JP6713589B1 - Photo detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photodetector capable of sufficiently improving the temperature characteristic of a transmission wavelength in a Fabry-Perot interference filter and stabilizing the holding state of the Fabry-Perot interference filter on a support member. A photodetection device 1A includes a Fabry-Perot interference filter 10, a photodetector 3, a spacer 4, and an adhesive member 5 for adhering the interference filter 10 and the spacer 4 to each other. The adhesive member 5 is in contact with each of the side surface of the interference filter 10 and a part of the mounting surface of the spacer 4. The interference filter 10 further includes a substrate 14 that supports the first mirror 31 and the second mirror 41. The first mirror 31 is composed of a dielectric multilayer film laminated on the light incident side of the substrate 14, and the second mirror 41 is a dielectric laminated on the light incident side of the first mirror 31. It is composed of a multilayer film. The adhesive member 5 does not reach the dielectric multilayer film forming the second mirror 41. [Selection diagram] Figure 1

Description

The present invention relates to a photodetector including a Fabry-Perot interference filter having a first mirror and a second mirror whose distance is variable.

Patent Document 1 discloses an interference filter having a first reflection film and a second reflection film whose distances are variable, a substrate supporting the interference filter, and an adhesive layer interposed between the interference filter and the substrate. , An optical module comprising. In the optical module described in Patent Document 1, a gel-like resin is used for the adhesive layer in order to relieve the stress generated in the interference filter due to the difference in thermal expansion coefficient between the interference filter and the substrate.

JP 2012-173347 A

However, when fixing the Fabry-Perot interference filter having the first mirror and the second mirror whose distance is variable and the support member, it is necessary to control the distance between the first mirror and the second mirror with extremely high accuracy. Therefore, just by interposing an adhesive layer made of a gel-like resin between the Fabry-Perot interference filter and the supporting member, it is possible to sufficiently change the stress generated in the Fabry-Perot interference filter due to changes in the operating environment temperature. This cannot be suppressed, and as a result, the temperature characteristic of the transmission wavelength in the Fabry-Perot interference filter (the temperature characteristic of the wavelength of the light transmitted by the Fabry-Perot interference filter) may not be sufficiently improved. Further, if an adhesive layer made of a gel resin is used to fix the Fabry-Perot interference filter and the supporting member, the holding state of the Fabry-Perot interference filter on the supporting member may become unstable.

Therefore, the present invention provides a photodetector capable of sufficiently improving the temperature characteristics of the transmission wavelength in the Fabry-Perot interference filter and stabilizing the holding state of the Fabry-Perot interference filter on the support member. With the goal.

The photodetector of the present invention has a first mirror and a second mirror whose distances are variable, and Fabry-Perot interference having a light transmission region that transmits light according to the distance between the first mirror and the second mirror. A filter, a photodetector for detecting light transmitted through the light transmission region, a support member having a mounting surface on which a portion outside the light transmission region of the bottom surface of the Fabry-Perot interference filter is mounted, and Fabry-Perot interference An adhesive member for adhering the filter and the support member is provided, the elastic modulus of the adhesive member is smaller than the elastic modulus of the support member, and at least a part of the side surface of the Fabry-Perot interference filter has a part of the mounting surface. The adhesive member is located on the mounting surface so as to be disposed on the outside of the side surface, and the adhesive member is disposed at the corner formed by the side surface and a part of the mounting surface. Some are in contact with each.

In this photodetector, an adhesive member having an elastic modulus smaller than that of the supporting member is arranged at the side surface of the Fabry-Perot interference filter and at the corner formed by a part of the mounting surface of the supporting member. , The side surface of the Fabry-Perot interference filter and a part of the mounting surface of the support member. Thereby, for example, compared with the case where the adhesive member is only interposed between the bottom surface of the Fabry-Perot interference filter and the mounting surface of the support member, the coefficient of thermal expansion between the Fabry-Perot interference filter and the support member. The stress generated in the Fabry-Perot interference filter due to the difference of 1 can be sufficiently absorbed by the adhesive member. Further, for example, as compared with a case where an adhesive member is only interposed between the bottom surface of the Fabry-Perot interference filter and the mounting surface of the support member, the Fabry-Perot interference filter is supported more firmly on the support member in a stable state. Can be held at. Therefore, according to this photodetector, the temperature characteristic of the transmission wavelength in the Fabry-Perot interference filter can be sufficiently improved, and the holding state of the Fabry-Perot interference filter on the support member can be stabilized.

