JP6907884B2 - Interference filters, optical filter devices, optical modules, and electronics - Google Patents

Description

The present invention relates to interference filters, optical filter devices, optical modules, and electronic devices.

Conventionally, there is known an interference filter in which a pair of mirrors are arranged so as to face each other, and incident light is multiplely interfered with each other to emit light having a target wavelength. In such an interference filter, in order to output light of a target wavelength with high resolution, it is preferable to use a mirror having high reflection characteristics with respect to the target wavelength range. As such a mirror, an interference filter using a dielectric multilayer film in which high refraction layers and low refraction layers are alternately laminated is conventionally known (see, for example, Patent Document 1).

The interference filter described in Patent Document 1 has a fixed substrate and a movable substrate arranged to face each other, and a fixed reflective film (mirror) formed of a dielectric multilayer film is formed on the entire surface of the fixed substrate facing the movable substrate. A movable reflective film (mirror) formed of a dielectric multilayer film is formed on the entire surface of the movable substrate facing the fixed substrate. In such an interference filter, a dielectric multilayer film is used as compared with a case where a dielectric multilayer film is formed on a part of the surface of the fixed substrate facing the movable substrate or a part of the surface of the movable substrate facing the fixed substrate. (For example, a lift-off step, etc.) is not required, and the manufacturing efficiency is improved.
Further, in the case where the dielectric multilayer film is formed in a part of the substrate by a lift-off step or the like and then the electrode is formed from the dielectric multilayer film to the substrate, the electrode is formed on the end surface (side surface) of the dielectric multilayer film. Is placed. In such a case, it is difficult to form an electrode on the end face of the dielectric multilayer film, and a part of the electrode may be broken. On the other hand, in an interference filter as in Patent Document 1, since the electrode may be formed on the surface of the dielectric multilayer film, inconveniences such as disconnection of the electrode can be suppressed.

Japanese Unexamined Patent Publication No. 2015-688860

By the way, in the interference filter described in Patent Document 1, drive electrodes are arranged on each of the fixed substrate and the movable substrate to function as an electrostatic actuator. Here, when the dielectric multilayer film has a film layer having conductivity in part, there is a problem that the film layer having conductivity also becomes charged.
For example, when the conductive film layer is charged, the portion other than the drive electrode that is desired to function as the electrostatic actuator is also charged, so that the area of the electrostatic actuator is apparently expanded. The gap size between the mirrors gradually narrows. In this case, the voltage control for accurately setting the gap dimension between the mirrors to a predetermined dimension becomes complicated.

An object of the present invention is to provide an interference filter, an optical filter device, an optical module, and an electronic device capable of reducing the influence of charging of a dielectric multilayer film.

The interference filter of one application example according to the present invention includes a first substrate, a first reflective film provided over one surface of the first substrate, and at least a plan view of the first substrate when viewed from the thickness direction. A second reflective film that overlaps the first reflective film in a predetermined mirror region and is arranged with respect to the first reflective film through a gap, and a first wiring electrode provided on the first reflective film. The first reflective film is a laminated body in which insulating layers and conductive layers are alternately laminated, and a part of the first reflective film is provided in the stacking direction of the insulating layer and the conductive layer. A first through hole is provided in which at least one of the conductive layers is exposed, and the first wiring electrode is connected to the first through hole and conducts to the conductive layer exposed from the first through hole. It is characterized by that.

In this application example, the first reflection is a laminate (dielectric multilayer film) in which conductive layers and insulating layers are alternately laminated over one surface of the first substrate, that is, substantially the entire surface of one surface of the first substrate. A membrane is provided. With such a configuration, a lift-off step or the like is unnecessary, and the manufacturing efficiency of the interference filter is improved.
On the other hand, in such a configuration in which the first reflective film is provided on substantially the entire surface of one surface of the first substrate, for example, when a driving electrode or the like is provided and a voltage is applied, the conductive layer is charged. On the other hand, in this application example, the first reflective film is provided with a first through hole in which the conductive layer is exposed, and the conductive layer exposed from the first through hole is connected to the first wiring electrode. There is. Therefore, even when the conductive layer is charged, the charge can be released from the first wiring electrode, and the influence of the charge can be suppressed.

In the interference filter of this application example, the first through hole is provided in the first through hole provided in the insulating layer and the conductive layer in contact with the first substrate side of the insulating layer and is provided in the first through hole. It is preferable that the second through hole is located inside the first through hole in the plan view, including the second through hole communicating with the hole.

In this application example, the first through hole forming the first through hole is provided in one of the plurality of insulating layers constituting the first reflective film. Further, a second through hole forming the first through hole is provided in the conductive layer adjacent to the first substrate side of the insulating layer. Then, in a plan view, the second through hole is arranged inside the first through hole.
That is, the first through hole has a stepped shape between the insulating layer provided with the first through hole and the conductive layer provided with the second through hole, and a part of the upper surface of the conductive layer is inside the first through hole. Exposed to. In such a configuration, for example, as compared with a configuration in which only the side surface of the first conductive layer is exposed in the first through hole, it is easier to connect the first wiring electrode to the first conductive layer, and the charge of the first conductive layer is charged. Can be properly escaped.

The interference filter of this application example includes a second substrate facing the first substrate, the second reflective film is provided over the surface of the second substrate facing the first substrate, and an insulating layer. A first layer in which the conductive layer and the conductive layer are laminated, and a part of the second reflective film is provided along the stacking direction of the insulating layer and the conductive layer, and at least one of the conductive layers is exposed. The second through hole is provided, and the second through hole is provided with a second wiring electrode connected to the second through hole and conducting to the conductive layer exposed from the second through hole. preferable.

In this application example, in the second substrate facing the first substrate, a second reflective film which is a laminate of an insulating layer and a conductive layer is provided as in the case of the first reflective film, and the second reflective film is conductive. A second through hole is provided in which a part of the layer is exposed. A second wiring electrode that is connected to the second through hole and conducts to a part of the conductive layer of the second reflective film is provided on the second reflective film.
Therefore, as in the above application example, even when the conductive layer of the second reflective film is charged, the charge can be released from the second wiring electrode, and the influence of the charge can be suppressed.

The interference filter of the present application example includes a protruding portion that projects from the first substrate toward the second substrate and is inserted into the second through hole at a position overlapping the second through hole in the plan view. The first wiring electrode is provided from above the first reflective film to the protruding tip surface of the protruding portion, and a part of the second wiring electrode faces the first substrate of the second through hole. It is preferable that the first wiring electrode is extended to the second bottom surface and is provided on the protruding tip surface.

By the way, in the case where the first substrate and the second substrate are arranged to face each other with a predetermined distance, when the first wiring electrode and the second wiring electrode are connected, at least one of the first substrate and the second substrate is connected to the other. An facing protrusion may be provided, and an electrode may be formed on the protrusion to connect to the other electrode (so-called bump connection). However, when a part of the first wiring electrode provided at the tip of the protruding portion is connected to the second wiring electrode provided on the second reflective film, at least the thickness dimension of the second reflective film which is a laminated body The first substrate and the second substrate are separated by the total of the protruding dimensions of the protruding portion, and the size of the interference filter is increased by that amount.
On the other hand, in this application example, the protruding portion protruding from the first substrate is inserted into the second through hole, and the second wiring electrode and the first wiring electrode come into contact with each other on the bottom surface of the second through hole. Therefore, the first substrate and the second substrate can be brought close to each other, and the size of the interference filter can be reduced. In particular, if the second through hole penetrating the second reflective film is provided, the bottom surface of the second through hole becomes the same surface as the substrate surface of the second substrate, and the interference filter can be further miniaturized. ..

In the interference filter of this application example, it is preferable that the protruding portion protrudes from the first bottom surface of the first through hole facing the second substrate toward the second substrate.

In this application example, the above-mentioned protruding portion protrudes from the bottom surface of the first through hole toward the second substrate. When a protruding portion is formed so as to project from the first reflective film, which is a laminated body, toward the second substrate, the distance between the first substrate and the second substrate is increased by the thickness dimension of the first reflective film. On the other hand, the distance between the first substrate and the second substrate can be shortened by making the protruding portion protrude from the bottom surface of the first through hole. In particular, if the first through hole penetrating the first reflective film is provided, the bottom surface of the first through hole becomes the same surface as the substrate surface of the first substrate, and the interference filter can be further miniaturized. ..

In the interference filter of this application example, it is preferable that the region other than the mirror region of the conductive layer is doped with particles having an electrical resistance value smaller than the electrical resistance value of the conductive layer.

In this application example, particles having a small electric resistance (hereinafter referred to as low resistance particles) are doped in a region other than the mirror region. For example, when a Si layer is used as the conductive layer, P particles and B particles are doped. By doping the low resistance particles other than the mirror region in this way, it is possible to suppress charging in the conductive layer and reduce the influence of charging. Further, since the low resistance particles are not doped in the mirror region, the reflection characteristics of the first reflective film are not changed by the low resistance particles, and the deterioration of the performance of the interference filter can be suppressed.

An optical filter device according to an application example according to the present invention is characterized by including an interference filter as described above and a housing for accommodating the interference filter.
In this application example, the influence of charging of the dielectric multilayer film in the interference filter can be suppressed as in the above-mentioned application example. Further, since the interference filter is housed in the housing, for example, it is possible to suppress the adhesion of foreign matter to the reflective film and protect the interference filter from impacts and the like.

The optical module of one application example according to the present invention is characterized by including an interference filter as described above and a circuit unit for driving the interference filter.
In this application example, the influence of charging of the dielectric multilayer film in the interference filter can be suppressed as in the above-mentioned application example. Therefore, it is not necessary to incorporate a circuit that performs complicated control in consideration of charging of the dielectric multilayer film as the circuit unit, the configuration of the circuit unit can be simplified, and the cost of the optical module can be reduced.

In the optical module of this application example, it is preferable that the circuit unit has a ground circuit having the first wiring electrode as a predetermined reference potential.
In this application example, since the circuit portion includes the ground circuit, when the conductive layer is charged, the electric charge of the conductive layer can be released from the first wiring electrode to the ground circuit.

An electronic device according to an application example of the present invention is characterized by including an interference filter as described above and a control unit that controls the interference filter.
In this application example, as in the application example described above, the influence of charging on the dielectric multilayer film can be excluded from the interference filter, and light of a desired wavelength can be stably output from the interference filter without performing complicated control. be able to. Therefore, it is possible to easily control the interference filter in the electronic device.

