JP2007334087A - Method of manufacturing optical component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an optical component having an excellent optical characteristic even after being formed with an optical thin film without expending considerable man-hours. <P>SOLUTION: Adjustment of the relative position between an outer side support part 10 and a center side support part 8 which are disposed on a fixture plate 7 is performed by adjusting a distance between the outer side support part 10 and the center side support part 8. The adjustment is performed on the basis of the fixture plate 7 and therefore the adjustment can be performed arbitrarily in a fine unit, even to a fine distance and with excellent reproducibility. As a result, a deformation applied to a base plate 2 can be also arbitrarily adjusted in a fine unit, even to a fine distance and with excellent reproducibility. In a method of forming the optical thin film 3, thermal expansion of base plate 2 and residual stress of the optical thin film 3 get to a subtly different value for different base plate depending on the distance and angle between the base plate 2, and a material source of the optical thin film 3 and a heating source or the like of the base plate 2. In the invention, the adjustment is performed for each base plate 2 and therefore subtle adjustment can be also performed in accordance with such a thermal expansion or residual stress. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an optical component in which an optical thin film is formed on a substrate.

  In an elastic optical body (hereinafter referred to as a substrate) having a vapor-deposited film as an optical thin film, the surface on which the optical thin film is formed on the substrate in the opposite direction in advance is concave or A technique for solving the problem of warping of the substrate due to internal stress by polishing the convex surface has been disclosed (see, for example, Patent Document 1).

JP-A-58-113901 (1st, 2nd page, Fig. 3)

However, it is necessary to polish each substrate in the opposite direction in advance in the opposite direction as much as the amount of warpage due to the internal stress of the optical thin film, and this processing takes a lot of man-hours.
The present invention has been made in view of the above points, and an object of the present invention is to provide a method for manufacturing an optical component having excellent optical characteristics even after the formation of an optical thin film without taking a great deal of man-hours. .

In order to achieve the above-described object, the optical component manufacturing method of the present invention uses the optical thin film formation surface as a reference surface based on the result of grasping the warp that occurs when the optical thin film is formed on the substrate. A pre-deformation step of deforming the substrate so that the formation surface is substantially plane-symmetrical with respect to the reference surface, and the optical thin film is formed on the substrate with the deformation applied And a thin film forming step.
According to the present invention, before forming the optical thin film, the warp caused by the formation of the optical thin film is a simple technique of applying deformation to the substrate so that the warp is substantially plane symmetrical. It is possible to generate stress in the opposite direction that is suspended by internal stress due to the thin film formation conditions and the influence of the optical thin film.
As a result, it is possible to provide a method of manufacturing an optical component having excellent optical characteristics without taking a great deal of man-hours.
The influence of the thin film formation condition is an influence of thermal expansion due to an increase in the substrate temperature, and the influence of the optical thin film is an influence of residual stress of the optical thin film.

In the present invention, a jig is used to apply the deformation, and the jig includes a flat jig plate, and the jig plate is provided with an outer support portion and a center support portion. The outer support portion is brought into contact with the outer peripheral portion of the substrate, the central support portion is brought into contact with the central portion of the substrate, and the outer support portion and the central support portion are It is preferable to apply the deformation to the substrate by adjusting the position.
In the present invention, the relative position between the outer support portion and the center support portion provided on the jig plate is adjusted by adjusting the distance between the outer support portion and the center support portion. Since this adjustment is performed using the jig plate as a reference, it can be arbitrarily adjusted with a minute unit and a minute distance with good reproducibility. As a result, the deformation applied to the substrate can be arbitrarily adjusted in minute units, with a very small amount, with good reproducibility.
In the method of forming an optical thin film, the thermal expansion of each substrate and the residual stress of the optical thin film are slightly different depending on the distance and angle between the substrate and the material source of the optical thin film, the heating source of the substrate, and the like. In the present invention, since adjustment is performed for each substrate, it is possible to make fine adjustments according to the thermal expansion and residual stress.

In the present invention, it is preferable that a bonding layer having a pressure-sensitive adhesive layer or an adhesive layer is provided at the tip of the central support portion, and the bonding layer is in contact with the substrate.
In the present invention, it is not necessary to process the substrate for contact between the central support portion and the central portion of the substrate, and the central support portion and the central portion of the substrate can be easily contacted and separated.

