substrate is prepared and a plurality of optical surfaces are formed in an array. The optical element is separated. However, in FIGS. 2 and 4, only one optical element is shown in a simplified manner.

  As shown in FIG. 2B, a mask 30 is formed on the surface of the first substrate 10. The mask 30 is formed in a region serving as a path of light passing through the first optical surface 11 and the second optical surface 12 and serving as the opening 13 a of the light shielding film 13. The mask 30 can be formed by a photolithography technique.

  When the mask 30 is formed in the predetermined region, roughening is performed on the surface of the first substrate 10 as shown in FIG. FIG. 3 is a schematic diagram showing the rough surface processing steps. In the present embodiment, the rough surface processing is performed using a wet blasting technique. Wet blasting is a method of increasing the surface roughness of a smooth surface by mixing a liquid such as water containing particulate abrasive with compressed air and injecting it into a target from a blast gun. .

  As shown in FIG. 3, with the mask 30 formed in an array on the large substrate 15 that is the first substrate 10, the outer edge portion of the large substrate 15 is fixed by the fixing chuck 40, and the surface of the large substrate 15 is fixed. On the other hand, a liquid such as water containing particulate abrasive in a mixed state and compressed air are jetted from the blast gun 41. Thereby, the surface roughness of the surface of the large substrate 15 other than the masked region is increased.

  When the rough surface processing is performed, the light shielding film 13 is formed on the surface of the first substrate 10 as shown in FIG. The light shielding film 13 is formed by vapor deposition, sputtering, or wet coating. Subsequently, as shown in FIG. 2E, the mask 30 is removed. As a result, the surface on which the first optical surface 11 is formed is in a state where the light shielding film 13 covers the region other than the region where the roughened light passes and the opening 13a is formed. Moreover, about the surface where the 2nd optical surface 12 is formed, it will be in the state by which the rough surface process was carried out except the area | region where light passes.

  The surface is thus roughened and an optical surface is formed on the first substrate 10 on which the light shielding film 13 is formed. As shown in FIG. 2F, the first optical surface 11 is formed on the surface of the first substrate 10 on which the light shielding film 13 is formed. The first optical surface 11 is made of light or a thermosetting resin, presses the resin material against the first substrate 10 with a mold, transfers the shape, and irradiates or heats light of a specific wavelength. It is formed by curing a resin material. Subsequently, as shown in FIG. 2G, the second optical surface 12 is formed on the opposite surface of the first substrate 10 by the same method.

  As described above, the surface of the first substrate 10 is roughened in a region other than the region through which light passes, so that the adhesion of the light shielding film 13 to the surface of the first substrate 10 can be increased. . Thus, as described above, after these steps, the first substrate 10 is separated by dicing, and the light shielding film 13 can be prevented from peeling off at that time. In the first optical element 1, the thin film is formed only on the first optical surface 11 side, but the roughening is performed on both surfaces of the first substrate 10. Thereby, the adhesiveness with respect to the 1st board | substrate 10 of the 2nd optical surface 12 can be improved, and peeling of the 2nd optical surface 12 can be prevented.

  FIG. 4 is a cross-sectional view showing the manufacturing process of the second optical element 2. Also for the second optical element 2, a transparent glass substrate is prepared as shown in FIG. 4A, and a mask 50 is formed on the surface of the second substrate 20 as shown in FIG. 4B. . The mask 50 is formed in a region that becomes a path of light passing through the third optical surface 21 and the fourth optical surface 22.

  Subsequently, as shown in FIG. 4C, the surface of the second substrate 20 is roughened. This rough surface processing is performed in the same process as described for the first optical element 1. When the rough surface processing is performed, as shown in FIG. 4D, a light shielding film 23 is formed on the surface of the second substrate 20 on which the third optical surface 21 is formed by vapor deposition, sputtering, or wet coating. Form. As shown in FIG. 4E, when the mask 50 is removed, an opening 23a is formed.

  Next, as shown in FIG. 4F, a filter film 24 is formed on the surface on which the fourth optical surface 22 of the second substrate 20 is formed by vapor deposition or sputtering. At this stage, since the mask is not formed on the surface on which the fourth optical surface 22 of the second substrate 20 is formed, the filter film 24 is formed over the entire surface.

  When thin films are formed on both surfaces of the second substrate 20, a third optical surface 21 is formed on the second substrate 20 as shown in FIG. 4G, and further shown in FIG. As described above, the fourth optical surface 22 is formed on the opposite surface. The formation of these optical surfaces is performed by the same method as the formation of the first optical surface 11 and the second optical surface 12 of the first optical element 1.

  As described above, the second optical element 2 also has high adhesion to the light shielding film 23 and the filter film 24 by roughening the surface of the second substrate 20 other than the region through which light passes. It is possible to prevent the thin film from being peeled off during dicing performed in the subsequent process.

