JP5273025B2 - Wavelength variable interference filter, manufacturing method thereof, colorimetric sensor, and colorimetric module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tunable interference filter, a method of manufacturing the filter, a colorimetric sensor, and a colorimetric module, capable of improving the joint strength of counter substrates and preventing damaging to a mirror. <P>SOLUTION: An electrode forming groove 511, a mirror fixing part 512 and an adhesive groove 513 as a groove part are formed on a first substrate 51 by etching. The adhesive groove 513 is formed in a recess at four corners of the first substrate 51. The adhesive groove 513 is formed in a flat and substantially triangular shape. Two adjacent sides (first forming side 513A, second forming side 513B) are formed in substantially right angle along two adjacent sides of the first substrate 51, and an inner circumferential part 513C facing these two sides is formed in an arc in parallel with the outer edge of a gap forming part 55. An adhesive 53 is disposed inside the adhesive groove 513. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a wavelength tunable interference filter that selects and emits light having a desired target wavelength from incident light, a method for manufacturing the same, a colorimetric sensor including the wavelength tunable interference filter, and a colorimetric module including the colorimetric sensor. About.

2. Description of the Related Art Conventionally, there is known a variable wavelength interference filter in which high reflection mirrors are arranged to face each other on a pair of substrates. In such a tunable interference filter, only light of a specific wavelength from incident light is reflected by reflecting light between a pair of mirrors, transmitting only light of a specific wavelength, and canceling light of other wavelengths by interference. Permeate. At this time, since only the light of a desired wavelength is transmitted by changing the gap between the mirrors, the wavelength variable interference filter is required to have high gap accuracy.
In order to improve the gap accuracy, it is important to ensure uniform bonding strength in the opposing substrate surfaces.

Here, in order to form a gap between a pair of substrates, a configuration is known in which bonding is performed with an adhesive or an adhesive film interposed between bonding surfaces of both substrates (see, for example, Patent Documents 1 and 2).
The wavelength tunable interference filter described in Patent Document 1 has a use region in which two transparent substrates are opposed to each other in parallel with a predetermined gap therebetween, and a frame region along the periphery of the use region where light enters and exits at the center. And the upper surfaces of the opposed frame regions are joined together by an adhesive and integrated.
The wavelength variable interference filter described in Patent Document 2 has a configuration in which two opposing substrates are bonded via a bonding film containing a siloxane bond, and energy such as ultraviolet light and laser light is bonded to the bonding film. Adhesiveness is expressed by imparting.
In addition, a configuration is known in which a gap is maintained by interposing a spacer between opposing substrates (see, for example, Patent Documents 3, 4 and 5). Are joined by anodic bonding.

JP 2001-281443 A JP 2009-134027 A JP 2006-350124 A JP 2005-66727 A JP 2003-195031 A

  However, as in Patent Documents 1 and 2, when the opposing substrates are bonded with an adhesive or an adhesive film interposed therebetween, the bonding strength is improved, but bending occurs in the vicinity of the gap forming portion, thereby forming an accurate gap. Difficult to do. In addition, when an adhesive or an adhesive film is disposed adjacent to the space where the gap is formed, the volatile gas accompanying the curing of the adhesive is likely to enter the gap of the counter substrate and damages the mirror film. There is a fear. In particular, in Patent Document 1, ultraviolet light, laser light, or the like is used to impart adhesiveness to the adhesive film, and irradiating these may cause damage to the mirror film.

Further, as in Patent Documents 3, 4 and 5, when a spacer is used to form a gap, there are problems that the number of parts increases, the structure and process become complicated, and the cost increases.
Further, as in Patent Document 3, when the opposing substrates are bonded only by anodic bonding, the bonding strength becomes insufficient and the substrate may be peeled off.

  In view of the above-described problems, the present invention provides a wavelength tunable filter capable of improving the bonding strength of opposing substrates and preventing damage to a mirror, a manufacturing method thereof, a colorimetric sensor, and a colorimetric module. That is.

  The wavelength tunable interference filter of the present invention includes a planar polygonal first substrate, a planar polygonal second substrate disposed to face one surface of the first substrate, and the first substrate and the second substrate. A pair of mirrors which are respectively provided on surfaces facing each other and arranged to face each other with a gap; a joint surface provided on each surface facing the first substrate and the second substrate; and the first substrate. And a concave groove provided in at least one corner of the second substrate, and an adhesive member disposed in the groove.

Here, the adhesive member preferably has adhesiveness and elasticity, and for example, an adhesive having a viscosity that can maintain the shape at room temperature is used.
In this invention, the wavelength variable interference filter has a concave groove formed at one of the corners of the first substrate and the second substrate, and an adhesive member is disposed in the groove. For this reason, in the state which joined the joint surface of the 1st board | substrate and the 2nd board | substrate, both board | substrates are joined simultaneously via the adhesive member arrange | positioned at a groove part. As described above, by using the adhesive member, the first substrate and the second substrate can be more reliably bonded, and the first substrate and the second substrate can be prevented from being peeled off.
In particular, the separation between the first substrate and the second substrate is most likely to occur from the corner, but as in the present invention, a groove is formed in the corner of the substrate and the adhesive member is disposed, so a small amount of adhesive member is used. Separation of the first substrate and the second substrate can be efficiently prevented.
Further, since the groove is formed in a concave shape and the adhesive member is disposed inside the groove, the adhesive member is not sandwiched between the bonding surfaces of the first substrate and the second substrate. Therefore, since the first substrate and the second substrate bonded at the bonding surface are supported by the bonding surface, the pair of mirrors can be maintained in parallel.