In the present invention, it is preferable that a joining member and a joining pair member that are joined by a magnetic force provided at a distal end portion of the support portion on the center side are arranged to face each other with the substrate interposed therebetween, and are brought into contact with the substrate. .
In the present invention, it is not necessary to process the substrate for contact between the central support portion and the central portion of the substrate, and the central support portion and the central portion of the substrate can be easily contacted and separated.

In the present invention, a contact member is provided at a distal end portion of the center side support portion, a hole is provided in the center portion of the substrate, and the center side support portion is inserted into the hole, The contact member is preferably brought into contact with the surface of the substrate.
In this invention, when the substrate is relatively small in shape, thick, when the rigidity of the substrate is large, or when the stress of the optical thin film is large, a relatively large physical force is required to deform the substrate in advance. As in the case where a small physical force is sufficient, the deformation can be made reliably, accurately and with good reproducibility.

Hereinafter, an embodiment according to a manufacturing method of an optical thin film filter 1 as an optical component of the present invention will be described with reference to the drawings.
(First embodiment)

FIG. 1 is a cross-sectional view showing an optical thin film filter 1 obtained in this embodiment.
In FIG. 1, an optical thin film filter 1 is composed of a substrate 2 that transmits light and an optical thin film 3 formed on one surface of the substrate 2.
The substrate 2 may be any material having excellent light transmission properties, such as plastic such as acrylic resin and polycarbonate resin, BK7, sapphire glass, borosilicate glass, white plate glass, blue plate glass, SF3, and SF7. In general, commercially available optical glass can be used, and quartz may also be used.
The planar shape of the substrate 2 may be rectangular or circular, and the front and back surfaces of the substrate 2 may be flat or curved, and the front and back surfaces of the substrate 2 are non-parallel even if they are parallel to each other. A parallel relationship may be used.
The optical thin film 3 is composed of one or more dielectrics, for example, a dielectric layer in which first and second materials having different refractive indexes are alternately stacked. And it is 1 or more types chosen from an anti-reflective film, UV-IR cut film (Ultraviolet-Infrared cut), or IR cut (Infrared cut) film | membrane.
The optical thin film 3 may be formed on both surfaces of the substrate 2.

Next, the manufacturing method of the optical thin film filter 1 of this embodiment is demonstrated.
FIG. 2 is a process diagram showing a method for manufacturing the optical thin film filter 1 of the present embodiment.
3, 4 (a) and 4 (b) are cross-sectional views showing the grasping of the warpage.
FIG. 5 is a cross-sectional view showing the deformation jig 6 used in the preliminary deformation process.
6A and 6B are cross-sectional views showing a pre-deformation step.
7A and 7B are cross-sectional views showing a thin film forming process.
FIG. 8 is a partial cross-sectional view of the vicinity of the distal end portion 17 of the support portion 8 on the center side in the pre-deformation process of the present embodiment.

As shown in FIG. 2, the manufacturing method of the optical thin film filter 1 of this embodiment has the pre-deformation process and thin film formation process based on the grasp of the curvature, and the result.
The warp after the formation of the optical thin film 3 varies depending on the material and shape of the substrate 2, the material and thickness of the optical thin film 3, the thin film formation conditions, and the like. Therefore, when these conditions do not change, it is not always necessary to grasp the warp.

FIG. 3 shows the flat placing jig 4 and the substrate 2 used for grasping the warpage.
In grasping the warp, the optical thin film 3 is formed on the formation surface 5 which is one side of the substrate 2 arranged in the flat placing jig 4 shown in FIG.
Here, the substrate 2 may be a substrate for one optical filter 1 or a substrate for dividing the substrate 2 later to obtain a plurality of optical filters 1.
As a forming method, a vapor deposition method, an ion assist vapor deposition method, an ion plating method or a sputtering method can be used. A material source is an oxide such as SiO ₂ or TiO ₂ , a fluoride such as MgF ₂ or CaF _2, or a ZnS material. Such sulfides and halides such as KI and NaBr can be used. Note that the position of the material source is on the lower side of the substrate 2 in FIG.
The state after formation of the optical thin film 3 is shown in FIG. 4A and 4B, the substrate 2 warps with a warp width A or a warp width B depending on whether the internal stress due to the thin film formation conditions or the influence of the optical thin film 3 is compression or tension.