In the photodetector of the present invention, the adhesive member includes the first portion arranged at the corner and the second portion arranged between the mounting surface and the bottom surface, and the direction perpendicular to the mounting surface. The value obtained by subtracting the thickness of the second portion in the direction perpendicular to the mounting surface from the height of the first portion at may be larger than the thickness of the second portion. Thereby, the stress generated in the Fabry-Perot interference filter due to the difference in thermal expansion coefficient between the Fabry-Perot interference filter and the support member can be more sufficiently absorbed by the adhesive member.

In the photodetector of the present invention, the Fabry-Perot interference filter may further include a substrate that supports the first mirror and the second mirror, and the adhesive member arranged at the corner may be in contact with the substrate on the side surface. .. Thereby, the stress generated in the Fabry-Perot interference filter due to the difference in thermal expansion coefficient between the Fabry-Perot interference filter and the support member can be more sufficiently absorbed by the adhesive member. In addition, since the substrate supporting the first mirror and the second mirror is held from the outside by the adhesive member, the holding state of the Fabry-Perot interference filter can be made more stable.

In the photodetector of the present invention, the side surface includes the first side surface, and the adhesive member is provided on the corner formed by the first side surface so as to be continuous over the entire corner formed by the first side surface. It may be arranged and in contact with the first side surface. As a result, for example, due to the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter and the support member, compared to the case where a plurality of adhesive members are intermittently arranged in the corner formed by the first side surface. Thus, the stress generated in the Fabry-Perot interference filter can be uniformly absorbed by the adhesive member.

In the photodetector of the present invention, the side surface includes the second side surface and the third side surface facing each other with the light transmission region interposed therebetween, and the adhesive member is formed by the corner formed by the second side surface and the third side surface. It may be arranged in each of the formed corners and may be in contact with each of the second side surface and the third side surface. This allows the Fabry-Perot interference filter to be held on the support member in a more stable state.

In the photodetector of the present invention, the side surface includes a fourth side surface and a fifth side surface forming a corner portion, and the adhesive member has a corner portion formed by the fourth side surface and a corner portion formed by the fifth side surface. And may be in contact with each of the fourth side surface and the fifth side surface. This allows the adhesive member to sufficiently absorb the stress at the corners where the stress generated in the Fabry-Perot interference filter due to the difference in thermal expansion coefficient between the Fabry-Perot interference filter and the support member is likely to concentrate. it can.

In the photodetector of the present invention, the adhesive member arranged at the corner formed by the fourth side surface and the adhesive member arranged at the corner formed by the fifth side surface may be continuous with each other. .. This allows the adhesive member to absorb the stress more sufficiently at the corners where the stress generated in the Fabry-Perot interference filter due to the difference in coefficient of thermal expansion between the Fabry-Perot interference filter and the support member is likely to concentrate. You can

ADVANTAGE OF THE INVENTION According to this invention, the temperature characteristic of the transmission wavelength in a Fabry-Perot interference filter can be fully improved, and the photodetector which can stabilize the holding state of a Fabry-Perot interference filter on a support member is provided. Is possible.

It is sectional drawing of the photon detection apparatus of 1st Embodiment. It is sectional drawing of the Fabry-Perot interference filter of the photon detection apparatus of FIG. FIG. 2 is a plan view of a portion including a Fabry-Perot interference filter, a spacer and an adhesive member in the photodetector of FIG. 1. It is sectional drawing of the part containing a Fabry-Perot interference filter, a spacer, and an adhesive member among the photodetectors of FIG. It is sectional drawing of the photon detection apparatus of 2nd Embodiment. FIG. 6 is a plan view of a portion including the Fabry-Perot interference filter, the third layer substrate, and the adhesive member in the photodetector in FIG. 5. It is sectional drawing of the modification of the photon detection apparatus of 2nd Embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are designated by the same reference numerals, and overlapping parts are omitted.
[First Embodiment]
[Configuration of photodetector]