The plan view which shows the schematic structure of the tunable interference filter of 1st Embodiment. FIG. 5 is a cross-sectional view showing a schematic configuration of a tunable interference filter when the AA line of FIG. 1 is cut. The figure which shows the schematic structure of the 1st reflective film in 1st Embodiment, and the schematic structure of a 1st through hole. FIG. 5 is a cross-sectional view showing a schematic configuration of a tunable interference filter when the BB line of FIG. 1 is cut. The figure which shows the schematic structure of the 2nd reflective film in 1st Embodiment, and the schematic structure of the 2nd through hole. The figure for demonstrating the charge state of the 1st reflective film in the interference filter which has the conventional dielectric multilayer film in which the 1st through hole is not formed in the 1st reflective film. The figure for demonstrating the charged state of the 1st reflective film in 1st Embodiment. The figure which shows the 1st glass substrate of the 1st substrate formation process in the manufacturing method of the tunable interference filter of 1st Embodiment. The figure which shows the 2nd glass substrate of the 2nd substrate formation process in the manufacturing method of the tunable interference filter of 1st Embodiment. The plan view of the tunable interference filter in the second embodiment. FIG. 3 is a cross-sectional view of a part of a tunable interference filter cut along the CC line of FIG. FIG. 2 is a cross-sectional view showing a schematic configuration of a tunable interference filter according to a third embodiment. The cross-sectional view which shows the schematic structure of the optical filter device which concerns on 4th Embodiment. The figure which shows the structural example of the appearance of the printer in 5th Embodiment. The block diagram which shows the schematic structure of the printer of 5th Embodiment. The figure which shows the schematic structure of the spectroscope of the fifth embodiment. The figure which shows the shape example of the 1st through hole which concerns on modification 1. The figure which shows the other shape example of the 1st through hole which concerns on modification 1. FIG. The figure which shows the other shape example of the 1st through hole which concerns on modification 1. FIG. The figure which shows the other shape example of the 1st through hole which concerns on modification 1. FIG. FIG. 5 is a cross-sectional view showing an example of a connection configuration of the first extraction electrode and the first connection electrode according to the modified example 5. FIG. 5 is a cross-sectional view showing another example of the connection configuration of the first extraction electrode and the first connection electrode according to the modified example 5.

[First Embodiment]
Hereinafter, the optical module according to the first embodiment will be described.
FIG. 1 is a plan view showing a schematic configuration of the wavelength tunable interference filter 5 of the first embodiment. FIG. 2 is a cross-sectional view showing a schematic configuration of a tunable interference filter 5 obtained by cutting FIG. 1 along the line AA.
As shown in FIGS. 1 and 2, the tunable interference filter 5 includes a first substrate 51 and a second substrate 52. These first substrate 51 and second substrate 52 are integrally formed by being bonded by, for example, a bonding film 53 such as a plasma polymerized film containing siloxane as a main component.
The first substrate 51 is provided with the first reflective film 54, the second substrate 52 is provided with the second reflective film 55, and the first reflective film 54 and the second reflective film 55 have a mirror gap G. They are arranged so as to face each other. Further, the tunable interference filter 5 is provided with an electrostatic actuator 56 that changes the dimensions of the mirror gap G.
Hereinafter, the configuration of each part will be described in detail.

(Structure of First Substrate 51)
As shown in FIG. 2, the first substrate 51 includes an electrode arrangement groove 511 and a gap forming portion 512 formed by, for example, etching on a surface facing the second substrate 52. The first substrate 51 is formed to have a larger thickness than the second substrate 52, for example, and the first substrate 51 is suppressed when an electrostatic attraction is applied by the electrostatic actuator 56.
Further, one end side of the first substrate 51 (for example, sides C5-C6 in FIG. 1) protrudes from one end side (sides C1-C2) of the second substrate 52, and the wavelength tunable interference filter 5 is provided in, for example, a package housing. It can be used as a fixing part when fixing to a base or the like.

The electrode arrangement groove 511 is formed in a substantially annular shape centered on a predetermined filter central axis O in a plan view (hereinafter, simply referred to as a plan view) when the first substrate 51 is viewed from the substrate thickness direction. Further, on the first substrate 51, a drawer groove 511A having the same depth as the electrode arrangement groove 511 extends from the electrode arrangement groove 511 toward the sides C3-C4.

The gap forming portion 512 is provided inside the electrode arrangement groove 511 (on the O side of the filter central axis) in a plan view, and is formed so as to project toward the second substrate 52 side as shown in FIG. The protruding tip surface of the gap forming portion 512 is a flat surface, and is maintained parallel to or substantially parallel to the movable surface 521A of the movable portion 521 of the second substrate 52.

FIG. 3 is a diagram showing a schematic configuration of the first reflective film 54 and the first through hole 543. FIG. 4 is a schematic cross-sectional view when the line BB of FIG. 1 is cut.
The first reflective film 54 is provided over the surface of the first substrate 51 facing the second substrate 52. That is, the first reflective film 54 is formed so as to cover substantially the entire surface of the first substrate 51 facing the second substrate 52 (other than the portion where the first through hole 543 described later is provided).
The first reflective film 54 is composed of a plurality of film materials having reflection characteristics and transmission characteristics for light in a predetermined wavelength range, and the film materials are dielectrics having different refraction characteristics with respect to the light. It is a body multilayer film. Specifically, as shown in FIG. 3, in the first reflective film 54, a metal oxide film (hereinafter abbreviated as oxide film 541) which is an insulating layer and a metal film 542 which is a conductive layer are alternately laminated. It is a laminated body composed of. _{For example, in the present embodiment, SiO 2} is used as the oxide film 541 of the high refraction layer, and Si, which is a metalloid, is used as the metal film 542 of the low refraction layer. The first reflective film 54 of such a dielectric multilayer film has high reflection characteristics in the near infrared to infrared region.
The layer forming the outermost surface of the first reflective film 54 facing the second substrate 52 is the metal oxide film 541.

Further, the first reflective film 54 is provided with at least a part of the first through hole 543. The first through hole 543 is along the direction from the outermost surface of the first reflective film 54 toward the first substrate 51 (the thickness direction of the first reflective film 54 and the laminating direction of the metal oxide film 541 and the metal film 542). It is a formed hole. In the present embodiment, the first through hole 543 is formed so as to penetrate the first reflective film 54, and the substrate surface of the first substrate 51 (the surface facing the second substrate 52) is formed from the first through hole 543. Be exposed. That is, the bottom surface 543B of the first through hole 543 is the first substrate 51.

Further, in the present embodiment, the first through hole 543 is formed by communicating through holes formed in each of the oxide film 541 and each metal film 542. Here, the pore diameter of the through hole on the outermost surface of the first reflective film 54 (the oxide film 541 located at the position farthest from the first substrate 51) is the largest, and the pore diameter of the through hole gradually decreases toward the layer immediately below (the pore diameter of the through hole becomes smaller). Stepped). Then, in a plan view from the thickness dimension, each through hole is arranged inside the through hole of the layer directly above.
For example, the through hole (first through hole 541A) provided in the outermost surface oxide film 541 penetrates the metal film 542 formed immediately below the outermost surface oxide film 541 (on the first substrate 51 side). It communicates with the hole (second through hole 542A) and forms a part of the first through hole 543. The hole diameter L1 of the first through hole 541A is larger than the hole diameter L2 of the second through hole 542A, and the second through hole 542A is arranged inside the first through hole 541A in a plan view. Therefore, a part of the upper surface (the surface on the second substrate 52 side) of the metal film 542 immediately below the outermost oxide film 541 and the side surface of the metal film 542 are exposed inside the first through hole 543. become.
The same applies to the other metal film 542, and by providing the second through hole 542A having a hole diameter smaller than the hole diameter of the first through hole 541A of the oxide film 541 arranged directly above, one of the upper surfaces of each metal film 542. The portion and the side surface are exposed to the first through hole 543.
Further, the position where the first through hole 543 is provided may be any region other than the gap forming portion 512, and in the present embodiment, the first through hole 543 is provided in the drawer groove 511A. It is provided.

The first electrode 561 constituting the electrostatic actuator 56 is arranged on the first reflective film 54 formed over substantially the entire surface of the first substrate 51 facing the second substrate 52.
Specifically, the first electrode 561 is arranged on the first reflective film 54 formed on the bottom surface of the electrode arrangement groove 511 of the first substrate 51. The first electrode 561 is formed in a substantially annular shape along, for example, the electrode arrangement groove 511.
In this embodiment, one first electrode 561 is provided, but for example, two or more electrodes concentric with the filter central axis O may be provided. Further, the shape of the first electrode 561 may be, for example, a configuration in which a notch portion that communicates inside and outside the ring is provided in a part thereof. In this case, another electrode independent of the first electrode 561 (for example, a capacitance detection electrode arranged on the gap forming portion 512) may be provided through the notch.

A first lead electrode 563 (see FIG. 1) extending along the side C3-C4 side along the lead groove 511A is connected to the first electrode 561. In the present embodiment, the first electrode 561 is an electrode connected to a ground circuit or the like and maintained at a reference potential (for example, 0 V), and the first extraction electrode 563 corresponds to the first wiring electrode of the present invention. do.
The first extraction electrode 563 is connected to the first connection electrode 565 provided on the second substrate 52 side in the extraction groove 511A.

Here, as shown in FIG. 3, the first extraction electrode 563 is connected to the first through hole 543 in the extraction groove 511A. Specifically, the first extraction electrode 563 is formed on the oxide film 541 constituting the outermost surface of the first reflection film 54, on the inner peripheral surface 543A of the first through hole 543, and on the bottom surface 543B of the first through hole 543. It is formed over and covers the surface of the first through hole 543. Here, a configuration that covers the hole inner peripheral surface 543A of the first through hole 543 and the bottom surface 543B of the first through hole 543 is illustrated, but at least covers the hole inner peripheral surface 543A of the first through hole 543. Just do it. Further, the inside of the hole of the first through hole 543 may be filled (filled) by the first lead-out electrode 563, and only a part of the first substrate 51 side is the electrode material of the first lead-out electrode 563. The configuration may be filled with.
As a result, a part of the upper surface and the side surface of the metal film 542 exposed from the first through hole 543 are covered with the first extraction electrode 563 to conduct conduction.

Returning to FIGS. 1 and 2, among the surfaces of the first substrate 51 facing the second substrate 52, the first joint portion 513 is provided on the surface on which the electrode arrangement groove 511, the gap forming portion 512, and the drawer groove 511A are not formed. Be done. The first bonding portion 513 is bonded to the second substrate 52 via the bonding film 53.
Further, as shown in FIGS. 1 and 4, a part of the first extraction electrode 563 (electrode connection portion 563A) extends to the first joint portion 513, and the second substrate is formed at the first joint portion 513. It is connected to the first connection electrode 565 provided on the 52.