  The tunable interference filter according to the aspect of the invention includes a circular gap forming portion configured to include the gap and an electrode provided along the outer peripheral edge of the gap, and the inner peripheral edge of the groove portion is formed on the inner peripheral edge. It is preferable that the gap is formed with the same curvature as the outer peripheral edge of the gap forming portion facing at the nearest position.

Here, the gap forming portion includes a gap formed between the pair of mirrors and an electrode provided along the outer periphery of the pair of mirrors. The outer peripheral edge of the gap forming portion is opposed to the inner peripheral edge of the groove provided at the corner of the substrate. The inner peripheral edge of the groove part is formed in an arc shape, and the curvature thereof is the same as the outer peripheral edge of the gap forming part that is opposed to the groove part at the closest position.
When the wavelength tunable interference filter is manufactured, when the first substrate and the second substrate are bonded with an adhesive, the substrate may be bent by a force due to curing of the adhesive. In the present invention, the inner peripheral edge of the groove portion is formed with the same curvature as the outer peripheral edge of the opposing circular gap forming portion, so that the force generated when the adhesive is hardened reaches the gap forming portion. It can diverge uniformly. Therefore, it is possible to prevent the substrate from being bent.

  In the wavelength tunable interference filter according to the aspect of the invention, it is preferable that the groove includes an escape groove that communicates the inside of the groove with the outside of the wavelength tunable interference filter.

  When the groove portion is sealed by bonding the first substrate and the second substrate, the method of applying pressure to the substrate at the time of bonding may cause the substrate to be bent by internal pressure, and the pair of mirrors may not be maintained in parallel. In addition, the substrate is bent by the force of curing of the adhesive, and the internal pressure of the groove is increased, so that the bonding by the bonding surface between the first substrate and the second substrate may be easily peeled off. In the present invention, since the escape groove that communicates the inside of the groove and the outside of the variable wavelength interference filter is provided, the internal pressure generated in the groove can be released to the outside of the variable wavelength interference filter. Therefore, bending of the first substrate and the second substrate can be prevented, and the pair of opposing mirrors can be maintained in parallel.

  In the wavelength tunable interference filter according to the aspect of the invention, it is preferable that the first substrate and the second substrate have a rectangular shape, and the groove portion and the adhesive member are provided at four corners of the rectangular shape.

  In the present invention, the variable wavelength interference filter is formed in a square shape. That is, a concave groove is formed at each of the four corners of the square first substrate and the second substrate, and an adhesive member is disposed inside each groove. Thus, since the corner | angular part of a board | substrate is joined via an adhesive member, joining strength improves and it can prevent that a board | substrate peels from a corner | angular part.

  In the wavelength tunable interference filter according to the aspect of the invention, it is preferable that the adhesive member is disposed away from the inner wall of the groove portion.

  In the present invention, the adhesive member is arranged in a separated state without adhering to the inner wall of the groove portion. If the adhesive member is attached to the inner wall of the groove part, the adhesive member may protrude from the groove part when pressed during bonding, and the gap between the pair of mirrors cannot be maintained in parallel, which may impair the optical characteristics. There is. In the present invention, since the adhesive member is disposed away from the inner wall of the groove portion, it is possible to prevent the adhesive member from protruding.

  The method for manufacturing a wavelength tunable interference filter of the present invention includes a first substrate molding step of processing a transparent substrate to mold a first substrate, a second substrate molding step of processing the transparent substrate to mold a second substrate, A groove forming step of forming a concave groove at one corner of the first substrate and the second substrate simultaneously with any one of the first substrate forming step and the second substrate forming step; An adhesive member applying step of applying an adhesive member to the groove; and a joining step of superimposing the first substrate and the second substrate and joining them with a pressure load.

  In this invention, the variable wavelength interference filter is manufactured by the first substrate forming step, the second substrate forming step, the groove forming step, the adhesive member applying step, and the joining step. Since the groove portion is formed on either the first substrate or the second substrate, the groove portion forming step is performed simultaneously with either the first substrate forming step or the second substrate forming step. And after apply | coating an adhesive member to a groove part, a 1st board | substrate and a 2nd board | substrate are piled up and it joins by a pressurization load. According to this, by applying the adhesive member, the same effects as described above can be achieved.

  In the wavelength tunable interference filter manufacturing method of the present invention, it is preferable that in the adhesive member application step, the adhesive member is applied so as to be higher than the height of the groove.

  In this invention, when apply | coating an adhesive member, it applies so that the height when apply | coating an adhesive member may become higher than the height of a groove part. Thereby, when the first substrate and the second substrate are overlaid, the adhesive member reliably adheres to both the substrates, so that the first substrate and the second substrate can be reliably bonded.

  In the wavelength tunable interference filter manufacturing method of the present invention, it is preferable that in the adhesive member application step, the adhesive member is applied at a position away from the inner wall of the groove.

  In this invention, when apply | coating an adhesive member, it applies to the position where an adhesive member does not adhere to the inner wall of a groove part. In particular, it is preferable to apply the adhesive member at a position where the adhesive member does not adhere to the inner wall of the groove even when the first substrate and the second substrate are overlapped. According to this, since there is no possibility that the adhesive member protrudes from the groove portion, it is possible to improve the bonding strength while maintaining the optical characteristics.