As shown in FIG. 1, the photodetector 1</b>A includes a wiring board 2, a photodetector 3, a plurality of spacers 4, a plurality of adhesive members 5, and a Fabry-Perot interference filter 10. The Fabry-Perot interference filter 10 has a first mirror 31 and a second mirror 41 whose distance is variable. The light detection device 1A is a spectroscopic sensor that can obtain a spectroscopic spectrum. That is, in the light detection device 1A, when light is incident on the light transmission region 11 of the Fabry-Perot interference filter 10 from the outside, a predetermined distance is determined according to the distance between the first mirror 31 and the second mirror 41 in the light transmission region 11. Light having a wavelength is selectively transmitted, and the light transmitted through the light transmission region 11 of the Fabry-Perot interference filter 10 is detected by the photodetector 3.

A photodetector 3 and a temperature compensating element (not shown) such as a thermistor are mounted on the wiring board 2. As the substrate material of the wiring board 2, for example, silicon, ceramics, quartz, glass, plastic, or the like can be used. The photodetector 3 has a light receiving portion 3 a that receives the light transmitted through the light transmission region 11 of the Fabry-Perot interference filter 10. The light transmitting region 11 and the light receiving portion 3a face each other in the direction A in which light passes through the light transmitting region 11. As the photodetector 3, for example, an infrared detector can be used. As the infrared detector, for example, a quantum type sensor using InGaAs or the like, a thermal type sensor using a thermopile, a bolometer, or the like can be used. When detecting light in each wavelength range of ultraviolet, visible, and near infrared, a silicon photodiode or the like can be used as the photodetector 3, for example. Further, the photodetector 3 may be provided with one light receiving portion 3a, or may be provided with a plurality of light receiving portions 3a in an array. Furthermore, a plurality of photodetectors 3 may be mounted on the wiring board 2.

The plurality of spacers 4 are fixed on the wiring board 2 by an adhesive member (not shown). The Fabry-Perot interference filter 10 is fixed on the plurality of spacers 4 by an adhesive member 5. The plurality of spacers 4 function as supporting members that support the Fabry-Perot interference filter 10 on the wiring board 2. The photodetector 3 is arranged in the space formed between the wiring substrate 2 and the Fabry-Perot interference filter 10 by the plurality of spacers 4. As a material of each spacer 4, for example, silicon, ceramic, quartz, glass, plastic, or the like can be used. In particular, the material of each spacer 4 has the same coefficient of thermal expansion as that of the material of the Fabry-Perot interference filter 10 in order to reduce the difference in coefficient of thermal expansion between the Fabry-Perot interference filter 10 and each spacer 4. Is preferred. The wiring board 2 and the spacer 4 may be integrally formed. Further, the Fabry-Perot interference filter 10 may be supported by one spacer 4 instead of the plurality of spacers 4.

The material of the adhesive member 5 for adhering the Fabry-Perot interference filter 10 and each spacer 4 is a flexible resin material (for example, a silicone-based, urethane-based, epoxy-based, acrylic-based, hybrid, or other resin material). And may be conductive or non-conductive). The resin material is preferably selected from materials having a Young's modulus of less than 1000 MPa, and more preferably selected from materials having a Young's modulus of less than 10 MPa. Further, as the resin material, it is preferable to select a material whose glass transition temperature is out of the operating environment temperature of the photodetector 1A. For example, if an adhesive containing a silicone-based resin material is used as the material of the adhesive member 5, the Young's modulus after curing is less than 10 MPa, and the glass transition temperature is the operating environment temperature (for example, about 5 to 40° C.). Which is lower than that of -50 to -40°C.