In this embodiment, an example is shown in which the gap forming portion 512 is located closer to the second substrate 52 than the electrode arrangement groove 511. For example, depending on the wavelength range of the light transmitted through the tunable interference filter 5, the electrode arrangement is performed. The groove 511 may be located closer to the second substrate 52 than the gap forming portion 512. That is, a recess may be formed inside the electrode arrangement groove 511 (on the O side of the filter center axis) in a plan view, and the first reflective film 54 may be provided on the bottom surface of the recess.

(Structure of Second Substrate 52)
The second substrate 52 corresponds to the substrate of the present invention. In the second substrate 52, one end side (sides C3-C4 side) of the second substrate 52 projects outward from the sides C7-C8 of the first substrate 51 to form an electrical component portion 560. Further, a second reflective film 55 and a second electrode 562 are provided on the surface of the second substrate 52 facing the first substrate 51.
Then, on the surface of the second substrate 52 opposite to the first substrate 51, a concave, for example, annular groove is formed on the first substrate 51 side, so that the movable portion 521 and the movable portion 521 are formed. A holding portion 522 that surrounds the outer periphery and a substrate outer peripheral portion 523 provided outside the holding portion 522 are formed.

The movable portion 521 is formed to have a thickness larger than that of the holding portion 522. For example, in the present embodiment, the movable portion 521 is formed to have the same thickness dimension as the outer peripheral portion 523 of the substrate. The movable portion 521 faces the gap forming portion 512 in a plan view and is formed to have a diameter dimension larger than the diameter dimension of the outer peripheral edge of the first electrode 561.

The holding portion 522 is a diaphragm that surrounds the movable portion 521, and is formed to have a thickness smaller than that of the movable portion 521. Such a holding portion 522 is more easily bent than the movable portion 521, and the movable portion 521 can be displaced toward the first substrate 51 by a slight electrostatic attraction. At this time, since the movable portion 521 has a larger thickness and rigidity than the holding portion 522, the shape of the movable portion 521 changes even when the movable portion 521 is pulled toward the first substrate 51 by an electrostatic attraction. It can be suppressed to some extent.
In the present embodiment, the diaphragm-shaped holding portion 522 is illustrated, but the present invention is not limited to this, and for example, a beam-shaped holding portion arranged at equal intervals around the filter central axis O of the movable portion 521. May be provided.

The outer peripheral portion 523 of the substrate is a portion that holds the outer peripheral side of the holding portion 522. A bonding film 53 is bonded to a portion of the outer peripheral portion 523 of the substrate facing the first bonding portion 513 of the first substrate 51, and is bonded to the first substrate 51 via the bonding film 53.

Then, the second reflective film 55 is provided over the surface of the second substrate 52 facing the first substrate 51. That is, the second reflective film 55 is provided so as to cover substantially the entire surface of the second substrate 52 facing the first substrate 51 (a portion other than the second through hole 553 described later).
FIG. 5 is a diagram showing a schematic configuration of the second reflective film 55 and the second through hole 553.
Similar to the first reflective film 54, the second reflective film 55 is a laminate (dielectric) in which a high refractive index layer having a high refractive index for light having a predetermined wavelength and a low refractive index layer having a low refractive index are alternately laminated. It is a multilayer film), and is composed of a metal oxide film (referred to as an oxide film 551) which is an insulating layer and a metal film 552 which is a conductive layer. In the present embodiment, similarly to the first reflective film 54, an oxide film 551 (for example, SiO ₂ ) is used as the high refraction layer, and a metal film 552 (for example, Si) is used as the low refraction layer.
Of the first reflective film 54 and the second reflective film 55, the region M facing the tip surface of the gap forming portion 512 is the mirror region M. The mirror region M is a region in which incident light is multiple-reflected between the first reflection film 54 and the second reflection film 55, and light having a wavelength corresponding to the mirror gap G is intensified by interference and emitted from the mirror region M. NS.

Further, similarly to the first reflective film 54, the second reflective film 55 is provided with a second through hole 553 at least in a part thereof. The second through hole 553 is formed along the direction from the outermost surface of the second reflective film 55 toward the second substrate 52 (the thickness direction of the second reflective film 55 and the laminating direction of the oxide film 551 and the metal film 552). It is a hole made. Further, the second through hole 553 is formed in a stepped shape in which the hole diameter of the through hole of each layer becomes smaller toward the second substrate 52, similarly to the first through hole 543.
Therefore, a part of the upper surface (the surface on the first substrate 51 side) and the side surface of each metal film 552 are exposed in the second through hole 553.
Further, similarly to the first through hole 543, the second through hole 553 may be provided anywhere as long as it is in a region other than the gap forming portion 512. In the present embodiment, the second through hole 553 is provided at a position facing the drawer groove 511A.

Then, the second electrode 562 is arranged on the second reflective film 55 of the second substrate 52. The second electrode 562 is formed in the same shape as the first electrode 561, for example, and is provided at a position facing the first electrode 561.
Further, from the outer peripheral edge of the second electrode 562, a second drawer electrode 564 (see FIG. 1) that passes through a region facing the drawer groove 511A and extends to the electrical component portion 560 is provided.

Further, on the surface of the second substrate 52 facing the first substrate 51, a first connection electrode 565 provided from a region facing the drawer groove 511A to the electrical component portion 560 is provided. The first connection electrode 565 corresponds to the second wiring electrode of the present invention and is also connected to the second through hole 553. Specifically, similarly to the first extraction electrode 563 connected to the first through hole 543, the first connection electrode 565 is formed from the hole inner peripheral surface 553A of the second through hole 553 to the bottom surface 553B. It conducts to each metal film 552 exposed from the second through hole 553.
Further, as shown in FIGS. 1 and 4, a part of the first connection electrode 565 (electrode connection part 565A) faces a part of the first joint part 513 (the electrode connection part 563A of the first extraction electrode 563). When the first substrate 51 and the second substrate 52 are joined by the bonding film 53, they are made conductive by coming into contact with the first extraction electrode 563. As a result, the first electrode 561, the first extraction electrode 563, the first connection electrode 565, the metal films 542 of the first reflection film 54, and the metal films 552 of the second reflection film 55 are electrically connected to each other to have the same potential. ..

[Charging of each reflective film when driving the tunable interference filter 5]
Next, charging of the dielectric multilayer film (first reflective film 54 and second reflective film 55) when the tunable interference filter 5 as described above is driven will be described.
Here, the charging of the first reflective film 54 when a voltage is applied to the electrostatic actuator 56 will be described, and the charging of the second reflective film 55 is the same as that of the first reflective film 54, so the description thereof will be omitted.

In the variable wavelength interference filter 5 as described above, the second extraction electrode 564 and the first connection electrode 565 are connected to a drive circuit (driver circuit) for driving the variable wavelength interference filter 5, and the drive circuit causes electrostatic charge. The voltage applied between the first electrode 561 and the second electrode 562 constituting the actuator 56 is controlled. As a result, an electrostatic attraction acts between the first electrode 561 and the second electrode 562, the holding portion 522 is deformed, the movable portion 521 is displaced toward the first substrate 51, and the dimensions of the mirror gap G are changed. It becomes possible.

FIG. 6 is a diagram for explaining the charged state of the first reflective film 54 when the first through hole 543 is not formed in the first reflective film 54 (conventional interference filter). In FIG. 6, for simplification of the description, only the layers of the oxide film 541 and the metal film 542 are shown.
As described above, when the electrostatic actuator 56 is applied, an electric charge corresponding to the applied voltage is accumulated (charged) in the first electrode 561. As a result, as shown in FIG. 6, local polarization is also generated in the first reflective film 54 arranged immediately below the first electrode 561. In the example shown in FIG. 6, the first electrode 561 is positively charged by the application of a voltage, which causes local polarization in the oxide film 541 arranged on the outermost surface of the first reflection film 54 directly below. Then, of the oxide film 541, the area directly below the first electrode 561 is negatively charged. In this case, a positive charge is accumulated and charged on the metal film 542 arranged immediately below the oxide film 541.
Although such polarization is gradually relaxed via the metal film 542, it is accumulated in the charged metal film 542 (particularly the metal film 542 arranged near the outermost surface of the first reflection film 54). A phenomenon occurs in which the mirror gap G gradually narrows due to the influence of the electric charge. That is, the area that functions as the electrostatic actuator 56 is apparently expanded.

FIG. 7 is a diagram for explaining the charged state of the first reflective film 54 in the present embodiment. Note that FIG. 7 shows only one layer each of the oxide film 541 and the metal film 542 for the sake of simplification of the description.
In the present embodiment, as a drive circuit, a circuit that sets the first connection electrode 565 to a reference potential (for example, a ground circuit that applies 0 V to the first connection electrode 565) is used, as shown in FIG. 7, a metal. The electric charge accumulated in the film 542 can be released to the first connection electrode 565 connected to the ground circuit via the first through hole 543 and the first connection electrode 565. As a result, the charging of each metal film 542 is suppressed, and the influence of the charging as described above is also suppressed.

Although the charging of the first reflective film 54 has been described with reference to FIGS. 6 and 7, the same applies to the second reflective film 55. That is, even when an electric charge is accumulated in each metal film 552 of the second reflective film 55, the electric charge can be released from the second through hole 553 to the first connecting electrode 565.

[Manufacturing method of tunable interference filter 5]
Next, a method for manufacturing the tunable interference filter 5 as described above will be described.
In the manufacture of the variable wavelength interference filter 5, the first glass substrate M1 (see FIG. 8) for forming the first substrate 51 and the second glass substrate M2 (see FIG. 9) for forming the second substrate 52 are used. Prepare and carry out the first substrate forming step and the second substrate forming step. After that, a substrate bonding step is carried out to bond the first glass substrate M1 processed by the first substrate forming step and the second glass substrate M2 processed by the second substrate forming step. Further, a cutting step is carried out, and the first glass substrate M1 and the second glass substrate M2 are separated into individual pieces to form the tunable interference filter 5.
Hereinafter, each step will be described with reference to the drawings.

(First substrate forming process)
FIG. 8 is a diagram showing a first glass substrate in the first substrate forming step.
In the substrate forming step, first, both sides of the first glass substrate M1 which is the manufacturing material of the first substrate 51 are precision-polished until the surface roughness Ra becomes 1 nm or less, and the thickness is made, for example, 500 μm.

Next, as shown first in FIG. 8, the substrate surface of the first glass substrate M1 is processed by etching.
Specifically, using a resist pattern patterned by a photolithography method as a mask, wet etching using, for example, a hydrofluoric acid system (BHF or the like) is repeatedly applied to the first glass substrate M1. First, the forming positions of the electrode arrangement groove 511, the gap forming portion 512, and the drawing groove 511A (omitted in FIG. 8) are etched to the position of the protruding tip of the gap forming portion 512. After that, the electrode arrangement groove 511 and the extraction groove 511A are etched to a desired depth position.