  A colorimetric sensor according to the present invention includes the above-described wavelength tunable interference filter and light receiving means for receiving inspection target light transmitted through the wavelength tunable interference filter.

  In the present invention, as in the above-described invention, the bonding strength between the first substrate and the second substrate can be improved while keeping the gap between the pair of mirrors of the wavelength variable interference filter constant. By receiving the emitted light emitted from such a wavelength variable interference filter by the light receiving means, the colorimetric sensor can measure the exact light quantity of the light component of the desired wavelength contained in the inspection target light.

  The color measurement module of the present invention includes the color measurement sensor described above and a color measurement processing unit that performs color measurement processing based on the light received by the light receiving unit of the color measurement sensor. And

  In the present invention, as in the above-described invention, since the bonding strength between the first substrate and the second substrate can be improved while keeping the gap between the pair of mirrors of the wavelength variable interference filter constant, the colorimetric sensor In this light receiving means, it is possible to accurately detect the light amount of the desired wavelength light included in the inspection target light. Therefore, the processing means can also accurately analyze the intensity of each color component of the inspection target light based on the exact light amount of the light having the desired wavelength included in the inspection target light.

The figure which shows schematic structure of the color measurement module of one Embodiment which concerns on this invention. The top view which shows schematic structure of the etalon which comprises the wavelength variable interference filter of the said embodiment. FIG. 3 is a cross-sectional view of the etalon taken along line III-III in FIG. 2. The top view which shows schematic structure of the 1st board | substrate of the said embodiment. It is a figure which shows the manufacturing process of the 1st board | substrate of the etalon 5 of the said embodiment, (A) is the schematic of the resist formation process which forms the resist for forming the groove | channel for electrode formation in the 1st board | substrate 51, ( B) is a schematic view of the electrode forming groove forming step, (C) is a schematic view of the adhesive groove forming step, (D) is a schematic view of the first electrode forming step, and (E) is a fixed mirror. The schematic of a formation process, (F) is the schematic of an adhesive member application | coating process. The principal part enlarged view which shows the adhesive agent provided in the groove part in FIG.5 (F). It is a figure which shows the outline of the manufacturing process of the 2nd board | substrate of the etalon 5 of the said embodiment, (A) is the schematic of the film-forming process which forms a Cr / Au film on a board | substrate, (B) is the 2nd The schematic of an electrode formation process, (C) is the schematic of a diaphragm formation process, (D) is the schematic which shows a mirror formation process.

Hereinafter, a color measurement module according to an embodiment of the present invention will be described with reference to the drawings.
[1. Overall configuration of the color measurement module)
FIG. 1 is a diagram showing a schematic configuration of a color measurement module according to the first embodiment of the present invention.
As shown in FIG. 1, the color measurement module 1 includes a light source device 2 that emits light to an inspection target A, a color measurement sensor 3 according to the present invention, and a control device 4 that controls the overall operation of the color measurement module 1. And. The color measurement module 1 reflects the light emitted from the light source device 2 by the inspection target A, receives the reflected inspection target light by the color measurement sensor, and outputs the light from the color measurement sensor 3. This module analyzes and measures the chromaticity of the inspection target light, that is, the color of the inspection target A based on the detection signal.

[2. Configuration of light source device]
The light source device 2 includes a light source 21 and a plurality of lenses 22 (only one is shown in FIG. 1), and emits white light to the inspection target A. The plurality of lenses 22 include a collimator lens, and the light source device 2 converts the white light emitted from the light source 21 into parallel light by the collimator lens, and passes from the projection lens (not shown) to the object A to be inspected. Ejected towards.

[3. (Configuration of colorimetric sensor)
As shown in FIG. 1, the colorimetric sensor 3 transmits the etalon 5 constituting the wavelength tunable interference filter of the present invention, a light receiving element 31 as a light receiving means for receiving light transmitted through the etalon 5, and the etalon 5. Voltage control means 6 for changing the wavelength of light. Further, the colorimetric sensor 3 includes an incident optical lens (not shown) that guides reflected light (inspection target light) reflected by the inspection target A at a position facing the etalon 5. The colorimetric sensor 3 uses the etalon 5 to split only the light having a predetermined wavelength out of the inspection target light incident from the incident optical lens, and the light receiving element 31 receives the split light.
The light receiving element 31 includes a plurality of photoelectric exchange elements, and generates an electrical signal corresponding to the amount of received light. The light receiving element 31 is connected to the control device 4 and outputs the generated electrical signal to the control device 4 as a light reception signal.

(3-1. Composition of etalon)
FIG. 2 is a plan view showing a schematic configuration of the etalon 5 constituting the tunable interference filter of the present invention, and FIG. 3 is a cross-sectional view showing a schematic configuration of the etalon 5. In FIG. 1, the inspection target light is incident on the etalon 5 from the lower side in the figure, but in FIG. 3, the inspection target light is incident from the upper side in the figure.
As shown in FIG. 2, the etalon 5 is a planar square plate-shaped optical member, and one side is formed, for example, at 20 mm. The etalon 5 includes a first substrate 51 and a second substrate 52 as shown in FIG. These two substrates 51 and 52 are each formed of, for example, various glasses such as soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and alkali-free glass, or crystal. . Among these, as a constituent material of each board | substrate 51,52, the glass containing alkali metals, such as sodium (Na) and potassium (K), for example is preferable, and each board | substrate 51,52 is formed with such glass. Thus, it becomes possible to improve the adhesion between the mirrors 56 and 57, which will be described later, and the electrodes, and the bonding strength between the substrates. These two substrates 51 and 52 have bonding surfaces 51A and 52A formed in the vicinity of the outer peripheral portion in pressure bonding such as room temperature activation bonding and adhesive grooves 513 formed in corners, for example. By being joined by an adhesive 53 as an arranged adhesive member, it is configured integrally.