In the preliminary deformation step, the deformation jig 6 shown in FIG. 5 is used as the jig. In FIG. 5, the deformation jig 6 includes a flat jig plate 7, and the flat jig plate 7 includes a support portion 8 on the center side of the jig and a support portion 10 on the outside of the jig. Is provided. The outer support portion 10 includes a receiving plate 11 and a pressing plate 12.
In addition, a distance adjustment fixing portion 9 is provided for determining and fixing the position of the support portion 8 on the center side with respect to the integrated jig plate 7 and the outer support portion 10.

Hereinafter, the pre-deformation step will be described separately for the warp widths A and B after the formation of the optical thin film 3.
In the case of FIG. 4A having a warp width A, the receiving plate 11 of the deformation jig 6 is brought into contact with the outer peripheral portion 16 of the substrate 2 as shown in FIG. The support portion 8 on the center side is brought into contact with 15. Then, the first reference point 14 of the outer support 10 and the second reference of the center support 8 are moved by moving the center support 8 in the direction of the arrow by a distance corresponding to the warp width A. The distance to the point 13 is adjusted, the substrate 2 is deformed, and then the center side support portion 8 is fixed by the distance adjustment fixing portion 9.
In the case of FIG. 4B having a warp width B, as shown in FIG. 6B, the pressing plate 12 of the deformation jig 6 is brought into contact with the outer peripheral portion 16 of the substrate 2 and the center portion of the substrate 2 is placed. The support portion 8 on the center side is brought into contact with 15. Then, the first reference point 14 of the outer support 10 and the second reference of the center support 8 are moved by moving the center support 8 in the direction of the arrow by a distance corresponding to the warp width B. The distance to the point 13 is adjusted, the substrate 2 is deformed, and then the center side support portion 8 is fixed by the distance adjustment fixing portion 9.
As described above, in the preliminary deformation step, the formation surface 5 of the optical thin film 3 is used as a reference surface, and the formation surface 5 of the optical thin film 3 of the substrate 2 is substantially plane-symmetric with respect to the reference surface. In order to achieve this, the substrate is deformed.

  In the thin film forming step, the optical thin film 3 is formed on the formation surface 5 of the substrate 2 as shown in FIGS. 7A and 7B, corresponding to FIGS. 6A and 6B, respectively. The thin film formation method, thin film formation conditions, and the like are the same as those described in grasping the warpage.

Here, contact, fixing, and separation between the support portion 8 on the center side and the center portion 15 of the substrate 2 will be described in detail with reference to FIG. A bonding layer 18 having a pressure-sensitive adhesive or an adhesive is provided at the distal end portion 17 of the support portion 8 on the center side.
Since the amount of deformation to be applied to the substrate 2 is generally a small amount, the fixing force may be small.
From the above, there is no particular restriction on the material of the pressure-sensitive adhesive or adhesive, and acrylic or vinyl-based pressure-sensitive adhesives or acrylic-based, epoxy-based or polyimide-based adhesives can be used, and the amount used may be small. .

In the case where the bonding layer 18 has an acrylic or vinyl-based pressure-sensitive adhesive, the fixing by contact between the support 8 on the center side and the substrate 2 and after the pressure-sensitive adhesive shrinks by UV (Ultraviolet) irradiation to the bonding layer 18. In the separation of the support portion 8 on the center side and the substrate 2, contact, fixation and separation can be achieved with a small force.
When the bonding layer 18 has an adhesive such as acrylic, epoxy, or polyimide, UV (ultraviolet) irradiation or heating is performed on the bonding layer 18 after the contact between the support portion 8 on the center side and the substrate 2. The adhesive is cured, and the support portion 8 on the center side and the substrate 2 are fixed.
As for the separation, a heat shock is applied in a state where the deformation jig 6 and the substrate 2 are integrated, and the support portion 8 on the center side and the substrate 2 are separated.
This contact, fixation and separation can both be achieved with very little force.