Next, as shown in the second part of FIG. 8, the first reflective film 54 is formed on the entire surface of the first glass substrate M1 on the one side on which the electrode arrangement groove 511, the gap forming portion 512, and the drawer groove 511A are formed. Form.
In the formation of the first reflective film 54, the oxide film 541 and the metal film 542 constituting the first reflective film 54 are alternately laminated and formed by, for example, a sputtering method or a thin film deposition method.
At this time, even if the first glass substrate M1 has a step having a steep slope or an edge due to wet etching or the like, the inclination of the step portion is gentle because each dielectric layer is laminated when the dielectric multilayer film is formed. become. Therefore, breakage when forming each electrode 561,563 on the first reflective film 54 is suppressed.

Next, as shown in the third position of FIG. 8, the first through hole 543 is formed in the first reflective film 54 at a predetermined position (in this embodiment, the drawer groove 511A).
In the formation of the first through hole 543, first, a resist is formed on the first reflective film 54, and a pattern for forming the first through hole 541A having a hole diameter L1 is formed in the oxide film 541 located on the outermost surface. Then, the metal film 542 immediately below is used as an etching stopper, and the oxide film 541 on the outermost surface is wet-etched.
After that, the resist is removed to form a resist that covers the first reflective film 54 again. Then, a pattern for forming the second through hole 542A having the hole diameter L2 (L2 <L1) is formed in the first through hole 541A of the oxide film 541 previously formed by etching. After that, the metal film 542 directly under the oxide film 541 on the outermost surface is etched by using the oxide film 541 directly under the metal film 542 as an etching stopper.
After that, the process is repeated in the same manner, and the hole diameter of the through hole of each layer is gradually reduced to form the first through hole 543 having a stepped shape at the position of each layer.
Here, for the sake of simplification of the description, the side surfaces of each oxide film 541 and each metal film 542 are substantially parallel to the thickness direction (the stacking direction of the oxide film 541 and the metal film 542), that is, first. The figure which is substantially perpendicular to the substrate surface of the substrate 51 is shown. However, in reality, in the formation of the through holes 541A and 542A by wet etching, side etching occurs, so that the side surfaces of each oxide film 541 and each metal film 542 are inclined with respect to the stacking direction.

After that, the electrode materials of the first electrode 561 and the first extraction electrode 563 are formed on the first glass substrate M1 by a vapor deposition method, a sputtering method, or the like. Then, the formed electrode material is patterned. At this time, the electrode material is also formed in the first through hole 543, so that the first electrode 561, the first extraction electrode 563, and each metal film 542 are electrically conducted.
As a result, as shown in the fourth aspect of FIG. 8, the first glass substrate 51 in which the first reflective film 54, the first electrode 561, and the first substrate 51 provided with the first extraction electrode 563 are arranged in a plurality of arrays is arranged. M1 is formed.

(Second substrate forming process)
FIG. 9 is a diagram showing a state of the second glass substrate M2 in the second substrate forming step.
In the second substrate forming step, first, both sides of the second glass substrate M2, which is the manufacturing material of the second substrate 52, are precision-polished until the surface roughness Ra becomes 1 nm or less, and the thickness is made, for example, 500 μm.

Then, a Cr / Au layer is formed on the surface of the second glass substrate M2, and the Cr / Au layer is used as an etching mask, and a region corresponding to the holding portion 522 is etched using, for example, a hydrofluoric acid system (BHF or the like). .. After that, by removing the Cr / Au layer used as the etching mask, the substrate shape of the second substrate 52 is formed as shown in the first of FIG.

Next, as shown in the second part of FIG. 9, the second reflective film 55 is formed. The second reflective film 55 can also be formed by the same method as the first reflective film 54, and the oxide film 551 and the metal film 552 forming the second reflective film 55 are alternately formed by a sputtering method, a vapor deposition method, or the like. The film is formed in a laminated manner.

Next, as shown in the third position of FIG. 9, a second through hole 553 is formed in the second reflective film 55 at a predetermined position (in the present embodiment, a position facing the drawer groove 511A).
The formation of the second through hole 553 is the same as that of the first through hole 543, and the description thereof is omitted here.

After that, the second electrode 562, the second extraction electrode 564, and the first connection electrode 565 are formed on the second glass substrate M2. The formation of the second electrode 562, the second extraction electrode 564, and the first connection electrode 565 is performed in the same process as the formation of the first electrode 561, and after the electrode material is formed by a vapor deposition method, a sputtering method, or the like. , The deposited electrode material is patterned. At this time, the electrode material is also formed in the second through hole 553, so that the first connection electrode 565 and each metal film 552 are electrically conductive.
As described above, as shown in the fourth aspect of FIG. 9, the second substrate 52 provided with the second reflective film 55, the second electrode 562, the second extraction electrode 564, and the first connection electrode 565 is arranged in a plurality of arrays. The second glass substrate M2 is formed.

(Wafer bonding process)
Next, the substrate bonding step and the cutting step will be described.
In the substrate bonding step, first, polyorganosiloxane is mainly used in the first bonding portion 513 of the first glass substrate M1 and the portion of the outer peripheral portion 523 of the second glass substrate M2 that is bonded to the first bonding portion 513. The plasma polymerized film as a component is formed by a plasma CVD method or the like.
_{Then, O 2} plasma treatment or UV treatment is performed in order to impart activation energy to each plasma polymer film of the first glass substrate M1 and the second glass substrate M2. In _{the case of O 2} plasma treatment, it is _{carried out for 30 seconds under the conditions of O 2} flow rate 1.8 × 10 ^-3 (m ³ / h), pressure 27 Pa, and RF power 200 W. In the case of UV treatment, excimer UV (wavelength 172 nm) is used as a UV light source for 3 minutes.
After applying activation energy to the plasma polymerized film, the alignment of the first glass substrate M1 and the second glass substrate M2 is adjusted, and the first glass substrate M1 and the second glass substrate M2 are overlapped with each other via the plasma polymerized film. Together, a load of, for example, 98 (N) is applied to the joint for 10 minutes. As a result, the first glass substrate M1 and the second glass substrate M2 are joined to each other.
At this time, a part of the first extraction electrode 563 and a part of the first connection electrode 565 arranged at the first joint portion 513 come into contact with each other and are pressed in a direction close to each other. The extraction electrode 563 and the first connection electrode 565 are connected.

(Cutting process)
Next, the cutting process will be described.
In the cutting step, the first substrate 51 and the second substrate 52 are cut out in chip units to form a tunable interference filter 5 as shown in FIGS. 1 and 2. For cutting the first glass substrate M1 and the second glass substrate M2, for example, scribe break, laser cutting, or the like can be used.

[Action and effect of this embodiment]
The wavelength tunable interference filter 5 of the present embodiment is a first reflection composed of a laminated body in which an oxide film 541 and a metal film 542 are laminated over substantially the entire surface of the first substrate 51 facing the second substrate 52. A film 54 is formed. Such a first reflective film 54 eliminates the need for a patterning step such as lift-off, and improves manufacturing efficiency.
Then, the first reflective film 54 is provided with a first through hole 543 in which the metal film 542 is exposed, and the first extraction electrode 563 provided on the surface of the first reflective film 54 is connected to the first through hole 543. Then, it conducts to the metal film 542 exposed from the first through hole 543. Therefore, even when each metal film 542 of the first reflective film 54 is charged when a voltage is applied to the electrostatic actuator 56, the electric charge of the metal film 542 can be released to the first extraction electrode 563.
Thereby, for example, the influence of charging of the first reflective film 54, such as the mirror gap G gradually becoming smaller, can be suppressed.

The same applies to the second substrate 52, and a second reflective film composed of a laminate in which an oxide film 551 and a metal film 552 are laminated over substantially the entire surface of the second substrate 52 facing the first substrate 51. 55 is formed. Therefore, the patterning step by lift-off or the like becomes unnecessary, and the manufacturing efficiency of the second substrate 52 can be improved.
Then, the second reflective film 55 is provided with a second through hole 553 in which the metal film 552 is exposed, and the first connection electrode 565 provided on the surface of the second reflective film 55 is connected to the second through hole 553. Then, it conducts to the metal film 552 exposed from the second through hole 553. Therefore, even when each metal film 552 of the second reflective film 55 is charged when a voltage is applied to the electrostatic actuator 56, the electric charge of the metal film 552 can be released to the first connection electrode 565.
Thereby, for example, the influence of charging of the second reflective film 55, such as the mirror gap G gradually becoming smaller, can be suppressed.

In the present embodiment, the first through hole 543 is the second of the first through hole 541A formed in the oxide film 541 forming the first reflection film 54 and the metal film 542 formed directly under the oxide film 541. The second through hole 542A is located inside the first through hole 541A in a plan view including the through hole 542A. Therefore, a part of the upper surface and the side surface of the metal film 542 are exposed to the first through hole 543. In this case, when the first extraction electrode 563 extending from the first reflection film 54 to the inside of the first through hole 543 is formed by a method such as sputtering, the first extraction electrode 563 is not only on the side surface of the metal film 542 but also on the side surface. It will also come into contact with a part of the upper surface. Therefore, the inconvenience of disconnection between the first extraction electrode 563 and each metal film 542 can be suppressed, and the electric charge accumulated in the metal film 542 can be released to the first extraction electrode 563.
The same applies to the second through hole 553, in which through holes are provided in each layer of the oxide film 551 and the metal film 552, and the through holes in each layer are formed in a stepped shape in which the hole diameter becomes smaller toward the second substrate 52. As a result, the inconvenience of disconnection between the first connection electrode 565 and each metal film 552 can be suppressed, and the electric charge accumulated in the metal film 552 can be released to the first connection electrode 565.

In the present embodiment, the first extraction electrode 563 connected to the first through hole 543 and the first connection electrode 565 connected to the second through hole 553 are connected.
As a result, by connecting the first connection electrode 565 extending to the electrical component 560 to, for example, a ground circuit or the like, the electric charges accumulated in both the first reflection film 54 and the second reflection film 55 can be released. can. That is, as compared with the case where the electrode terminal for releasing the electric charge of the first reflective film 54 and the electrode terminal for releasing the electric charge accumulated in the second reflective film 55 are individually provided, the wavelength variable interference filter 5 The configuration can be simplified.