Here, the elastic modulus of the adhesive member 5 that bonds the Fabry-Perot interference filter 10 and each spacer 4 is smaller than the elastic modulus of the spacer 4. The elastic modulus of the adhesive member 5 that bonds the Fabry-Perot interference filter 10 and each spacer 4 is smaller than the elastic modulus of the adhesive member (not shown) that bonds the wiring board 2 and each spacer 4. For example, if an adhesive containing an epoxy resin material is used as the material of the adhesive member that adheres the wiring board 2 and each spacer 4, the Young's modulus after curing is 100 MPa or more. The Young's modulus of the spacer 4 is 100 GPa or more when it is made of silicon, 100 GPa or more when it is made of ceramic, 10 GPa or more (generally 70 to 80 GPa) when it is made of glass, and when it is made of plastic. Is 0.1 GPa or more. The elastic modulus is Young's modulus (longitudinal elastic modulus: relationship of strain to tensile/compressive stress), lateral elastic modulus (relationship of strain to shear stress), and bulk elastic modulus (pressure and volume strain under uniform compression). Relationship with) is a generic term. That is, the Young's modulus is a specific example of the elastic modulus.

The photodetector 1A further includes a CAN package 6. The CAN package 6 accommodates the wiring board 2, the photodetector 3, the temperature compensation element (not shown), the plurality of spacers 4, the plurality of adhesive members 5, and the Fabry-Perot interference filter 10 described above. The CAN package 6 has a stem 61 and a cap 62. An opening 62a is provided in the cap 62, and a plate-shaped light transmitting member 63 is fixed to the opening 62a from the inside. The light transmitting region 11 and the opening 62a face each other in the direction A. As the material of the light transmitting member 63, a material (for example, glass, silicon, germanium, etc.) corresponding to the measurement wavelength range of the photodetector 1A can be used. Further, a light reflection preventing layer may be formed on at least one of the front surface and the back surface of the light transmitting member 63. Further, as the light transmission member 63, a bandpass filter that transmits only light in the measurement wavelength range may be used.

The wiring board 2 is fixed to the stem 61. The electrode pads provided on the wiring board 2, the terminals of the photodetector 3, the terminals of the temperature compensating element, and the terminals 12 and 13 of the Fabry-Perot interference filter 10 are respectively the lead pins 9 penetrating the stem 61. Is electrically connected by a wire 8. As a result, it is possible to input/output an electric signal to/from each of the photodetector 3, the temperature compensating element, and the Fabry-Perot interference filter 10. In the photodetector 1A, since the spacer 4 is arranged immediately below the terminals 12 and 13 of the Fabry-Perot interference filter 10, wire bonding can be reliably performed.

In the photodetector 1A configured as described above, when light is incident on the light transmission region 11 of the Fabry-Perot interference filter 10 from the outside through the opening 62a and the light transmission member 63, the first mirror in the light transmission region 11 is detected. Light having a predetermined wavelength is selectively transmitted in accordance with the distance between 31 and the second mirror 41. The light transmitted through the first mirror 31 and the second mirror 41 is incident on the light receiving section 3 a of the photodetector 3 and detected by the photodetector 3. In the photodetector 1A, while changing the voltage applied to the Fabry-Perot interference filter 10 (that is, changing the distance between the first mirror 31 and the second mirror 41), the first mirror 31 and the second mirror 41 are A spectrum can be obtained by detecting the transmitted light with the photodetector 3.
[Structure of Fabry-Perot interference filter]

As shown in FIG. 2, the Fabry-Perot interference filter 10 includes a substrate 14. The antireflection layer 15, the first stacked body 30, the sacrificial layer 16, and the second stacked body 40 are stacked in this order on the surface 14a of the substrate 14 on the light incident side. A space (air gap) S is formed by the frame-shaped sacrificial layer 16 between the first stacked body 30 and the second stacked body 40. In the Fabry-Perot interference filter 10, light enters the second stacked body 40 from the opposite side of the substrate 14. Then, the light having the predetermined wavelength passes through the light transmission region 11 defined in the central portion of the Fabry-Perot interference filter 10.

The substrate 14 is made of, for example, silicon, quartz, glass or the like. When the substrate 14 is made of silicon, the antireflection layer 15 and the sacrificial layer 16 are made of, for example, silicon oxide. The thickness of the sacrificial layer 16 is preferably an integral multiple of 1/2 of the central transmission wavelength (that is, the central wavelength of the wavelength range that the Fabry-Perot interference filter 10 can transmit).

A portion of the first stacked body 30 corresponding to the light transmission region 11 functions as the first mirror 31. The first stacked body 30 is configured by alternately stacking a plurality of polysilicon layers and a plurality of silicon nitride layers. The optical thickness of each of the polysilicon layer and the silicon nitride layer forming the first mirror 31 is preferably an integral multiple of ¼ of the central transmission wavelength. A silicon oxide layer may be used instead of the silicon nitride layer.