  When a plurality of optical filters 1 are obtained, the substrate 2 is appropriately divided after the thin film forming step.

Incidentally, the heat shock refers to, for example, immediately leaving it at a room temperature or lower after holding it at 80 ° C. or higher for a certain time.
Although not shown in FIG. 8, the optical thin film 3 is formed on the substrate 2 at the time of separation between the support portion 8 on the center side and the substrate 2.
Further, when the substrate 2 is deformed in advance in the direction as shown in FIG. 6B, the bonding layer 18 may be omitted.
As described above, the optical thin film filter 1 with less warpage can be obtained.

Hereinafter, effects of the first embodiment will be described.
(1) Before the optical thin film 3 is formed, the surface 5 on which the optical thin film 3 is formed can be obtained by a simple technique in which the substrate 2 is deformed so that the warp caused by the formation of the optical thin film 3 is substantially plane symmetrical. In addition, it is possible to generate a stress in the opposite direction that is suspended by the internal stress due to the thin film formation conditions, the influence of the optical thin film 3, or the like.
Thereby, the manufacturing method of the optical component which has the outstanding optical characteristic can be provided, without spending a lot of man-hours.
(2) The relative position between the outer support 10 and the center support 8 provided on the jig plate 7 is adjusted, and the distance between the outer support 10 and the center support 8 is adjusted. To do. Since this adjustment is performed using the jig plate 7 as a reference, it can be arbitrarily adjusted in minute units up to a minute distance with good reproducibility. As a result, the deformation applied to the substrate 2 can be arbitrarily adjusted to a very small amount with a high reproducibility.
In the method of forming the optical thin film 3, the thermal expansion of each substrate 2 and the residual stress of the optical thin film 3 differ slightly depending on the distance and angle between the substrate 2 and the material source of the optical thin film 3, the heating source of the substrate 2, and the like. It becomes. In the present invention, since the adjustment is performed for each substrate 2, a delicate adjustment according to the thermal expansion and residual stress can be performed.
(3) Processing to the substrate 2 for contact between the center side support portion 8 and the center portion 15 of the substrate 2 is not required, and the center side support portion 8 and the center portion 15 of the substrate 2 are easily contacted and separated. it can.
(Second Embodiment)

The second embodiment differs only in the way of contact between the central support portion 8 and the central portion 15 of the substrate 2 of the first embodiment.
Thus, only different points will be described, and description of the same contents as in the first embodiment will be omitted.

  FIG. 9 is a partial cross-sectional view of the vicinity of the distal end portion 17 of the support portion 8 on the center side in the pre-deformation process of the present embodiment.

In FIG. 9, a support member on the center side is formed by placing a joining member 19 and a joining pair member 20 that are joined to each other by a magnetic force provided at the tip portion 17 so as to face each other with the substrate 2 interposed therebetween. 8 and the central portion 15 of the substrate 2 are brought into contact with each other.
Here, both the joining member 19 or the joining pair member 20 are magnets, or one is a magnet and the other is a magnetic body.
A permanent magnet such as a ferrite magnet or a neodymium magnet can be used as the magnet, and pure iron, permalloy, sendust alloy, or the like can be used as the magnetic material, and nickel corrosion-resistant plating is performed as necessary.
In general, fixing is performed by utilizing a magnetic force of a permanent magnet and a magnetic material that are widely used, and both contact, fixation, and separation can be achieved with a small force.
When the substrate 2 is deformed in advance in the direction as shown in FIG. 6B, the bonding member 20 may not be provided.

Hereinafter, effects of the second embodiment will be described.
(4) It is not necessary to process the substrate 2 for contact between the central support portion 8 and the central portion 15 of the substrate 2, and the central support portion 8 and the central portion 15 of the substrate 2 can be easily contacted and separated. it can.
(Third embodiment)

The third embodiment is different from the first embodiment and the second embodiment in the manner of contact between the support portion 8 on the center side and the center portion 15 of the substrate 2. Specifically, a hole 24 is provided in the substrate 2 and is fixed using the hole 24.
Thus, only different points will be described, and description of the same contents as those in the first and second embodiments will be omitted.