[Second Embodiment]
Next, the second embodiment will be described.
In the first embodiment, in a part of the first joint portion 513, a part of the first extraction electrode 563 and a part of the first connection electrode 565 are brought into contact with each other.
On the other hand, the second embodiment is different from the first embodiment in that the first drawer electrode 563 and the first connection electrode 565 are connected between the drawer groove 511A and the second substrate 52. ..
In the following description, the configurations already described will be designated by the same reference numerals, and the description thereof will be omitted or simplified.

FIG. 10 is a plan view of the wavelength tunable interference filter 5A according to the second embodiment, and FIG. 11 is a cross-sectional view of a part of the wavelength tunable interference filter 5A cut along the line CC of FIG.
In the wavelength tunable interference filter 5A of the present embodiment, as in the first embodiment, the first reflective film formed of the dielectric multilayer film covers substantially the entire surface of the first substrate 51 facing the second substrate 52. 54 is formed.
Then, as in the first embodiment, a first through hole 543 penetrating the first reflective film 54 is formed in a part of the drawer groove 511A.
Note that FIG. 11 shows an example in which the inner peripheral surface 543A of the first through hole 543 is parallel to the stacking direction of the oxide film 541 and the metal film 542, but as in the first embodiment, each layer has a stepped shape. The first through hole 543 may have a smaller hole diameter as it approaches the first substrate 51.

In the present embodiment, the first substrate 51 includes a protruding portion 514 that projects toward the second substrate 52 from the surface of the drawer groove 511A that is the bottom surface 543B of the first through hole 543 facing the second substrate 52. There is. The protruding tip surface 514A of the protruding portion 514 is parallel to or substantially parallel to the surface of the second substrate 52 facing the first substrate 51.
Then, the first extraction electrode 563 is connected to the first through hole 543 as in the first embodiment, and further, the protrusion tip surface 514A of the protrusion 514 from the hole inner peripheral surface 543A of the first through hole 543. Cover.

On the other hand, in the second substrate 52, as in the first embodiment, the second reflective film 55 is formed over substantially the entire surface of the surface facing the first substrate 51.
Then, in the present embodiment, the second through hole 553 is provided at a position overlapping the first through hole 543 in a plan view. Further, in a plan view, the outer peripheral edge of the bottom surface 553B of the second through hole 553 is located outside the protruding tip surface 514A of the protruding portion 514, and the protruding portion 514 is inserted into the second through hole 553.
Further, the first connection electrode 565 is connected to the second through hole 553 as in the first embodiment, and covers the bottom surface 553B from the inner peripheral surface 553A of the second through hole 553.

Here, in the present embodiment, when the first substrate 51 and the second substrate 52 are joined by the bonding film 53, the protruding dimension of the protruding portion 514, the thickness dimension of the first extraction electrode 563, and the first connection electrode 565 The total thickness dimension is formed to be equal to the dimension from the surface of the drawer groove 511A facing the second substrate 52 to the surface of the second substrate 52 facing the drawer groove 511A.
Therefore, when the first substrate 51 and the second substrate 52 are joined by the bonding film 53, the first connection electrode 565 provided on the bottom surface 553B of the second through hole 553 and the protruding tip surface 514A of the protruding portion 514 are provided. It comes into contact with the first extraction electrode 563. As a result, each metal film 542 of the first reflection film 54, each metal film 552 of the second reflection film 55, the first extraction electrode 563, and the first connection electrode 565 are conducted.

[Action and effect of the second embodiment]
In the tunable interference filter 5A of the present embodiment, the tunable interference filter 5A projects from the bottom surface 543B (corresponding to the first bottom surface in the present invention) of the first through hole 543 of the first substrate 51 toward the second substrate 52 and reaches the protruding tip surface 514A. A protrusion 514 is provided so that a part of the first extraction electrode 563 extends. Further, the second through hole 553 is provided at a position overlapping the protruding portion 514 in a plan view, and a part of the first connection electrode 565 is provided on the bottom surface 553B (corresponding to the second bottom surface in the present invention) of the second through hole. Will be extended. Then, when the first substrate 51 and the second substrate 52 are joined by the bonding film 53, the protruding portion 514 is inserted into the second through hole 553, and the first extraction electrode 563 provided on the protruding tip surface 514A is formed. , Is connected to the first connection electrode 565 provided on the bottom surface 553B of the second through hole 553.

In such a configuration, the first substrate 51 and the second substrate 52 can be brought close to each other, and the size of the tunable interference filter 5A can be reduced.
That is, in a configuration in which the first extraction electrode 563 provided on the protrusion tip surface 514A of the protrusion 514 is connected to the first connection electrode 565 of the second substrate 52, the second reflective film 55 which is a dielectric multilayer film is used. It is conceivable to connect the first extraction electrode 563 of the protrusion 514 to the first connection electrode 565. However, the first reflective film 54 and the second reflective film 55 composed of the dielectric multilayer film have a thickness dimension of more than 1 μm. Therefore, in this case, the distance between the first substrate 51 and the second substrate 52 is the protruding dimension of the protruding portion 514, the thickness dimension of the second reflective film 55, the thickness dimension of the first extraction electrode 563, and the first connection electrode 565. Only the total thickness dimension will be opened.
On the other hand, in the configuration in which the protruding portion 514 is inserted into the second through hole 553 to connect the first extraction electrode 563 and the first connection electrode 565, the thickness dimension of the second reflective film 55 is larger than that in the above configuration. Therefore, the distance between the first substrate 51 and the second substrate 52 can be reduced.

Further, in the present embodiment, the protruding portion 514 projects from the bottom surface 543B of the first through hole 543 toward the second substrate 52 side.
Therefore, the distance between the first substrate 51 and the second substrate 52 is reduced by the thickness dimension of the first reflective film 54 as compared with the case where the protruding portion 514 is formed on the first reflective film 54 which is a dielectric multilayer film. can.

[Third Embodiment]
Next, the third embodiment will be described.
In the first embodiment and the second embodiment described above, an example is shown in which the metal film 542 of the first reflective film 54 and the metal film 552 of the second reflective film 55 are film layers having uniform electrical resistance. On the other hand, the third embodiment differs from the above embodiment in that the electrical resistance of the metal film 542,552 is partially different.

FIG. 12 is a cross-sectional view showing a schematic configuration of the wavelength tunable interference filter 5B according to the third embodiment.
In the present embodiment, the first reflective film 54 and the second reflective film 55 have different electrical resistances in the metal films 542 and 552 between the inside of the mirror region M and the region other than the mirror region M (outer region N). ..
Specifically, in the outer region N of the metal film 542,552, particles having an electric resistance higher than that of the metal or metalloid constituting the metal film 542,552 (low resistance particles) are present. It is doped. For example, in this embodiment, Si is used as the metal film 542,552. In this case, in the outer region N, low resistance particles having a higher electric resistance value than Si such as P and B are doped. Any method may be used as the doping method for these low resistance particles, and examples thereof include ion implantation and thermal diffusion.
The metal film 542,552 of the mirror region M is not doped with the low resistance particles as described above. Therefore, the reflection characteristics of the first reflection film 54 and the second reflection film 55 in the mirror region M are uniformly maintained, and the deterioration of the characteristics due to the doped particles is suppressed.

[Action and effect of the third embodiment]
In the present embodiment, the metal film 542 of the first reflective film 54 and the metal film 552 of the second reflective film 55, which are conductive layers, have low resistances such as P and B, which have higher electric resistance values than Si in the outer region N. The particles are doped. By doping the outer region N with low-resistance particles in this way, it becomes difficult for electric charges to move in the metal film 542,552, and it becomes difficult for electric charges to occur. Therefore, the influence of charging of the first reflective film 54 and the second reflective film 55 can be suppressed.
On the other hand, in the mirror region M, since the low resistance particles are not doped, the reflection characteristics of the first reflection film 54 and the second reflection film 55 do not change due to the low resistance particles. Therefore, the performance deterioration of the tunable interference filter 5B can be suppressed.

[Fourth Embodiment]
Next, as a fourth embodiment, an optical filter device including wavelength tunable interference filters 5, 5A and 5B as shown in the first to third embodiments will be described.
FIG. 13 is a cross-sectional view showing a schematic configuration of the optical filter device 600 according to the fourth embodiment.
As shown in FIG. 13, the optical filter device 600 includes a housing 610 and a wavelength tunable interference filter 5 housed inside the housing 610. Although the example in which the wavelength tunable interference filter 5 shown in the first embodiment is housed in the housing 610 is shown here, the wavelength tunable interference filter 5B of the second embodiment may be housed.

As shown in FIG. 13, the housing 610 includes a base 620 and a lid 630. By joining these base 620 and lid 630, an accommodation space is formed inside, and the wavelength tunable interference filter 5 is accommodated in this accommodation space. In this embodiment, the optical filter device 600 in which the wavelength variable interference filter 5 shown in the first embodiment is housed is illustrated, but the wavelength variable interference filter 5A of the second embodiment and the wavelength of the third embodiment are exemplified. The variable interference filter 5B may be housed.

(Base configuration)
The base 620 is made of, for example, ceramic or the like. The base 620 includes a pedestal portion 621 and a side wall portion 622.
The pedestal portion 621 is configured in a flat plate shape having, for example, a rectangular outer shape in a filter plan view, and a tubular side wall portion 622 rises from the outer peripheral portion of the pedestal portion 621 toward the lid 630.

The pedestal portion 621 includes an opening 623 that penetrates in the thickness direction. The opening 623 includes a region that overlaps the first reflective film 54 and the second reflective film 55 in a plan view of the pedestal portion 621 viewed from the thickness direction in a state where the tunable interference filter 5 is housed in the pedestal portion 621. It is provided as follows.
Further, a glass member 627 covering the opening 623 is joined to the surface of the pedestal portion 621 opposite to the lid 630 (base outer surface 621B). For joining the pedestal portion 621 and the glass member 627, for example, low melting point glass joining using a glass frit (low melting point glass) which is a piece of rapidly cooled glass obtained by melting a glass raw material at a high temperature, bonding with an epoxy resin or the like, etc. Can be used. In the present embodiment, the inside of the accommodation space is maintained airtight while being maintained under reduced pressure. Therefore, it is preferable that the pedestal portion 621 and the glass member 627 are joined by using a low melting point glass joint.

Further, on the inner surface (base inner side surface 621A) of the pedestal portion 621 facing the lid 630, an inner terminal portion 624 connected to the first connection electrode 565 and the second extraction electrode 564 of the tunable interference filter 5 is provided. There is. The inner terminal portion 624, the first connection electrode 565, and the second extraction electrode 564 are connected by wire bonding using, for example, a wire such as Au. In this embodiment, wire bonding is illustrated, but for example, FPC (Flexible Printed Circuits) or the like may be used.
Further, the pedestal portion 621 has a through hole 625 formed at a position where the inner terminal portion 624 is provided. The inner terminal portion 624 is connected to the outer terminal portion 626 provided on the base outer surface 621B of the pedestal portion 621 via the through hole 625.