Further, between the first substrate 51 and the second substrate 52, a fixed mirror 56 and a movable mirror 57 constituting a pair of mirrors of the present invention are provided. Here, the fixed mirror 56 is fixed to the surface of the first substrate 51 facing the second substrate 52, and the movable mirror 57 is fixed to the surface of the second substrate 52 facing the first substrate 51. Further, the fixed mirror 56 and the movable mirror 57 are disposed to face each other with a gap G between the mirrors.
Furthermore, an electrostatic actuator 54 for adjusting the dimension of the inter-mirror gap G between the fixed mirror 56 and the movable mirror 57 is provided between the first substrate 51 and the second substrate 52.
Here, a circular region including the inter-mirror gap G formed by the fixed mirror 56 and the movable mirror 57 and the electrostatic actuator 54 is defined as a gap forming portion 55.

(3-1-1. Configuration of the first substrate)
The first substrate 51 is formed by processing a glass substrate having a thickness of, for example, 500 μm by etching. Specifically, as shown in FIG. 3, an electrode forming groove 511, a mirror fixing portion 512, and an adhesive groove 513 as a groove portion are formed on the first substrate 51 by etching.
The electrode forming groove 511 is formed in a circular shape centered on the plane center point in a plan view (hereinafter referred to as etalon plan view) of the etalon 5 as shown in FIG. The mirror fixing portion 512 is formed so as to protrude from the center portion of the electrode forming groove 511 toward the second substrate 52 in the plan view.

The electrode forming groove 511 has a ring-shaped electrode fixing surface 511A formed between the outer peripheral edge of the mirror fixing portion 512 and the inner peripheral wall surface of the electrode forming groove 511, and the electrode fixing surface 511A has a first A displacement electrode 541 is formed. Further, from a part of the outer peripheral edge of the first displacement electrode 541, the first displacement electrode lead-out portion 541A is directed to the left direction and the right direction of the etalon 5 in the plan view of the etalon as shown in FIG. It is formed to extend. Further, first displacement electrode pads 541B are respectively formed at the tips of the first displacement electrode lead portions 541A, and these first displacement electrode pads 541B are connected to the voltage control means 6.
Here, when the electrostatic actuator 54 is driven, a voltage is applied to only one of the pair of first displacement electrode pads 541B by the voltage control means 6. The other first displacement electrode pad 541B is used as a detection terminal for detecting the charge retention amount of the first displacement electrode 541.

  As described above, the mirror fixing portion 512 is formed in a columnar shape that is coaxial with the electrode forming groove 511 and has a smaller diameter than the electrode forming groove 511. In the present embodiment, as shown in FIG. 3, the mirror fixing surface 512A facing the second substrate 52 of the mirror fixing portion 512 is formed closer to the second substrate 52 than the electrode fixing surface 511A. However, the present invention is not limited to this. The height positions of the electrode fixing surface 511A and the mirror fixing surface 512A are the dimensions of the inter-mirror gap G between the fixed mirror 56 fixed to the mirror fixing surface 512A and the movable mirror 57 formed on the second substrate 52. It is appropriately set according to the dimension between the first displacement electrode 541 and the second displacement electrode 542 described later formed on the second substrate 52 and the thickness dimension of the fixed mirror 56 and the movable mirror 57. It is not limited to the configuration. For example, when dielectric multilayer mirrors are used as the mirrors 56 and 57 and the thickness dimension thereof increases, a configuration in which the electrode fixing surface 511A and the mirror fixing surface 512A are formed on the same surface, or the central portion of the electrode fixing surface 511A Alternatively, a mirror fixing groove on the cylindrical concave groove may be formed, and a mirror fixing surface 512A may be formed on the bottom surface of the mirror fixing groove.

  In addition, the mirror fixing surface 512A of the mirror fixing portion 512 is preferably designed with a groove depth in consideration of the wavelength range through which the etalon 5 is transmitted. For example, in this embodiment, the initial value of the inter-mirror gap G between the fixed mirror 56 and the movable mirror 57 (between the mirrors in a state where no voltage is applied between the first displacement electrode 541 and the second displacement electrode 542). The dimension of the gap G) is set to 450 nm, and by applying a voltage between the first displacement electrode 541 and the second displacement electrode 542, the movable mirror 57 is displaced until the inter-mirror gap G becomes, for example, 250 nm. As a result, by changing the voltage between the first displacement electrode 541 and the second displacement electrode 542, light having a wavelength in the entire visible light range can be selectively dispersed and transmitted. It becomes possible. In this case, if the film thickness of the fixed mirror 56 and the movable mirror 57 and the height dimension of the mirror fixing surface 512A and the electrode fixing surface 511A are set to values that allow the gap G between the mirrors to be displaced between 250 nm and 450 nm. Good.