FIG. 10A is a plan view showing processing for providing the holes 24 in the substrate 2, and FIG. 10B is a sectional view taken along the line CC of FIG.
FIGS. 11A and 11B are partial cross-sectional views in the vicinity of the distal end portion 17 of the support portion 8 on the center side in the pre-deformation step of the present embodiment.

The hole 24 can be provided in the substrate 2 by a chemical method or a mechanical method.
10A and 10B, a corrosion-resistant film 22 is formed on the surface of the substrate 2 by a sputtering method, and a resist film 23 is formed in addition to the drilling target portion 21. The corrosion resistant film 22 has a Cr film and an Au film.
Next, Au in the target hole 21 is dissolved and removed with an etching solution containing I ₂ and KI as main components and Cr with an etching solution containing ceric ammonium nitrate as a main component.
Next, the holes in the substrate 2 are chemically treated with a chemical solution for etching the substrate 2 (a potassium hydroxide aqueous solution when the substrate is glass, or a mixed solution of a hydrogen fluoride aqueous solution and an ammonium fluoride aqueous solution when quartz is used). The target location 21 is dissolved and removed, and then the resist film 23 is removed with a resist stripping solution.
As another method, it is also possible to perform mechanical drilling by an ultrasonic drilling method.

Hereinafter, the contact methods will be described separately for the cases of warp widths A and B after the formation of the optical thin film 3 in FIG.
In the case of the warp width A, in FIG. 11A (assuming that the substrate 2 is deformed in the same direction as FIG. 6A), the central support portion 8 provided with the contact member 25 at the tip portion 17 is the substrate. Then, the contact member 25 is brought into contact with the surface of the substrate 2 (the lower surface on the paper surface).
In the case of the warp width B, in FIG. 11 (b) (assuming that the substrate 2 is deformed in the same direction as FIG. 6 (b)), the support portion 8 on the center side provided with the contact member 25 at the tip portion 17 is the substrate. The contact member 25 is brought into contact with the surface of the substrate 2 (the upper surface on the paper surface).

Hereinafter, effects of the third embodiment will be described.
(5) When the substrate 2 is relatively small in shape, thick, when the rigidity of the substrate 2 is large, or when the stress of the optical thin film 3 is large, a relatively large physical force is required to deform the substrate 2 in advance. As in the case where a relatively small physical force is sufficient, the deformation can be reliably and accurately performed with good reproducibility.

Hereinafter, the present invention will be described in more detail based on examples.
Example 1

This example has good reflection characteristics that transmit light in the visible wavelength range, and absorb less light in the ultraviolet wavelength range below the predetermined wavelength and in the infrared wavelength range above the predetermined wavelength, and the substrate 2 is made of quartz. This is an example applied to the optical thin film filter 1 (UV-IR cut filter) having an optical low-pass filter function.
Matters related to the grasping of the substrate 2, the optical thin film 3, the warp, and the contact, fixing and separation between the support portion 8 on the center side and the center portion 15 of the substrate 2 are as described below, and others are the first embodiment. And the same.

As the substrate 2, a quartz plate having a diameter of 45 mm (refractive index n = 1.52) and a thickness of 0.43 mm was used.
As a method of forming the optical thin film 3, a normal vapor deposition method was used.
As the optical thin film 3, TiO ₂ (refractive index n = 2.40), which is a high refractive material (H), and SiO ₂ (refractive index n = 1.46), which is a low refractive index material (L), are formed on one surface of the substrate 2. ) Are alternately laminated.

Details of the film configuration of the optical thin film 3 will be described.
In the description of the film thickness configuration described below, the film thickness of the high refractive index material layer (H) is expressed as 1H for the value of the optical film thickness nd = 1 / 4λ, and the low refractive index material layer (L) is similarly described. Indicated as 1L. In addition, the notation of S in (xH, yL) ^S represents that the configuration in parentheses is periodically repeated by the number of repetitions called the number of stacks.
The optical thin film 3 has a thickness of 550 nm, a design wavelength λ of 550 nm, a high refractive index material TiO ₂ film 3H1 of the upper surface first layer of the substrate 2 of 0.60H, and a second layer of low refractive index material SiO ₂ film 3L1. Is 0.20L, and subsequently 1.05H, 0.37L, (0.68H, 0.53L) ⁴ , 0.69H, 0.42L, 0.59H, 1.92L, (1.38H, 1. 38L) ⁶ , 1.48H, 1.52L, 1.65H, 1.71L, 1.54H, 1.59L, 1.42H, 1.58L, 1.51H, 1.72L, 1.84H, 1. 80L, 1.67H, 1.77L, (1.87H, 1.87L) ⁷ , 1.89H, 1.90L, 1.90H, the top layer of the low refractive index material SiO ₂ film 3L30 is 0.96L A total of 60 layers were formed.