The side wall portion 622 rises from the edge portion of the pedestal portion 621, and the surface (end surface 622A) of the side wall portion 622 provided surrounding the periphery of the base inner side surface 621A is parallel to or substantially equal to, for example, the base inner side surface 621A. It becomes a parallel flat surface.

Then, the wavelength tunable interference filter 5 is fixed to the base 620 by using a fixing material 64 such as an adhesive. At this time, the tunable interference filter 5 may be fixed to the pedestal portion 621 or may be fixed to the side wall portion 622. The fixing material 64 may be provided at a plurality of positions, but the wavelength tunable interference filter 5 is fixed at one place in order to suppress the stress of the fixing material 64 from being transmitted to the wavelength tunable interference filter 5. Is preferable.

(Lid configuration)
The lid 630 is a transparent member having a rectangular outer shape in a plan view, and is made of, for example, glass or the like.
The lid 630 is joined to the side wall portion 622 of the base 620, as shown in FIG. Examples of this joining method include joining using low melting point glass.

[Action and effect of the fourth embodiment]
In the optical filter device 600 of the present embodiment as described above, since the wavelength tunable interference filter 5 is protected by the housing 610, damage to the wavelength tunable interference filter 5 due to an external factor can be prevented.
Further, as described above, the wavelength variable interference filter 5 first connects the electric charges of the metal films 542 and 552 which are the conductive layers even when the first reflective film 54 and the second reflective film 55 are charged. It can escape from the electrode 565. That is, in the optical filter device 600, the outer terminal portion 626 conductive to the first connection electrode 565 is connected to a circuit such as a ground circuit to which a reference potential is applied, or is connected to a metal case or the like in an electronic device. As a result, the charging of the first reflective film 54 and the second reflective film 55 of the variable wavelength interference filter 5 can be easily suppressed.

[Fifth Embodiment]
Next, as a fifth embodiment, as an example of an electronic device including the wavelength tunable interference filters 5, 5A, 5B of the first to third embodiments or the optical filter device 600 of the fourth embodiment, a printing apparatus. (Printer) will be described.

[Outline configuration of printer]
FIG. 14 is a diagram showing a configuration example of the appearance of the printer 10 of the fourth embodiment. FIG. 15 is a block diagram showing a schematic configuration of the printer 10 of the present embodiment.
As shown in FIG. 14, the printer 10 includes a supply unit 11, a transport unit 12, a carriage 13, a carriage moving unit 14, and a control unit 15 (see FIG. 15). The printer 10 controls each unit 11, 12, 14 and a carriage 13 based on print data input from an external device 20 such as a personal computer, and prints an image on the medium A. Further, the printer 10 of the present embodiment forms a color patch for color measurement at a predetermined position on the medium A based on preset calibration print data, and performs spectroscopic measurement on the color patch. As a result, the printer 10 compares the measured value for the color patch with the print data for calibration to determine whether or not the printed color has a color shift, and if there is a color shift, the printer 10 is based on the measured value. To perform color correction.
Hereinafter, each configuration of the printer 10 will be specifically described.

The supply unit 11 is a unit that supplies the medium A to be image-formed to the image-forming position. The supply unit 11 includes, for example, a roll body 111 (see FIG. 14) around which the medium A is wound, a roll drive motor (not shown), a roll drive train wheel (not shown), and the like. Then, based on the command from the control unit 15, the roll drive motor is rotationally driven, and the rotational force of the roll drive motor is transmitted to the roll body 111 via the roll drive train wheel train. As a result, the roll body 111 rotates, and the paper surface wound around the roll body 111 is supplied to the downstream side (+ Y direction) in the Y direction (sub-scanning direction).
In this embodiment, an example of supplying the paper surface wound around the roll body 111 is shown, but the present invention is not limited to this. For example, the medium A may be supplied by any supply method, for example, the medium A such as a paper surface loaded on a tray or the like is supplied one by one by a roller or the like.

The transport unit 12 transports the medium A supplied from the supply unit 11 along the Y direction. The transport unit 12 includes a transport roller 121, a driven roller (not shown) that is arranged with the transport roller 121 and the medium A interposed therebetween and is driven by the transport roller 121, and a platen 122.
When the drive force from the transfer motor (not shown) is transmitted to the transfer roller 121 and the transfer motor is driven by the control of the control unit 15, the transfer roller 121 is rotationally driven by the rotational force to move the medium A between the transfer roller 121 and the driven roller. It is conveyed along the Y direction while being sandwiched. Further, a platen 122 facing the carriage 13 is provided on the downstream side (+ Y side) of the transport roller 121 in the Y direction.

The carriage 13 includes a printing unit 16 that prints an image on the medium A, and a spectroscope 17 that performs spectroscopic measurement of a predetermined measurement position T (see FIG. 13) on the medium A.
The carriage 13 is provided by the carriage moving unit 14 so as to be movable along the main scanning direction intersecting the Y direction.
Further, the carriage 13 is connected to the control unit 15 by the flexible circuit 131, and print processing by the printing unit 16 and spectroscopic measurement processing by the spectroscope 17 are performed based on the command from the control unit 15.
The detailed configuration of the carriage 13 will be described later.

The carriage moving unit 14 constitutes the moving mechanism in the present invention, and moves the carriage 13 back and forth along the X direction based on a command from the control unit 15.
The carriage moving unit 14 includes, for example, a carriage guide shaft 141, a carriage motor 142, and a timing belt 143.
The carriage guide shaft 141 is arranged along the X direction, and both ends thereof are fixed to, for example, a housing of the printer 10. The carriage motor 142 drives the timing belt 143. The timing belt 143 is supported substantially parallel to the carriage guide shaft 141, and a part of the carriage 13 is fixed. Then, when the carriage motor 142 is driven based on the command of the control unit 15, the timing belt 143 travels forward and reverse, and the carriage 13 fixed to the timing belt 143 is guided by the carriage guide shaft 141 and reciprocates.

Next, the configurations of the printing unit 16 and the spectroscope 17 provided on the carriage 13 will be described with reference to the drawings.
[Structure of printing unit 16]
The printing unit 16 individually ejects ink onto the medium A at a portion facing the medium A to form an image on the medium A.
Ink cartridges 161 corresponding to inks of a plurality of colors are detachably mounted on the printing unit 16, and ink is supplied from each ink cartridge 161 to an ink tank (not shown) via a tube (not shown). .. Further, on the lower surface of the printing unit 16 (position facing the medium A), nozzles (not shown) for ejecting ink droplets are provided corresponding to each color. For example, a piezo element is arranged in these nozzles, and by driving the piezo element, ink droplets supplied from the ink tank are ejected and land on the medium A to form dots.

[Spectroscope configuration]
FIG. 16 is a diagram showing a schematic configuration of the spectroscope 17.
The spectroscope 17 is an optical module according to the present invention, and as shown in FIG. 16, includes a light source unit 171, an optical filter device 600, a light receiving unit 173, a light guide unit 174, and a circuit unit 175. ..
The spectroscope 17 irradiates the measurement position T on the medium A with the illumination light from the light source unit 171 and causes the light component reflected at the measurement position T to enter the optical filter device 600 by the light guide unit 174. Then, the optical filter device 600 has the configuration of the third embodiment, emits (transmits) light having a predetermined wavelength from the reflected light, and receives the light by the light receiving unit 173. Further, the optical filter device 600 can select a transmission wavelength based on the control of the control unit 15, and by measuring the amount of light of each wavelength in visible light, spectroscopic measurement of the measurement position T on the medium A Is possible.

[Structure of light source unit]
The light source unit 171 includes a light source 171A and a light collecting unit 171B. The light source unit 171 irradiates the light emitted from the light source 171A into the measurement position T of the medium A from the normal direction with respect to the surface of the medium A.
As the light source 171A, a light source capable of emitting light of each wavelength in the visible light region is preferable. Examples of such a light source 171A include a halogen lamp, a xenon lamp, and a white LED. In particular, a white LED that can be easily installed in a limited space in the carriage 13 is preferable. The condensing unit 171B is composed of, for example, a condensing lens or the like, and condenses the light from the light source 171A at the measurement position T. In FIG. 16, the condensing unit 171B displays only one lens (condensing lens), but may be configured by combining a plurality of lenses.

[Structure of light receiving part and light guide optical system]
The light receiving unit 173 is arranged on the optical axis of the tunable interference filter 5 and receives the light transmitted through the tunable interference filter 5. Then, the light receiving unit 173 outputs a detection signal (current value) according to the amount of light received, based on the control of the control unit 15. The detection signal output by the light receiving unit 173 is input to the control unit 15 via an IV converter (not shown), an amplifier (not shown), and an AD converter (not shown).
The light guide unit 174 includes a reflector 174A and a bandpass filter 174B.
The light guide unit 174 reflects the light reflected at 45 ° with respect to the surface of the medium A at the measurement position T on the optical axis of the tunable interference filter 5 by the reflecting mirror 174A. The bandpass filter 174B transmits light in the visible light region (for example, 380 nm to 720 nm) and cuts ultraviolet light and infrared light. As a result, the light in the visible light region is incident on the wavelength variable interference filter 5, and the light receiving unit 173 receives the light having the wavelength selected by the wavelength variable interference filter 5 in the visible light region.

The circuit unit 175 is a circuit that is electrically connected to the control unit 15 and drives the tunable interference filter 5 based on a command from the control unit 15.
Specifically, the circuit unit 175 sets the mirror gap G as the target wavelength between the first electrode 561 connected to the first connection electrode 565 and the second electrode 562 connected to the second extraction electrode 564. A drive circuit 175A for applying a drive voltage for changing the gap size according to the gap size is provided. Here, in the present embodiment, the drive circuit 175A has a ground circuit 175B, and the first connection electrode 565 is electrically connected to the ground circuit 175B. As a result, the reference potential is applied to the first connection electrode 565, and the electric charges of the metal films 542 and 552 of the first reflection film 54 and the second reflection film 55 can be released.
The circuit unit 175 may be provided with a circuit other than the drive circuit 175A. For example, when a capacitance detection electrode for detecting the capacitance of the mirror gap G is provided in the mirror region M, a capacitance detection circuit for detecting the capacitance between the capacitance detection electrodes may be provided. Further, a feedback circuit or the like that feedback-controls the drive voltage applied from the drive circuit 175A based on the capacitance detected by the capacitance detection circuit may be provided.

