JP3778621B2 - Optical component coating method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for coating optical parts (for example, non-reflective coating), and in particular, a resin formed by resin molding using a molding die, using a plurality of identical optical elements or a plurality of different optical elements. The present invention relates to a coating method for a manufactured optical substrate.
[0002]
[Prior art]
Optical components such as a diffraction grating, a hologram element, and various lenses are manufactured by processing (etching or cutting and polishing) a glass substrate. However, in this manufacturing method, the manufacturing process is complicated and it is difficult to manufacture in large quantities, but in recent years, a manufacturing method by resin molding has been used. However, in the case of manufacturing by conventional molding, since it is molded by several units, it does not lead to a sufficient cost reduction.
[0003]
Therefore, the applicant of the present application forms a large number (for example, 1000 or more) of optical elements on a single resin substrate by molding once in Japanese Patent Application No. 8-77375, and then the resin substrate is formed into individual optical elements. Invented a manufacturing method that divides every time, making it possible to provide inexpensive optical components.
In general, optical components require a coating process, such as an anti-reflective coating.
[0004]
The coating process of the optical component is generally performed by a vacuum deposition apparatus. In order to increase the adhesion between the surface of the optical component and the coating layer, a certain temperature is required for the deposition. In order to obtain sufficient adhesion, a temperature environment of about 300 ° C. is required.
[0005]
[Problems to be solved by the invention]
However, resin optical parts need to be processed at a low temperature (for example, around 100 ° C.). Otherwise, the resin itself is thermally deformed. For this reason, if the treatment is performed at a low temperature, there is a disadvantage that the adhesion between the resin surface and the coating layer is weakened.
[0006]
Therefore, when the optical component is divided by a dicing machine or the like after the coating process, a defect that the coating layer is peeled off or chipped from the edge portion of each optical element occurs, and the effectiveness of the effect by the coating process is hindered.
The present invention has been made for the purpose of providing a coating method that does not impair the effect of the coating treatment of the optical element.
[0007]
[Means for Solving the Problems]
The present invention has been made to solve such a problem, and the invention according to claim 1 is a method for coating a resin optical substrate in which a plurality of optical elements are formed by resin molding using a molding die. The resin optical substrate is made of a thermoplastic resin, and a portion for dividing a plurality of optical elements formed on the resin optical substrate made of the thermoplastic resin into individual optical elements is masked. , when applying a coating process to the optical element, the resin optical substrate characterized in that it is held at a temperature lower than the heat deformation temperature.
The invention according to claim 2 is a method of coating a resin optical substrate in which a plurality of optical elements are formed by resin molding using a molding die, wherein the resin optical substrate is a polycarbonate as a thermoplastic resin. And masking portions for dividing the plurality of optical elements formed on the resin optical substrate made of the thermoplastic resin into individual optical elements, and applying the coating treatment to the optical elements, the resin Ltd. optical substrate is characterized by Rukoto held in Celsius to about 100 degrees is a lower temperature than the thermal deformation temperature.
[0008]
Further, the invention according to claim 3 is a coating method of a resin optical substrate in which a plurality of optical elements are formed by resin molding using a molding die, and the resin optical substrate is made of a thermoplastic resin. When the optical element is subjected to a coating treatment by masking a portion for dividing the plurality of optical elements formed on the resin optical substrate made of the thermoplastic resin into individual optical elements, the resin optical The substrate is held at a temperature lower than its thermal deformation temperature,
The optical element, a diffraction grating, the hologram element, a Fresnel lens, wherein the anti-reflective coating process is performed on the optical element.
[0009]
Embodiment
1 is a schematic sectional view showing an example of masking for explaining the coating method of the present invention, FIG. 2 is a front view of an optical substrate manufactured by resin molding, and FIG. 3 is a masking for masking the optical substrate. 4 is a front view showing an example of a jig, FIG. 4 is a schematic diagram showing division of an optical substrate after coating processing into optical elements, and FIG. 5 is a typical vacuum deposition apparatus for explaining a coating method of optical components. It is a model diagram which shows the electron beam vapor deposition apparatus.
[0010]
FIG. 1 shows a cross-section when an optical substrate 1 made of a thermoplastic resin rich in optical properties such as polycarbonate and acrylic is masked by a masking jig 2. In Figure 1, the thermoplastic composed of a resin optical substrate 1 on one side surface (although one side or on both sides in this embodiment), the diffraction grating by resin molding, the hologram element, an optical element 1a such Fresnel lens is more Individually formed. FIG. 2 is a front view of such an optical substrate 1. In this embodiment, for example, a large number of optical elements 1a are formed on a disc-shaped optical resin substrate 1. FIG.
[0011]
The masking jig 2 shown in FIG. 3 can be coated on the surface of an area slightly larger than the portion where the optical element 1a is formed, for example, by using a metal masking jig 2 in a square shape by a photolithography technique or pressing. Opened opening 2a is formed. After such a masking jig 2 is brought into close contact with the resin optical substrate 1, the exposed surface of the resin optical substrate 1 is subjected to a vapor deposition process by an electron beam vapor deposition apparatus as shown in FIG. A coating layer 3 for antireflection coating is formed on the exposed surface of 1a.
[0012]
A specific coating method using a typical electron beam evaporation apparatus will be described with reference to FIG. The optical substrate 1 to be surface-coated is set in a vacuum furnace 6 equipped with a vacuum system 10 capable of creating a vacuum state of 10 −5 (10 to the fifth power) torr or less with its coating surface facing downward. The vaporized coating material 7, for example, magnesium fluoride (MgF 2), silicon dioxide (SiO 2), and cesium dioxide (CeO 2) is placed in a water-cooled crucible 11 at the bottom of the vacuum kiln 6.
[0013]
The optical substrate 1 is set in a carousel mount 8 that is installed so that each substrate is swept with a vaporized coating material that averages the same amount in time in the vacuum kiln 6. The carousel mount 8 is rotated by a rotation drive motor 9. The coating material 7 is irradiated with an electron beam by a high-density electron beam gun (not shown), and melted and vaporized by intense partial heating. The quartz lamp 12 for heating is for controlling the temperature inside the vacuum furnace 6 so that most of the vaporized vapor can be in an atomic or molecular state.
[0014]
Of course, the optical substrate 1 is also heated by the quartz lamp 12 at the time of vapor deposition, but the optical substrate 1 is kept at a temperature lower than the thermal deformation temperature (deflection temperature under load) determined by the resin material. In this embodiment, polycarbonate having a thermal deformation temperature (deflection temperature under load) of 120 to 140 degrees Celsius is used as the thermoplastic resin, and the temperature of the optical substrate 1 is kept at a low temperature of about 100 degrees Celsius, such as 100 to 110 degrees Celsius. The coating process was performed.
[0015]
As described above, since the coating material 7 is vaporized and the inside of the vacuum furnace 6 is decompressed with a high vacuum, a free path of free atoms or molecules is created, so that heavy steam also rotates at the top of the vacuum furnace 6. The coating material 7 that has reached the optical substrate 1 and is vaporized forms a uniform coating layer 3 on the surface of the optical substrate 1 and is condensed into a solid state.
[0016]
The film thickness of the coating layer 3 is controlled by optically monitoring the thickness of the coating layer formed on the monitor substrate 13 using a monitor beam and a photodetector (not shown).
The shutter 14 is for opening and closing when a necessary coating material is deposited when performing multilayer coating.
[0017]
By the coating method using the masking technique as described above, the coating layer 3 can be formed at a low temperature without causing thermal deformation so as to cover the optical element 1a as shown in FIG. The resin optical substrate 1 is divided by a dicing saw into individual optical elements of several square mm along the coating line 4 after the coating process. Since the part to be cut does not have the coating layer 3 formed by low temperature coating, the coating layer 3 is not peeled off or chipped by division with a dicing saw or the like, and the characteristic deterioration of the effect due to the coating process can be prevented. It is.
[0018]
In this embodiment, the coating layer 3 is coated only on the side of the optical substrate 1 on which the optical element 1a is formed, but the opposite surface is coated as necessary using the same masking jig 2. Alternatively, vacuum evaporation by resistance heating, sputtering, or chemical vapor deposition (CVD) may be used.
[0019]
【The invention's effect】
As described above, according to the coating method of the present invention, when a resin optical substrate made of a thermoplastic resin is divided into a plurality of optical elements, peeling or chipping of the coating layer due to such division is not caused. Thus, a large number of optical elements subjected to highly reliable coating processing can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a coating method of the present invention.
FIG. 2 is a front view of an optical substrate manufactured by resin molding and coated by the coating method of the present invention.
FIG. 3 is a schematic diagram showing a masking jig for masking an optical substrate used in the coating method of the present invention. FIG. 4 shows that an optical substrate coated with an optical substrate is coated by the coating method of the present invention. It is a model diagram which shows a division | segmentation.
FIG. 5 is a schematic diagram showing an example of a typical electron beam evaporation apparatus for performing a coating process on an optical component.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Resin optical board 1a Optical element 2 Masking jig 2a Opening part 3 Coating layer 4 Cutting line 6 Vacuum kiln 7 Coating material 8 Mount 10 Vacuum system 12 Quartz lamp for heating