Next, the grasp of warpage will be described.
In the substrate 2 on which the optical thin film 3 is formed, the formation surface 5 of the optical thin film 3 becomes convex due to the strong compressive stress of SiO ₂ of the low refractive index material layer and the weak tensile stress of TiO ₂ of the high refractive index material layer. In addition, it was grasped that a warp with a warp width A occurred.
Therefore, in the pre-deformation step, based on the result of grasping the warp, the formation surface 5 of the optical thin film 3 is used as a reference surface, and the formation surface 5 of the optical thin film 3 is substantially plane-symmetric with respect to the reference surface. The substrate 2 was deformed so as to be warped.

Next, contact, fixation, and separation between the support portion 8 on the center side and the center portion 15 of the substrate 2 will be described.
To the bonding layer 18 at the tip 17 of the support portion 8 on the center side, a base portion of a UV curable dicing tape (model number: Adwill D-638, manufacturer: Lintec Co., Ltd.) is bonded with an epoxy adhesive on both sides. The tape which used this as the adhesive layer was used.
The above-mentioned pressure-sensitive adhesive layer is made of a UV curable acrylic pressure-sensitive adhesive, and the pressing and pressing of the pressure-sensitive adhesive layer is sufficient for contact and fixing, and no special treatment is required.
Separation was performed after the adhesive strength was weakened by irradiating the bonding layer 18 with UV (main wavelength 365 nm, illuminance 220 mw / cm ₂ , light quantity 160 mJ / cm ₂ ).
The pressure-sensitive adhesive layer did not remain on the separated substrate 2 at a level causing a practical problem.

  Table 1 shows the measurement results of the warpage width of the substrates (two pieces of No1 and No2 in each jig) in this example. The warping width is such that the formation surface 5 other than the outer peripheral portion 15 of the substrate 2 has the formation surface 5 of the optical thin film 3 up and the outer peripheral portion 15 of the formation surface 5 of the optical thin film 3 of the substrate 2 is zero reference. A case where it is on the upper side due to warpage is represented by a positive value, and a case where it is on the lower side is represented by a negative value, and its unit is μm. And the measurement of the curvature width used the high precision flatness tester FT-900 (made by Nidec Co., Ltd.).

  As described above, the optical thin film filter 1 (UV-IR cut filter) having an optical low-pass filter function composed of a single crystal plate with less warpage can be produced.

  Next, in order to evaluate optical characteristics, a laminated optical low-pass filter using a plurality of quartz plates including the optical thin film filter 1 (UV-IR cut filter) was produced.

FIG. 12 is a cross-sectional view showing a laminated optical low-pass filter 30.
FIG. 13 is a schematic diagram showing the optical axis of the laminated optical low-pass filter 30 and the traveling direction of the light beam.

As shown in FIG. 12, the laminated optical low-pass filter 30 includes two crystal plates 40 and 50 as birefringent plates and a quarter-wave plate 60. , 50 also has a three-layer structure in which a quarter-wave plate 60 made of quartz is inserted.
The quartz plate 40 is the optical thin film filter 1 in which the above-described substrate is made of quartz, and an optical thin film is formed on one surface of the quartz plate 40. The quartz plate 40, the quarter-wave plate 60, and the quartz plate 50 constituting the three-layer structure are bonded together to form an integral structure.