A portion of the second stacked body 40 that corresponds to the light transmission region 11 functions as a second mirror 41 that faces the first mirror 31 via the space S. Like the first stacked body 30, the second stacked body 40 is configured by alternately stacking a plurality of polysilicon layers and a plurality of silicon nitride layers. The optical thickness of each of the polysilicon layer and the silicon nitride layer forming the second mirror 41 is preferably an integral multiple of 1/4 of the central transmission wavelength. A silicon oxide layer may be used instead of the silicon nitride layer.

In the portion corresponding to the void S in the second stacked body 40, a plurality of through holes 40b extending from the surface 40a of the second stacked body 40 to the void S are provided so as to be uniformly distributed. The plurality of through holes 40b are formed to the extent that the function of the second mirror 41 is not substantially affected. The inner diameter of each through hole 40b is 100 nm to 5 μm. The opening area of the plurality of through holes 40b occupies 0.01 to 10% of the area of the second mirror 41.

In the Fabry-Perot interference filter 10, the first mirror 31 and the second mirror 41 are supported by the substrate 14. The first mirror 31 is arranged on the light incident side of the substrate 14. The second mirror 41 is arranged on the light incident side of the first mirror 31 via the space S.

A first electrode 17 is formed on the first mirror 31 so as to surround the light transmission region 11. Further, the second electrode 18 is formed on the first mirror 31 so as to include the light transmission region 11. The first electrode 17 and the second electrode 18 are formed by doping the polysilicon layer with impurities to reduce the resistance. The size of the second electrode 18 is preferably a size including the entire light transmission region 11, but may be substantially the same as the size of the light transmission region 11.

The third electrode 19 is formed on the second mirror 41. The third electrode 19 faces the first electrode 17 and the second electrode 18 in the direction A with the space S in between. The third electrode 19 is formed by doping the polysilicon layer with impurities to reduce the resistance.

In the Fabry-Perot interference filter 10, the second electrode 18 is located on the opposite side of the third electrode 19 with respect to the first electrode 17 in the direction A. That is, the first electrode 17 and the second electrode 18 are not arranged on the same plane in the first mirror 31. The second electrode 18 is farther from the third electrode 19 than the first electrode 17.

The terminal 12 is for applying a voltage to the Fabry-Perot interference filter 10. A pair of terminals 12 are provided so as to face each other with the light transmission region 11 interposed therebetween. Each terminal 12 is arranged in a through hole extending from the surface 40 a of the second stacked body 40 to the first stacked body 30. Each terminal 12 is electrically connected to the first electrode 17 via the wiring 21.

The terminal 13 is for applying a voltage to the Fabry-Perot interference filter 10. A pair of terminals 13 are provided so as to face each other with the light transmission region 11 interposed therebetween. The direction in which the pair of terminals 12 face each other and the direction in which the pair of terminals 13 face each other are orthogonal to each other. Each terminal 13 is electrically connected to the third electrode 19 via the wiring 22. The third electrode 19 is also electrically connected to the second electrode 18 via the wiring 23.

Trenches 26 and 27 are provided on the surface 30 a of the first stacked body 30. The trench 26 extends annularly so as to surround the wiring 23 extending from the terminal 13 along the direction A. The trench 26 electrically insulates the first electrode 17 and the wiring 23 from each other. The trench 27 extends in a ring shape along the inner edge of the first electrode 17. The trench 27 electrically insulates the first electrode 17 and a region inside the first electrode 17. The regions within each trench 26, 27 may be insulating material or voids.

The trench 28 is provided on the surface 40 a of the second stacked body 40. The trench 28 extends annularly so as to surround the terminal 12. The bottom surface of the trench 28 reaches the sacrifice layer 16. The trench 28 electrically insulates the terminal 12 and the third electrode 19 from each other. The region within trench 28 may be an insulating material or a void.