Claims (3)

  A resin optical substrate coating method in which a plurality of optical elements are formed by resin molding using a molding die, wherein the resin optical substrate is made of a thermoplastic resin, and the resin optical substrate is made of the thermoplastic resin. The resin optical substrate is held at a temperature lower than its thermal deformation temperature when the optical element is subjected to a coating process by masking portions for dividing the optical elements formed on the optical substrate into individual optical elements. A method for coating an optical component. A resin optical substrate coating method in which a plurality of optical elements are formed by resin molding using a molding die, wherein the resin optical substrate uses polycarbonate as a thermoplastic resin , and is made of the thermoplastic resin. When a portion for dividing a plurality of optical elements formed on a resin optical substrate into individual optical elements is masked and the optical element is subjected to a coating process, the resin optical substrate has a temperature lower than its thermal deformation temperature. coating method of the optical component, characterized in Rukoto held at about 100 degrees Celsius is. A resin optical substrate coating method in which a plurality of optical elements are formed by resin molding using a molding die, wherein the resin optical substrate is made of a thermoplastic resin, and the resin optical substrate is made of the thermoplastic resin. The resin optical substrate is held at a temperature lower than its thermal deformation temperature when the optical element is subjected to a coating process by masking portions for dividing the optical elements formed on the optical substrate into individual optical elements. And
The optical element, a diffraction grating, the hologram element, a Fresnel lens, a coating method of an optical component, characterized in that non-reflection coating treatment is performed on the optical element.

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