  In this embodiment, a photolithography technique is used to form a mask on a substrate. However, when high accuracy is not required for the position and size of a masked region, that is, a region that is not roughened. Can also use a potting technique. In this case, a mask is formed by dropping a liquid as a mask material onto a predetermined position on the substrate and curing it. By using the potting technique, the cost can be reduced as compared with the case of photolithography.

  The method of forming a mask on a substrate by photolithography or potting requires a mask formation process and a removal process, which complicates the manufacturing process. For this reason, the mask may be formed by a mask member. FIG. 5 shows a conceptual cross-sectional view when masking is performed using the mask member 60. Also in this case, as in FIG. 3, the outer edge portion of the large substrate 15 is fixed by the fixed chuck 40. In addition, a mask member 60 having a covering portion 61 that is in contact with and covers a region through which light passes is attached to the large substrate 15. The mask member 60 includes a plurality of covering portions 61 connected by a connecting portion 62, and the surface roughness of the large substrate 15 other than the region covered by the covering portion 61 is increased by particles from the blast gun 41. Surface machining is performed. When the rough surface processing is performed, the mask member 60 can be removed from the large substrate 15 to remove the mask.

  In this way, by masking the region through which light passes through the mask member 60, the process of forming and removing the mask on the substrate can be simplified. Moreover, as a structure of the mask member 60, various forms are considered as follows. FIG. 6 shows a perspective view of the large substrate 15 masked by the mask member 60 of the second embodiment.

  As shown in FIG. 6, the mask member 60 of the second form has a large number of rods 66 erected on a disc-shaped base 65, and the tip surface of the rods 66 abuts against the large substrate 15 to form a predetermined region. The covering portion 67 is covered. The covering portion 67 is formed so as to cover a region through which light passes among the substrates formed on the large substrate 15.

  FIG. 7 shows a perspective view of the large substrate 15 masked by the mask member 60 of the third embodiment. The mask member 60 of the third embodiment is attached to the surface of the large substrate 15, and a plurality of covering portions 71 are formed in the outer edge portion 70 along the outer periphery of the large substrate 15. The covering portion 71 and the outer edge portion 70 are configured to be connected by an elongated connecting portion 72. The covering portion 71 is formed so as to contact the region through which light passes among the substrates formed on the large substrate 15 and cover the surface.

  In the mask member 60 of the present embodiment, the connecting portion 72 also covers the large substrate 15, but the connecting portion 72 is formed elongated, and the surface of the large substrate 15 other than the covering portion 71 and the connecting portion 72 is Since the rough surface is processed by the particles from the blast gun 41, the effect of the present invention can be sufficiently obtained.

  Although the embodiment of the present invention has been described above, the application of the present invention is not limited to this embodiment, and can be applied in various ways within the scope of its technical idea. In this embodiment, a lens is formed as an optical surface, but the optical surface may be any other optically functional surface such as a diffraction grating. Further, the thin film formed on the surface of the substrate is not limited to the light shielding film or the filter film, and may be any film that functions optically, such as an antireflection film or a reflection film.

DESCRIPTION OF SYMBOLS 1 1st optical element 2 2nd optical element 3 Sensor 4 1st spacer 5 2nd spacer 10 1st board | substrate 11 1st optical surface 12 2nd optical surface 13 Light-shielding film 20 2nd board | substrate 21 Third optical surface 22 Fourth optical surface 23 Light shielding film 24 Filter film 60 Mask member 61 Covering part 62 Connecting part 65 Base part 66 Rod 67 Covering part 70 Outer edge part 71 Covering part 72 Connecting part

Claims (5)

In an optical element in which an optical functional film and an optical surface are formed on a substrate that transmits light,
Of the surface of the substrate, a region other than a region through which light passing through the optical surface passes is roughened, and the optical functional film and the optical surface are formed on the surface of the substrate including the roughened region. An optical element formed by forming a film. In the method of manufacturing an optical element in which an optical functional film and an optical surface are formed on a substrate that transmits light,
A region of the surface of the substrate through which the light transmitted through the optical surface passes is covered with a mask, a region other than the region covered with the mask is roughened, and the mask is removed to roughen the surface. A method of manufacturing an optical element, comprising forming the optical functional film on the surface of the substrate including a region and forming an optical surface. In the method of manufacturing an optical element in which an optical functional film and an optical surface are formed on a substrate that transmits light,
A region of the surface of the substrate through which the light transmitted through the optical surface passes is covered with a mask, a region other than the region covered with the mask is roughened, and the surface of the substrate including the roughened region is included. A method of manufacturing an optical element, comprising forming the optical functional film on a surface, removing the mask, and forming an optical surface on the surface of the substrate.   4. The method of manufacturing an optical element according to claim 2, wherein the mask is formed by photolithography or potting.   The mask comprises a mask member that contacts a predetermined area of the substrate, covers the predetermined area by attaching the mask member to the substrate, and removes the mask by removing the mask member from the substrate after the rough surface processing. The method for manufacturing an optical element according to claim 2, wherein:

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