[Control unit configuration]
The control unit 15 is a control unit of the present invention, and as shown in FIG. 15, includes an I / F 151, a unit control circuit 152, a memory 153, and a CPU (Central Processing Unit) 154. There is.
The I / F 151 inputs the print data input from the external device 20 to the CPU 154.
The unit control circuit 152 includes a control circuit for controlling the supply unit 11, the transfer unit 12, the printing unit 16, the light source 171A, the tunable interference filter 5, the light receiving unit 173, and the carriage moving unit 14, respectively, from the CPU 154. The operation of each unit is controlled based on the command signal. The control circuit of each unit may be provided separately from the control unit 15 and connected to the control unit 15.

The memory 153 stores various programs and various data that control the operation of the printer 10.
Various data include, for example, V-λ data showing the wavelength of light transmitted through the wavelength variable interference filter 5 with respect to the voltage applied to the electrostatic actuator 56 when controlling the wavelength variable interference filter 5, and print data. Examples thereof include print profile data in which the ejection amount of each ink with respect to the included color data is stored. Further, the light emitting characteristic (light emitting spectrum) for each wavelength of the light source 171A, the light receiving characteristic (light receiving sensitivity characteristic) for each wavelength of the light receiving unit 173, and the like may be stored.

The CPU 154 reads and executes various programs stored in the memory 153 to drive control of the units 11, 12, and 14, print control of the printing unit 16, and measurement control by the spectroscope 17 (static of the wavelength variable interference filter 5). (Drive control of the electric actuator 56, etc.), color measurement processing based on the spectroscopic measurement result of the spectroscope 17, correction (update) processing of print profile data, and the like.

[Action and effect of the fifth embodiment]
The printer 10 of the present embodiment includes a spectroscope 17 which is an optical module, and the spectroscope 17 includes an optical filter device 600 (tunable interference filter 5) and a circuit unit 175 for driving the tunable interference filter 5. I have. Further, the circuit unit 175 is provided with a ground circuit 175B that applies a reference potential to the first connection electrode 565.
Therefore, the electric charge accumulated in the first reflective film 54 and the second reflective film 55 of the wavelength variable interference filter 5 can be released from the first connection electrode 565 to the ground circuit 175B, and the influence of the electric charge in the wavelength variable interference filter 5 can be released. Can be suppressed. Therefore, it is not necessary to incorporate a circuit that performs complicated drive control in consideration of the charging of the first reflective film 54 and the second reflective film 55 as the circuit unit 175 that drives the wavelength variable interference filter 5, and the configuration is simplified. Therefore, the cost of the spectroscope 17 can be reduced, and therefore the cost of the electronic device can be reduced.

[Modification example]
The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the range in which the object of the present invention can be achieved are included in the present invention.

[Modification 1]
In the above-described first embodiment, as the shape of the first through hole 543 and the second through hole 553, a configuration in which each layer has a stepped shape is illustrated, but the shape is not limited to this.
17 to 20 are views showing another example of the first through hole. Although an example of the first through hole provided in the first reflective film 54 is shown in FIGS. 17 to 20, the same applies to the second through hole formed in the second reflective film 55, which is shown here. And the description will be omitted.

For example, as shown in FIG. 17, the first through hole 544A is a hole having an inner peripheral surface of the hole that is substantially parallel to the stacking direction of the oxide film 541 and the metal film 542 constituting the first reflection film 54. It may be. Such a first through hole 544A can be formed by dry etching, for example, by ion milling or the like. Further, in such dry etching, it is not necessary to individually perform wet etching on each layer constituting the first reflective film 54, so that the manufacturing efficiency can be further improved.

Further, in the example shown in FIG. 18, the first through hole 544B is formed in a (inner peripheral conical) shape having an inclined surface that expands as the distance from the first substrate 51 increases. In the example shown in FIG. 17, the side surfaces of each oxide film 541 and each metal film 542 exposed to the first through hole 544A are substantially parallel to the stacking direction. In this case, it is difficult to form the first extraction electrode 563 on the side surface of each oxide film 541 and each metal film 542, and there is a risk of disconnection. On the other hand, in the first through hole 544B shown in FIG. 18, the surface of each oxide film 541 and each metal film 542 exposed to the first through hole 544B is an inclined surface, so that the first extraction electrode 563 is formed. It is easy to do, and disconnection is unlikely to occur.
Even in the first through hole 544A shown in FIG. 17, disconnection can be suppressed by filling (filling) the inside of the hole with the electrode material of the first lead electrode 563.

Further, in the first through hole 544C shown in FIG. 19, the hole diameter L2 of the second through hole 542A formed in the metal film 542 is directly above the metal film 542 (first substrate 51) in substantially the same manner as in the first embodiment. It is formed to be smaller than the pore diameter L1 of the first through hole 541A formed in the oxide film 541 adjacent to the oxide film 541 (on the side away from the). On the other hand, the first through hole 541A of the oxide film 541 adjacent immediately below the metal film 542 (the side close to the first substrate 51) has the same pore diameter L1 as the second through hole 542A of the metal film 542 directly above. ..
In such a configuration, as in the first embodiment, a part of the upper surface (the surface facing the second substrate 52) of each metal film 542 is exposed in the first through hole 544C, so that the first is preferable. The extraction electrode 563 and the metal film 542 can be connected.

Further, in the formation of the first through hole 543, an example in which the formation of the resist pattern and the wet etching are repeatedly performed a plurality of times is shown, but the present invention is not limited to this.
For example, a resist having an opening having a hole diameter corresponding to the bottom surface 543B of the first through hole 543 is formed on the oxide film 541 located on the outermost surface. After that, the outermost oxide film 541 is wet-etched using the metal film 542 directly below as an etching stopper. After that, the metal film 542 directly under the oxide film 541 on the outermost surface is wet-etched using the oxide film 541 directly under the metal film 542 as an etching stopper. After that, the second oxide film 541 from the outermost surface is wet-etched again. At this time, the oxide film 541 on the outermost surface is side-etched, so that a part of the upper surface of the metal film 542 located immediately below the outermost surface is exposed in the first through hole 543. By repeating the above process, a stepped first through hole 543 may be formed at each layer position.

Further, in each of the above embodiments and the examples shown in FIGS. 17 to 19, the first through hole 543 penetrates the first reflective film 54, and the first substrate 51 is the bottom surface 543B of the first through hole 543. , Not limited to this. For example, as shown in FIG. 20, it is sufficient that the first through hole 544D in which the metal film 542, which is at least one conductive layer of the first reflective film 54, is exposed is formed. That is, when the charge of the metal film 542 located at the position farthest from the first substrate 51 among the metal films 542 is removed, polarization in each layer arranged on the first substrate 51 side of the metal film 542 or Charging can be effectively suppressed.
Further, as shown in FIG. 20, in the configuration in which the first through hole 541A is provided only in the oxide film 541 arranged on the surface, wet etching may be performed only once when the first through hole 544D is formed, and the manufacturing efficiency is high. Is improved. Further, since the upper surface of the metal film 542 immediately below the outermost oxide film 541 is exposed on the first through hole 544D, disconnection between the first extraction electrode 563 and the metal film 542 is suppressed, and the electric charge of the metal film 542 is suppressed. Can be released more appropriately.

[Modification 2]
In each of the above embodiments, the positions of the first through hole 543 and the second through hole 553 are not limited to the positions overlapping the drawer groove 511A in a plan view.
For example, the electrode arrangement groove 511 may be formed as the formation position of the first through hole 543. Further, although the first lead-out electrode 563 is illustrated as the first wiring electrode of the present invention, when the first through hole 543 is provided in the electrode arrangement groove 511 as described above, the first electrode 561 is connected to the first through hole 543. It may be the first wiring electrode to be used. The second through hole 553 may be provided in, for example, an electrical component unit 560 or the like.
Further, when the first extraction electrode 563 and the first connection electrode 565 are connected in a part of the first joint portion 513 as in the first embodiment, the first through hole 543 or the second through hole 543 or the second through hole 543 or the second through hole 543 or the second Through holes 553 may be provided.
That is, the first through hole 543 and the second through hole 553 may be formed at any position as long as they are in regions other than the mirror region M.

Further, in each of the above embodiments, one first through hole 543 and one second through hole 553 are provided, but the present invention is not limited to this. For example, a plurality of first through holes 543 and a plurality of second through holes 553 may be provided. In this case, at least one or more of the plurality of first through holes 543 may be connected to the first extraction electrode 563 or the first electrode 561. Further, at least one or more of the plurality of second through holes 553 may be connected to the first connection electrode 565.

[Modification 3]
In each of the above embodiments, the first electrode 561 and the second electrode 562 that form the electrostatic actuator 56 are provided in the tunable interference filter 5, but other electrodes may be further provided.
For example, an electrode (mirror electrode) for detecting capacitance may be formed on the mirror region M of the first reflective film 54 and the second reflective film 55. In this case, it is necessary to form an extraction electrode for inputting / outputting a signal to the mirror electrode. Here, when the reflective film is provided only in the mirror region M by using lift-off or the like, a step may occur between the side surface of the reflective film and the first substrate 51 (or the second substrate 52) and the lead electrode may be disconnected. There is. On the other hand, in the configuration in which the reflective film formed of the dielectric multilayer film is provided on substantially the entire surface of the substrate (first substrate 51 or second substrate 52) as in the present embodiment, the reflective film is formed. It is not necessary to form an electrode on the side surface, and disconnection of the electrode can be suppressed.

Further, as described above, in the configuration in which the mirror electrodes for capacitance detection are provided in both the mirror regions M of the first substrate 51 and the second substrate 52, the potential of either one of these mirror electrodes is set as the reference potential ( For example, it may be 0V). In such a case, the mirror lead electrode connected to the mirror electrode set to the reference potential may be used as the first wiring electrode (or the second wiring electrode) connected to the through hole.
For example, when the first mirror electrode is arranged in the mirror region M of the first substrate 51 and the second mirror electrode is arranged in the mirror region M of the second substrate 52, the first extraction electrode connected to the first mirror electrode A part is connected to the first through hole 543. Further, in the second substrate 52, a second wiring electrode (independent) connected to the second through hole 553 and not connected to the second mirror electrode, the second electrode 562, or the second extraction electrode 564 is arranged, and the second wiring electrode is arranged. The wiring electrode is extended to the electrical component. Then, the first mirror extraction electrode and the second wiring electrode are brought into contact with each other as in the first embodiment or bump-connected as in the second embodiment to make them conductive.