A fixed mirror 56 formed in a circular shape having a diameter of about 3 mm is fixed to the mirror fixing surface 512A. The fixed mirror 56 is a mirror formed of an AgC single layer, and is formed on the mirror fixed surface 512A by a technique such as sputtering.
In the present embodiment, an example in which an AgC single layer mirror that can cover the entire visible light region as a wavelength region that can be dispersed by the etalon 5 is used as the fixed mirror 56 is not limited to this. Although the spectral wavelength range is narrow, the transmittance of the dispersed light is larger than that of the AgC single layer mirror, the half width of the transmittance is narrow, and the resolution is good. For example, a TiO ₂ —SiO ₂ dielectric multilayer mirror It is good also as a structure using. However, in this case, as described above, the height positions of the mirror fixing surface 512A and the electrode fixing surface 511A of the first substrate 51 are appropriately set by the fixed mirror 56, the movable mirror 57, the wavelength selection range of the light to be dispersed, and the like. There is a need to.

The adhesive grooves 513 are formed in concave shapes at the four corners of the first substrate 51 in a plan view of the first substrate 51 shown in FIG. The adhesive groove 513 is formed in a substantially triangular shape on the plane, and two adjacent sides (first forming side 513A and second forming side 513B) are formed at substantially right angles along the two adjacent sides of the first substrate 51. In addition, the inner peripheral edge portion 513C facing these two sides is formed in an arc shape having the same curvature as the outer peripheral edge of the gap forming portion 55 facing the inner peripheral edge portion 513C at the closest position. The adhesive groove 513 includes a fourth forming side 513D that connects the inner peripheral edge 513C and the first forming side 513A, and a fifth forming side 513E that connects the inner peripheral edge 513C and the second forming side 513B. ,have.
The groove 513 for adhesive has a groove bottom surface 513F located in the same plane of the mirror fixing surface 512A. With such a configuration, in the manufacturing process, the mirror fixing portion 512 and the adhesive groove 513 can be simultaneously formed by etching.

An adhesive 53 is disposed inside the adhesive groove 513. The volume of the adhesive groove 513 is larger than the volume of the applied adhesive 53, and the adhesive 53 is disposed in a state of being separated from the inner wall of the adhesive groove 513. As a specific example of such a state, for example, a volume of 1.1 in which the length of the first forming side 513A and the second forming side 513B of the adhesive groove 513 is 3 mm and the depth of the adhesive groove 513 is 120 nm. An adhesive 53 having a volume of 0.63 × 10 ⁻¹³ m ³ is disposed in the adhesive groove 513 having a size of 25 × 10 ⁻¹³ m ³ . As described above, since the volume of the adhesive 53 is sufficiently small with respect to the volume of the adhesive groove 513, the adhesive 53 can be disposed at a position away from the inner wall of the adhesive groove 513.
The adhesive groove 513 includes a relief groove 514 that communicates from the first formation side 513A to the outside of the etalon 5 and a relief groove 515 that communicates from the second formation side 513B to the outside of the etalon 5. The escape grooves 514 and 515 have the same depth as the adhesive groove 513, and when the first substrate 51 and the second substrate 52 are overlapped, the inside of the adhesive groove 513 and the outside of the etalon 5. And the internal pressure in the adhesive groove 513 is released to the outside of the etalon 5.

  Furthermore, the first substrate 51 is provided with an antireflection film (AR) (not shown) at a position corresponding to the fixed mirror 56 on the lower surface opposite to the upper surface facing the second substrate 52. This antireflection film is formed by alternately laminating low refractive index films and high refractive index films, and reduces the reflectance of visible light on the surface of the first substrate 51 and increases the transmittance.

(3-1-2. Configuration of Second Substrate)
The second substrate 52 is formed by processing a glass substrate having a thickness of, for example, 200 μm by etching.
Specifically, the second substrate 52 has a circular movable portion 521 centered on the substrate center point and a connection that is coaxial with the movable portion 521 and holds the movable portion 521 in a plan view as shown in FIG. Holding part 522.

The movable portion 521 is formed to have a thickness dimension larger than that of the connection holding portion 522. For example, in the present embodiment, the movable portion 521 is formed to be 200 μm, which is the same dimension as the thickness dimension of the second substrate 52. The movable portion 521 includes a movable surface 521A parallel to the mirror fixing portion 512, and the movable mirror 57 is fixed to the movable surface 521A. Here, the movable mirror 57 and the fixed mirror 56 described above constitute a pair of mirrors of the present invention. In the present embodiment, the inter-mirror gap G between the movable mirror 57 and the fixed mirror 56 is set to 450 nm in the initial state.
Here, the movable mirror 57 is a mirror having the same configuration as the fixed mirror 56 described above, and in this embodiment, an AgC single layer mirror is used. The film thickness dimension of the AgC single layer mirror is, for example, 0.03 μm.

The etalon 5 applies a predetermined voltage to the electrostatic actuator 54, thereby moving the movable portion 521 along the substrate thickness direction to adjust the gap G between the mirrors, and to select light to be split from the inspection target light. Is possible.
The movable portion 521 has an antireflection film (AR) (not shown) formed at a position corresponding to the movable mirror 57 on the upper surface opposite to the movable surface 521A. This antireflection film has the same configuration as the antireflection film formed on the first substrate 51, and is formed by alternately laminating a low refractive index film and a high refractive index film.