For the quartz plate 40, an optical thin film filter shown in Table 1 that uses the deformation jig 6 of FIG. 5 at the time of thin film formation and the flat placement jig 4 of FIG. A laminated optical low-pass filter 30 constituting a three-layer structure was produced. The former is called an evaluation optical low-pass filter, and the latter is called a comparative optical low-pass filter.
Two optical thin film filters, No. 1 and No. 2 in each jig shown in Table 1, are used, and the applied optical low-pass filter is also No. 1 and No. 2 correspondingly.
Table 2 shows the measurement result of the transmitted wavefront aberration value of each laminated optical low-pass filter 30.
The measurement was performed using a laser interferometer.

Here, the optical axis of the laminated optical low-pass filter 30 and the traveling direction of the light beam will be described with reference to FIG.
The crystal plate 40 arranged on the light incident side is a direction (indicated by an arrow A1) that forms an azimuth angle of about 45 degrees with the z axis on a plane (xz plane) that is orthogonal to the light incident surface and parallel to the paper surface. Direction) with an optical axis (optical principal axis). The light beam L1 incident on the crystal plate 40 is separated into two light beams L11 and L12 and emitted by the birefringence of the crystal plate 40. These light beams L11 and L12 are emitted with their deflection states changed to linear deflection.
The quarter-wave plate 60 has an optical axis in a direction (direction indicated by an arrow A2) that forms an azimuth angle of about 45 degrees with the x-axis on the light incident surface (xy plane). As a result, the light beams L11 and L12 incident on the quarter-wave plate 60 are changed from a linear deflection to a circular deflection, and are emitted as two light beams L13 and L14.
The crystal plate 50 arranged on the light emitting side has a direction (indicated by an arrow A3) that forms an azimuth angle of about 45 degrees with the y axis on a plane (yz plane) that is orthogonal to the light incident surface and orthogonal to the paper surface. Direction). The light beam L13 incident on the crystal plate 50 is separated into two light beams L15 and L16 and emitted by the birefringence of the crystal plate 50. The light beam L14 incident on the quartz plate 50 is separated into two light beams L17 and L18 and emitted as in the quartz plate 40. These light beams L15, L16, L17, and L18 are emitted with their deflection states changed to linear deflection.

Next, the laminated optical low-pass filter 30 constituting the above-described three-layer structure is an imaging module in which the imaging element and the drive unit are integrated, and the imaging module is further incorporated in a digital still camera to take a picture of a landscape or a person, The image was confirmed visually. In the case of using the evaluation optical low-pass filter and the case of using the comparative optical low-pass filter, it was confirmed that the former was clear and the latter was blurred.
(Example 2)

This embodiment is an example applied to an optical thin film filter 1 (IR cut filter) that transmits light in the visible wavelength region and has good reflection characteristics with little light absorption in the infrared wavelength region of a predetermined wavelength or more. is there.
Matters relating to the grasp of the substrate 2 and warping are as described below, and the others are the same as those in the first embodiment.

As the substrate 2, a glass plate having a diameter of 45 mm (refractive index n = 1.52) and a thickness of 0.3 mm was used.
As a method of forming the optical thin film 3, a normal vapor deposition method was used.
The optical thin film 3 was formed by alternately laminating TiO ₂ as a high refractive index material (H) and MgF ₂ as a low refractive index material layer (L) on one surface of the substrate 2.

Details of the film configuration of the optical thin film 3 will be described.
The film thickness of the optical thin film 3 is such that the design wavelength λ is 755 nm, 1.14H, 1.09L, 1.03H, 1.01L, (0.99H, 0.99L) ⁶ , 1.02H from the substrate 2 side. 1.08L, 1.31H, 0.18L, 1.37H, 1.24L, 1.27H, 1.28L, (1.28H, 1.28L) ⁶ , 1.26H, 1.28L, 1.25H , 40 layers of 0.63L are formed.

Next, the grasp of warpage will be described.
In the substrate 2 on which the optical thin film 3 is formed, the formation surface 5 of the optical thin film 3 becomes concave due to the strong tensile stress of MgF ₂ of the low refractive index material layer and the weak tensile stress of TiO ₂ of the high refractive index material layer. Warpage of the warp width B occurred.
Therefore, in the pre-deformation step, based on the result of grasping the warp, the formation surface 5 of the optical thin film 3 is used as a reference surface, and the formation surface 5 of the optical thin film 3 is substantially plane-symmetric with respect to the reference surface. The substrate 2 was deformed so as to be warped.
Note that the bonding layer 18 was not used.