Further, the mirror electrode may function as an electrode for removing static electricity instead of an electrode for detecting capacitance. In this case, for example, the first mirror extraction electrode connected to the first mirror electrode is connected to the first through hole 543. Further, the second mirror extraction electrode connected to the second mirror electrode is connected to the second through hole 553. Then, these first mirror extraction electrodes and the second mirror extraction electrodes are connected, and the second mirror extraction electrodes are extended to the electrical component portion 560.
With such a configuration, the electric charges accumulated in the metal films 542 and 552 of the first reflective film 54 and the second reflective film 55 and each mirror electrode can be released, and the first reflective film 54 and the first reflective film 54 and the second reflective film can be released. The electrostatic charge of the two reflective films 55 can be suitably removed.

[Modification example 4]
In the second embodiment, the configuration in which the first extraction electrode 563 of the protrusion tip surface 514A of the protrusion 514 is connected to the first connection electrode 565 arranged on the bottom surface 553B of the second through hole 553 is illustrated. On the other hand, for example, the first extraction electrode 563 formed on the side surface continuous with the protruding tip surface 514A of the protruding portion 514 is formed on the inner peripheral surface 553A of the second through hole 553, and the first connecting electrode 565 is formed. It may be made conductive by contacting with.

[Modification 5]
In the second embodiment, the protrusion 514 integrally formed with the first substrate 51 has been illustrated. Such a protruding portion 514 can be formed at the same time when the shape of the first substrate 51 is formed by etching. On the other hand, the first substrate 51 and the protruding portion 514 may be separate bodies.
The example shown in FIG. 21 is a cross-sectional view showing another example of the connection configuration of the first extraction electrode and the first connection electrode in the second embodiment.
In the example shown in FIG. 21, a protruding portion 515 made of, for example, an elastic member such as a resin is provided on the first substrate 51, and the first extraction electrode 563 is formed so as to cover the protruding portion 515.
In this case, when the first substrate 51 and the second substrate 52 are joined, the protruding portion 515 is elastically deformed, so that the first extraction electrode 563 can be pressed toward the first connection electrode 565. Therefore, the first lead-out electrode 563 and the first connection electrode 565 can be reliably conducted with each other, and the wiring reliability is improved.
Further, in the second embodiment, the second substrate 52 may be tilted by being pushed away from the first substrate 51 by the protruding portion 515. Therefore, the total dimension of the protruding dimension of the protruding portion 514, the thickness dimension of the first drawer electrode 563, and the thickness dimension of the first connection electrode 565 is the depth dimension of the drawer groove 511A and the thickness dimension of the bonding film 53. It is necessary to accurately control the thickness dimension of each part of the wavelength variable interference filter 5A so as to be the total of. On the other hand, in the example of FIG. 21, the protrusion 515, which is an elastic member, is elastically deformed, so that the inclination of the second substrate 52 by the protrusion 515 can be suppressed.

The configuration for enhancing wiring reliability is not limited to the example of FIG. 21. FIG. 22 is a cross-sectional view showing still another example of the connection configuration of the first extraction electrode and the first connection electrode in the second embodiment.
In the example shown in FIG. 22, the projecting portion 514 is integrally provided on the first substrate 51 as in the second embodiment. A recess (diaphragm portion 524) is formed at a position where the protrusion 514 is formed on the surface of the second substrate 52 opposite to the first substrate 51. In such a configuration, when the first extraction electrode 563 is pressed against the first connection electrode 565 by the protrusion 514, the diaphragm portion 524 is displaced, so that the first extraction electrode 563 and the first connection electrode 565 Can be reliably conducted, and the inclination of the second substrate 52 due to the protruding portion 514 can be suppressed. Although FIG. 22 shows an example in which the diaphragm portion 524 is provided on the second substrate 52, the diaphragm portion 51 may be provided on the first substrate 51.

Further, in the second embodiment, the configuration in which the projecting portion 514 is provided on the first substrate 51 is illustrated, but the configuration may be such that the projecting portion is provided on the second substrate 52 and inserted into the first through hole 543. The protruding portion of the present invention may be integrally configured with the second substrate 52. In this case, as the projecting portion, a protrusion made of an elastic member may be used as shown in FIG. Further, as shown in FIG. 22, the diaphragm portion may be provided.
Further, the protrusions may be provided on both the first substrate 51 and the second substrate 52, and the protrusions may be brought into contact with each other to connect the electrodes provided at the contact positions.

[Modification 6]
In the above embodiment, the first through hole 543 is provided in the first reflective film 54, and the second through hole 553 is provided in the second reflective film 55, but only one of them may be used. Even in this case, the influence of charging can be reduced as compared with a configuration in which through holes are not provided on both sides and charging is not suppressed.

[Modification 7]
In the above embodiment, the first electrode 561 is used as a reference potential and the driving potential is applied to the second electrode 562, but the second electrode 562 is used as the reference potential and the driving potential is applied to the first electrode 561. May be good. In this case, a first wiring electrode independent (not connected) from the first extraction electrode 563 is separately formed on the first reflection film 54 and connected to each metal film 542 of the first through hole 543. Further, in the second substrate 52, the second extraction electrode 564 or the second electrode 562 is connected to the second through hole 553 and connected to each metal film 552 of the first through hole 543. Then, for example, the first wiring electrode and the second extraction electrode 564 are connected by using contact between the electrodes as in the first embodiment or bump connection as in the second embodiment.

[Modification 8]
In the above embodiment, the first connection electrode 565 is provided on the second substrate 52 in order to conduct the first extraction electrode 563 of the first substrate 51 to the electrical component 560 of the second substrate 52. Each of the second substrates 52 may be provided with an electrical component for connecting to the outside. In this case, the first lead-out electrode 563 connected to the first through hole 543 is extended to the electrical component of the first substrate 51, and the electrode (second wiring electrode) connected to the second through hole 553 is connected to the second substrate. It may be extended to 52 electrical parts.

[Modification 9]
Although the configuration of the optical filter device 600 has been illustrated in the fourth embodiment, the optical filter device 600 is not limited to the shape of the fourth embodiment. For example, the wavelength tunable interference filter 5 may be held inside the cylinder of the tubular housing.
Further, in the fifth embodiment, the printer 10 has been illustrated as an example of the electronic device, but the present invention is not limited to this. Examples of the electronic device provided with the wavelength variable interference filter 5 include a light source device that outputs light of a desired wavelength (for example, a laser light source device), a spectroscopic analyzer that analyzes the components contained in the object to be measured, and the like. Often, these light source devices and analyzers may be mounted on a wearable device or the like.

In addition, the specific structure for carrying out the present invention can be appropriately changed to another structure or the like within the range in which the object of the present invention can be achieved.

5,5A, 5B ... Variable wavelength interference filter, 10 ... Printer (electronic device), 15 ... Control unit (control unit), 17 ... Spectrometer (optical module), 51 ... First substrate, 52 ... Second substrate, 53 ... Bonding film, 54 ... First reflective film, 55 ... Second reflective film, 56 ... Electrostatic actuator, 514,515 ... Protruding part, 514A ... Protruding tip surface, 521 ... Movable part, 522 ... Holding part, 523 ... Substrate Outer peripheral portion 524 ... Diaphragm portion, 541 ... Oxide film (metal oxide film; insulating layer), 541A ... First through hole, 542 ... Metal film (conductive layer), 542A ... Second through hole, 543,544A, 544B, 544C, 544D ... 1st through hole, 543A ... Hole inner peripheral surface, 543B ... Bottom surface, 551 ... Oxide film (metal oxide film; insulating layer), 552 ... Metal film (conductive layer), 353 ... Second through hole, 353A ... Inner peripheral surface of the hole, 535B ... Bottom surface, 561 ... First electrode, 562 ... Second electrode, 563 ... First extraction electrode (first wiring electrode), 563A ... Electrode connection part, 564 ... Second extraction electrode, 565 ... First connection electrode (second wiring electrode), 565A ... Electrode connection, 600 ... Optical filter device, 610 ... Housing, G ... Mirror gap, L1 ... First through hole hole diameter, L2 ... Second through hole hole diameter , M ... Mirror area, N ... Outer area.

Claims (10)

With the first board
The first reflective film provided over one surface of the first substrate and
In a plan view of the first substrate viewed from the thickness direction, a second reflective film that overlaps the first reflective film at least in a predetermined mirror region and is arranged with respect to the first reflective film through a gap.
The first wiring electrode provided on the first reflective film is provided.
The first reflective film is a laminated body in which insulating layers and conductive layers are alternately laminated, and a part of the first reflective film is provided in the stacking direction of the insulating layer and the conductive layer, and at least. A first through hole is provided to expose one of the conductive layers.
An interference filter characterized in that the first wiring electrode is connected to the first through hole and conducts to the conductive layer exposed from the first through hole. In the interference filter according to claim 1,
The first through hole is a first through hole provided in the insulating layer and a second through hole provided in the conductive layer in contact with the first substrate side of the insulating layer and communicating with the first through hole. Including and
An interference filter characterized in that the second through hole is located inside the first through hole in the plan view. In the interference filter according to claim 1 or 2.
A second substrate facing the first substrate is provided.
The second reflective film is a laminated body provided over a surface of the second substrate facing the first substrate and in which an insulating layer and a conductive layer are laminated, and is a part of the second reflective film. Is provided along the stacking direction of the insulating layer and the conductive layer, and is provided with a second through hole in which at least one of the conductive layers is exposed.
An interference filter characterized in that a second wiring electrode connected to the second through hole and conducting to the conductive layer exposed from the second through hole is provided on the second reflective film. In the interference filter according to claim 3,
In the plan view, a protruding portion that protrudes from the first substrate toward the second substrate and is inserted into the second through hole is provided at a position that overlaps with the second through hole.
The first wiring electrode is provided from above the first reflective film to the protruding tip surface of the protruding portion.
A part of the second wiring electrode is extended to the second bottom surface of the second through hole facing the first substrate and is in contact with the first wiring electrode provided on the protruding tip surface. Interference filter. In the interference filter according to claim 4,
The interference filter is characterized in that the protruding portion projects from the first bottom surface of the first through hole facing the second substrate toward the second substrate. The interference filter according to any one of claims 1 to 5.
An interference filter characterized in that particles having an electric resistance value smaller than the electric resistance value of the conductive layer are doped in a region other than the mirror region of the conductive layer. The interference filter according to any one of claims 1 to 6,
A housing for storing the interference filter and
An optical filter device characterized by comprising. The interference filter according to any one of claims 1 to 6,
The circuit unit that drives the interference filter and
An optical module characterized by being equipped with. In the optical module according to claim 8.
The circuit unit is an optical module having a ground circuit having the first wiring electrode as a predetermined reference potential. The interference filter according to any one of claims 1 to 6,
A control unit that controls the interference filter and
An electronic device characterized by being equipped with.

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