The connection holding part 522 is a diaphragm surrounding the periphery of the movable part 521, and has a thickness dimension of, for example, 50 μm. A ring-shaped second displacement electrode 542 facing the first displacement electrode 541 with an electromagnetic gap of about 1 μm is formed on the surface of the connection holding portion 522 facing the first substrate 51. . Here, the second displacement electrode 542 and the first displacement electrode 541 described above constitute an electrostatic actuator 54 which is a variable means of the present invention.
Also, a pair of second displacement electrode lead portions 542A are formed from the part of the outer peripheral edge of the second displacement electrode 542 toward the outer peripheral direction, and at the tip of these second displacement electrode lead portions 542A A second displacement electrode pad 542B is formed. More specifically, the second displacement electrode lead-out portion 542A and the second displacement electrode pad 542B are disposed upward and downward from the gap forming portion 55 of the first substrate 51 as shown in FIG. It is formed point-symmetrically with respect to the plane center at a position extending toward the center.
Similarly to the first displacement electrode pad 541B, the second displacement electrode pad 542B is connected to the voltage control means 6, and when the electrostatic actuator 54 is driven, of the pair of second displacement electrode pads 542B. A voltage is applied to only one of them. The other second displacement electrode pad 542B is used as a detection terminal for detecting the charge retention amount of the second displacement electrode 542.

(3-2. Configuration of voltage control means)
The voltage control means 6 constitutes the variable wavelength interference filter of the present invention together with the etalon 5. The voltage control means 6 controls the voltage applied to the first displacement electrode 541 and the second displacement electrode 542 of the electrostatic actuator 54 based on a control signal input from the control device 4.

[4. Configuration of control device]
The control device 4 controls the overall operation of the color measurement module 1.
As this control device 4, for example, a general-purpose personal computer, a portable information terminal, or a color measurement computer can be used.
As shown in FIG. 1, the control device 4 includes a light source control unit 41, a colorimetric sensor control unit 42, a colorimetric processing unit 43, and the like.
The light source control unit 41 is connected to the light source device 2. Then, the light source control unit 41 outputs a predetermined control signal to the light source device 2 based on, for example, a user setting input, and causes the light source device 2 to emit white light with a predetermined brightness.
The colorimetric sensor control unit 42 is connected to the colorimetric sensor 3. The colorimetric sensor control unit 42 sets a wavelength of light received by the colorimetric sensor 3 based on, for example, a user's setting input, and outputs a control signal for detecting the amount of light received at this wavelength. Output to the colorimetric sensor 3. Thereby, the voltage control means 6 of the colorimetric sensor 3 sets the voltage applied to the electrostatic actuator 54 so as to transmit only the wavelength of light desired by the user based on the control signal.

[5. Etalon Manufacturing Method)
The etalon 5 is manufactured by a first substrate forming process, a second substrate forming process, a groove forming process, an adhesive applying process, and a joining process. Hereinafter, description will be given based on the drawings.
(5-1. First substrate forming step and groove forming step)
In the present embodiment, since the adhesive groove 513 is formed on the first substrate 51, the groove forming step is performed simultaneously with the first substrate forming step.

In order to manufacture the first substrate 51, first, as shown in FIG. 5A, a quartz glass substrate 50 (surface roughness Ra = 1 nm or less, thickness 500 μm) which is a manufacturing material of the first substrate 51 is desired. Then, a resist 61 having the above pattern is formed (resist forming step), and as shown in FIG. 5B, an electrode forming groove 511 having a depth of 1 μm is formed (electrode forming groove forming step).
Specifically, in the resist formation step, a resist 61 is formed on one surface 50A of the quartz glass substrate 50 that becomes the bonding surface 51A when the first substrate 51 is formed. In the electrode forming groove forming step, the portion where the resist 61 is not formed is anisotropically etched to form the electrode forming groove 511.

In addition, after the formation of the electrode forming groove 511, a resist 61 having a pattern of the mirror fixing portion 512 and the adhesive groove 513 on the bonding surface 51A is formed, and anisotropic etching is performed (adhesive groove forming step). ). Thus, an adhesive groove 513 and a mirror fixing portion 512 having a depth of 120 nm are formed (see FIG. 5C). Here, the mirror fixing surface 512A and the groove bottom surface 513F of the adhesive groove 513 are located in the same plane.
Note that the area of the adhesive groove 513 in plan view is preferably as small as possible within a range in which the adhesive strength can be maintained.

Thereafter, the resist 61 on the quartz glass substrate 50 is removed, and a Cr / Au film for forming electrodes is formed on the entire surface of the quartz glass substrate 50 by sputtering (not shown). The thickness of each film at this time is a Cr film of 10 nm and an Au film of 200 nm. Then, a resist serving as a desired electrode pattern is formed and etched to form a first displacement electrode 541 shown in FIG. 5D (first electrode formation step).
Next, an AgC film is formed on the entire surface of the quartz glass substrate 50 by sputtering (not shown). The thickness of the film may be appropriately adjusted according to the desired optical characteristics, but in this embodiment, the thickness is formed to be 30 nm (fixed mirror forming step). In the fixed mirror forming step, a resist is formed on each of the formed portions of the fixed mirror 56 on the formed AgC film. And the fixed mirror 56 is formed as shown in FIG.5 (E) by removing the AgC thin film of the part in which the resist is not provided.