  Table 3 shows the measurement results of the warpage width of the substrate 2 (two pieces of No1 and No2 in each jig) in this example.

  As described above, an optical thin film including an IR cut filter function integrally formed by being bonded to the entrance surface of a CCD as a dust-proof glass of a video device such as a CCD (charge coupled device), for example, where the substrate 2 is a glass substrate. The filter 1 can be manufactured.

In addition, this invention is not limited to the above-mentioned embodiment and Example, The deformation | transformation in the range which can achieve the objective of this invention, improvement, etc. are included in this invention.
For example, the second reference point of the support portion 8 on the center side and the first support portion 10 of the outer support portion 10 shown in FIGS. The reference point 1 is the apex of the support portion 8 and the receiving plate 11 on the center side, but may be a point other than the apex.

Sectional drawing which shows the optical thin film filter which concerns on embodiment of this invention. Process drawing which shows the manufacturing method of the optical thin film filter which concerns on embodiment of this invention. Sectional drawing which shows grasp of curvature. (A) And (b) is sectional drawing which shows grasping of curvature. Sectional drawing which shows the jig | tool for a deformation | transformation used at a prior deformation process. (A) And (b) is sectional drawing which shows a prior deformation | transformation process. (A) And (b) is sectional drawing which shows a thin film formation process. The fragmentary sectional view of the front-end | tip part vicinity of the center side support part in the prior deformation | transformation process of the 1st Embodiment of this invention. The fragmentary sectional view of the front-end | tip part of the support part of the center side of the prior deformation | transformation process of the 2nd Embodiment of this invention. (A) is a top view which shows the process for providing a hole, (b) is CC sectional view taken on the line of (a). (A) And (b) is a fragmentary sectional view of the front-end | tip part vicinity of the center side support part in the prior deformation | transformation process of the 3rd Embodiment of this invention. Sectional drawing which shows a laminated optical low-pass filter. The schematic diagram which shows the optical axis of a laminated optical low-pass filter, and the advancing direction of a light ray.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical thin film filter as an optical component, 2 ... Substrate, 3 ... Optical thin film, 5 ... Formation surface (reference surface), 6 ... Deformation jig as a jig, 7 ... Jig plate, 8 ... Center side Support part, 10 ... outer support part, 15 ... center part of substrate, 16 ... outer peripheral part of substrate, 17 ... tip part of support part on the center side, 18 ... bonding layer, 19 ... joining member, 20 ... joining pair member 24 ... holes, 25 ... contact members.

Claims (5)

Based on the results of grasping the warpage that occurs when an optical thin film is formed on a substrate,
A pre-deformation step in which the substrate is deformed so that the optical thin film formation surface is a reference surface, and the formation surface is substantially warped with respect to the reference surface.
And a thin film forming step of forming the optical thin film on the substrate in a state where the deformation is applied. In the manufacturing method of the optical component according to claim 1,
Using a jig to add the deformation,
The jig includes a flat jig plate,
The jig plate is provided with an outer support portion and a center support portion,
The outer support portion is brought into contact with the outer peripheral portion of the substrate, the center-side support portion is brought into contact with the center portion of the substrate,
The method of manufacturing an optical component, wherein the deformation is applied to the substrate by adjusting a relative position between the outer support portion and the center support portion. In the manufacturing method of the optical component according to claim 2,
A bonding layer having a pressure-sensitive adhesive or an adhesive is provided at the tip of the central support portion,
The manufacturing method of an optical component, wherein the bonding layer is brought into contact with the substrate. In the manufacturing method of the optical component according to claim 2,
A joining member that joins by a magnetic force provided at the tip of the support portion on the center side;
A joining member,
A method of manufacturing an optical component, wherein the substrate is placed in opposition with the substrate interposed therebetween and brought into contact with the substrate. In the manufacturing method of the optical component according to claim 2,
A contact member is provided at the tip of the support portion on the center side,
A hole is provided in the center of the substrate,
Inserting the central support portion into the hole;
The method of manufacturing an optical component, wherein the contact member is brought into contact with the surface of the substrate.

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