Next, the adhesive 53 is applied to the adhesive groove 513 of the quartz glass substrate 50 (adhesive application step). The application method is not particularly limited, and for example, methods such as film transfer, squeegee, and dispensing can be used.
The adhesive 53 is applied at a position where it does not contact the inner wall of the adhesive groove 513. In particular, even when the first substrate 51 and the second substrate 52 are overlapped and the adhesive 53 is deformed, the adhesive 53 is not applied. It is applied to a position that does not contact the inner wall of the adhesive groove 513. Also, the amount of the adhesive 53 applied is preferably smaller than the volume of the adhesive groove 513 and is an appropriate amount that does not contact the inner wall of the adhesive groove 513. Specific coating amounts are shown in FIG. In FIG. 6, the adhesive 53 is applied at a position of 0.25 mm from the second forming side 513B (inner wall) of the adhesive groove 513. The adhesive 53 is applied in a shape of 0.5 mm long × 0.5 mm wide × 250 nm high. Here, the depth of the adhesive groove 513 is 120 nm. Even when the first substrate 51 and the second substrate 52 are overlapped with each other and the adhesive 53 is deformed, the adhesive 53 applied in such dimensions and amount is adhered to the inner wall of the adhesive groove 513. It will not adhere.
Thus, the first substrate 51 is formed.

(5-2. Second substrate forming step)
Next, a method for manufacturing the second substrate 52 will be described.
In order to manufacture the second substrate 52, first, as shown in FIG. 7A, both surfaces of a quartz glass substrate 50 (surface roughness Ra = 1 nm or less, thickness 200 μm) which is a manufacturing material of the second substrate 52 are used. Then, Cr / Au films 62 and 63 are formed by sputtering. The thickness of each film at this time is a Cr film of 10 nm and an Au film of 200 nm (film formation process).
Then, on the surface 50A on the side where the diaphragm is formed, the Cr / Au film 62 is used as an etching mask, so that the portion of the Cr / Au film corresponding to the connection holding portion 522 (diaphragm) is removed (FIG. 7B). reference).
On the other hand, on the surface 50B on the electrode forming side, the second displacement electrode 542 is formed by performing photolithography and etching along the desired electrode pattern on the Cr / Au film 62 (FIG. 7B). ) Reference, second electrode formation step).

Next, etching is performed on the surface 50A on the diaphragm forming side to form a connection holding portion 522 (diaphragm) (diaphragm forming step), and the Cr / Au film 62 on the surface 50A on the diaphragm forming side is removed ( (See FIG. 7C).
Thereafter, an AgC film is formed on the entire surface 50B of the quartz glass substrate 50 on which the electrodes are to be formed by sputtering. The thickness of the film may be adjusted as appropriate according to desired optical characteristics, but in this embodiment, the thickness is formed to be 30 nm. In the AgC formation step, a resist is formed on each of the formed portions of the movable mirror 57 on the formed AgC film. And the movable mirror 57 is formed as shown in FIG.7 (D) by removing the AgC thin film of the part in which the resist is not provided (mirror formation process).

(5-3. Production of etalon)
Next, the manufacture of the etalon 5 using the first substrate 51 and the second substrate 52 manufactured as described above will be described.
First, a bonding process for bonding the first substrate 51 and the second substrate 52 is performed.
In this bonding step, for example, room temperature activated bonding (optical contact) is used. That is, in the bonding process, the substrates 51 and 52A are activated by putting each of the substrates 51 and 52 in a vacuum chamber and performing irradiation with an ion beam or plasma treatment in a vacuum state. Then, the activated bonding surfaces 51A and 52A are overlapped with each other, and an equal weight (for example, 100 kgf) is applied to the thickness direction of the first substrate 51 and the second substrate 52, whereby the first substrate 51 And the 2nd board | substrate 52 is joined.
In addition, when applying a load, in order to prevent bending of the gap forming part 55 due to a pressurized load, a spacer material (for example, on the second substrate 52 is applied so that a load is applied to a part other than the gap forming part 55. It is preferable to carry out in a state where a Teflon sheet) is sandwiched.

[6. (Effects of Embodiment)
As described above, in the etalon 5 of the above embodiment, the adhesive grooves 513 are formed at the four corners in the plan view of the first substrate 51 and the second substrate 52, respectively, and the adhesive 53 is formed inside the adhesive groove 513. Is arranged.
For this reason, when the 1st board | substrate 51 and the 2nd board | substrate 52 are piled up, since the 1st board | substrate 51 and the 2nd board | substrate 52 join via the adhesive agent 53, adhesive strength improves. In particular, since the adhesive grooves 513 are formed at the four corners of the substrate, peeling from the corners of the substrate can be efficiently prevented.

  The adhesive groove 513 is formed in a concave shape on the bonding surface 51A of the first substrate 51, and the adhesive 53 is disposed inside the groove. For this reason, when the 1st board | substrate 51 and the 2nd board | substrate 52 are piled up, an adhesive agent does not intervene between the joint surface 51A and the joint surface 52A. That is, the first substrate 51 and the second substrate 52 are bonded by room temperature activation bonding (optical contact) and are supported by the bonding surfaces 51A and 52A. The gap between the mirrors 57) can be kept constant.

  Furthermore, in the etalon 5 of the above embodiment, the adhesive grooves 513 are formed at the four corners of the substrate. That is, since the adhesive 53 is applied to the adhesive groove 513, which is a completely different space away from the gap forming portion 55 where the pair of mirrors are disposed, the volatile gas accompanying the curing of the adhesive 53 is caused to flow into the gap forming portion. 55 does not enter. Therefore, it is possible to prevent damage to the fixed mirror 56 and the movable mirror 57, which has been a problem in the past.

The inner peripheral edge 513 </ b> C on the inner peripheral side of the adhesive groove 513 is formed in an arc shape parallel to the outer edge of the gap forming portion 55.
When the first substrate 51 and the second substrate 52 are overlapped and bonded by pressure, bending occurs in the radial direction near the gap forming portion 55. In the present embodiment, since the adhesive groove 513 is formed in parallel to the outer edge of the gap forming portion 55, when the deflection is transmitted to the adhesive groove 513, the adhesive is released all at once. That is, since the force can be released at the same time, the influence of the deflection can be minimized. Thus, by preventing bending as much as possible, the gap between the pair of mirrors can be maintained in parallel, and the accuracy can be improved.

  In the above embodiment, the escape grooves 514 and 515 that communicate the inside and the outside of the adhesive groove 513 are provided. When the first substrate 51 and the second substrate 52 are overlapped and joined by pressure, an internal pressure is generated in the adhesive groove 513, but the internal air can be released to the outside by the escape grooves 514 and 515. . Accordingly, since no excessive internal pressure is applied to the adhesive groove 513, it is possible to prevent the substrate from being bent.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above embodiment, the adhesive groove 513 having a substantially triangular shape in plan view is formed at the corner of the first substrate 51, but the shape of the adhesive groove 513 is not limited thereto. Any shape may be used as long as the adhesive 53 does not contact the inner wall. In the above embodiment, the inner peripheral edge portion 513C on the inner peripheral side of the adhesive groove 513 is formed in an arc shape parallel to the outer edge of the gap forming portion 55. However, the present invention is not limited to this. For example, the adhesive groove 513 may be formed in a circular shape in plan view or a polygonal shape in plan view.

Moreover, in the said embodiment, although the etalon 5 was formed in square shape, if it is planar polygonal shape, it will not be restricted to this. In the etalon formed in a planar polygonal shape, an adhesive groove is formed at one of the corners of the first substrate and the second substrate, and the adhesive is disposed in the adhesive groove. For this reason, peeling from the corner | angular part of a board | substrate can be prevented.
Furthermore, in the above embodiment, the adhesive groove 513 is formed in the first substrate 51, but the adhesive groove may be formed in the corner of the second substrate 52. According to this, the same effect as the case where the groove | channel 513 for adhesives of the above-mentioned 1st board | substrate 51 is formed can be show | played.

  DESCRIPTION OF SYMBOLS 1 ... Color measuring module, 3 ... Color measuring sensor, 4 ... Control apparatus, 5 ... Etalon which comprises a wavelength variable interference filter, 6 ... Voltage control means which comprises a wavelength variable interference filter, 31 ... Light receiving element which is a light receiving means, DESCRIPTION OF SYMBOLS 43 ... Colorimetric process part, 51 ... 1st board | substrate, 513 ... Groove for adhesive agents which are groove parts, 52 ... 2nd board | substrate, 53 ... Adhesive agent which is an adhesive member, 54 ... Electrostatic actuator, 56 ... Fixed mirror, 57 ... movable mirror.

Claims (10)

A planar polygonal first substrate;
A planar polygonal second substrate disposed to face one surface of the first substrate;
A pair of mirrors provided on the mutually opposing surfaces of the first substrate and the second substrate, respectively, and arranged to face each other across a gap;
A pair of displacement electrodes provided on opposite surfaces of the first substrate and the second substrate, respectively, and capable of varying the size of the gap;
A bonding surface provided on each of the first substrate and the second substrate facing each other;
A concave groove provided in at least one corner of the first substrate and the second substrate;
An adhesive member disposed in the groove;
A wavelength tunable interference filter comprising: The tunable interference filter according to claim 1,
A circular gap forming portion configured to include the gap and an electrode provided along an outer peripheral edge of the gap;
The wavelength tunable interference filter, wherein the inner peripheral edge of the groove is formed with the same curvature as the outer peripheral edge of the gap forming portion facing at a position closest to the inner peripheral edge. In the wavelength tunable interference filter according to claim 1 or 2,
The wavelength tunable interference filter, wherein the groove includes an escape groove that communicates the inside of the groove with the outside of the wavelength tunable interference filter. In the wavelength variable interference filter according to any one of claims 1 to 3,
The first substrate and the second substrate are rectangular.
The wavelength variable interference filter, wherein the groove and the adhesive member are provided at four corners of the square shape. In the wavelength variable interference filter according to any one of claims 1 to 4,
The wavelength variable interference filter, wherein the adhesive member is disposed away from the inner wall of the groove. Forming a first substrate by forming a first mirror and a first displacement electrode on a transparent substrate;
A second substrate forming step of forming the second substrate by forming the second mirror and the second displacement electrode on the transparent substrate;
A groove forming step of forming a concave groove at one corner of the first substrate and the second substrate simultaneously with any one of the first substrate forming step and the second substrate forming step;
An adhesive member application step of applying an adhesive member to the groove,
A joining step of superimposing the first substrate and the second substrate and joining them by a pressure load;
A tunable interference filter manufacturing method comprising: In the manufacturing method of the wavelength variable interference filter according to claim 6,
In the adhesive member application step, the adhesive member is applied in a state of being higher than the height of the groove portion. In the manufacturing method of the wavelength tunable interference filter according to claim 6 or 7,
In the adhesive member application step, the adhesive member is applied at a position away from the inner wall of the groove. The wavelength variable interference filter according to any one of claims 1 to 5,
A light receiving means for receiving the inspection object light transmitted through the wavelength variable interference filter;
A colorimetric sensor comprising: A colorimetric sensor according to claim 9;
A colorimetric processing unit that performs colorimetric processing based on the light received by the light receiving means of the colorimetric sensor;
A colorimetry module comprising:

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