An antireflection layer 51, a third stacked body 52, an intermediate layer 53, and a fourth stacked body 54 are stacked in this order on the surface 14b on the light emitting side of the substrate 14. The antireflection layer 51 and the intermediate layer 53 have the same configurations as the antireflection layer 15 and the sacrificial layer 16, respectively. The third stacked body 52 and the fourth stacked body 54 have a stacked structure that is symmetrical to the first stacked body 30 and the second stacked body 40 with respect to the substrate 14, respectively. The antireflection layer 51, the third laminated body 52, the intermediate layer 53, and the fourth laminated body 54 constitute a laminated body 50. The laminated body 50 is disposed on the light emitting side of the substrate 14 and has a function of suppressing the warp of the substrate 14.

In the laminated body 50, for example, a cylindrical opening 50a is formed so as to include the light transmission region 11. The opening 50a is opened on the light emitting side, and the bottom surface of the opening 50a reaches the antireflection layer 51. A light shielding layer 29a is formed on the surface 50b on the light emitting side of the laminated body 50. The light shielding layer 29a is made of aluminum or the like. A protective layer 29b is formed on the surface of the light shielding layer 29a and the inner surface of the opening 50a. The protective layer 29b is made of, for example, aluminum oxide. By setting the thickness of the protective layer 29b to 1 to 100 nm (preferably about 30 nm), the optical influence of the protective layer 29b can be ignored.

In the Fabry-Perot interference filter 10 configured as described above, when a voltage is applied between the first electrode 17 and the third electrode 19 via the terminals 12 and 13, an electrostatic force corresponding to the voltage is generated. It occurs between the first electrode 17 and the third electrode 19. The second mirror 41 is driven by the electrostatic force so as to be attracted to the first mirror 31 side fixed to the substrate 14. By this driving, the distance between the first mirror 31 and the second mirror 41 is adjusted. The wavelength of the light passing through the Fabry-Perot interference filter 10 depends on the distance between the first mirror 31 and the second mirror 41 in the light transmitting region 11. Therefore, by adjusting the voltage applied between the first electrode 17 and the third electrode 19, the wavelength of the transmitted light can be appropriately selected. At this time, the second electrode 18 has the same potential as the electrically connected third electrode 19. Therefore, the second electrode 18 functions as a compensation electrode for keeping the first mirror 31 and the second mirror 41 flat in the light transmission region 11.
[Structure of Adhesive Member for Bonding Fabry-Perot Interference Filter and Spacer]

The configuration of the adhesive member 5 will be described in more detail with reference to FIGS. 3 and 4. Note that the wire 8, the stem 61, etc. are omitted in FIG. 3, and the wiring board 2, the wire 8, the stem 61, etc. are omitted in FIG. 4.

As shown in FIG. 3, the Fabry-Perot interference filter 10 is supported by a pair of spacers 4A and 4B. On the mounting surface 4a of the one spacer 4A, a part of the bottom surface 101 of the Fabry-Perot interference filter 10 outside the light transmission region 11 and along the side surface 102a of the Fabry-Perot interference filter 10 is mounted. Has been done. On the mounting surface 4a of the other spacer 4B, a portion of the bottom surface 101 of the Fabry-Perot interference filter 10 outside the light transmission region 11 and along the side surface 102b of the Fabry-Perot interference filter 10 is mounted. Has been done. The Fabry-Perot interference filter 10 has a rectangular side surface 102 when viewed from the direction A. Among the side surfaces 102, the side surface (first side surface, second side surface) 102a and the side surface (first side surface, third side surface) 102b are opposed to each other with the light transmission region 11 interposed therebetween.

The side surface 102a is located on the mounting surface 4a of the spacer 4A so that a part of the mounting surface 4a of the spacer 4A is arranged outside the side surface 102a (outside the side surface 102 when viewed from the direction A). ing. As a result, the corner C1 is formed by the side surface 102a and the portion of the mounting surface 4a of the spacer 4A outside the side surface 102a (the exposed portion where the Fabry-Perot interference filter 10 is not mounted). ing. One end portion of the side surface (fifth side surface) 102c of the side surface 102 that forms the corner portion 103a together with the side surface (fourth side surface) 102a has a corner 103a side end part of the mounting surface 4a of the spacer 4A outside the side surface 102c. Is located on the mounting surface 4a of the spacer 4A. As a result, one end portion of the side surface 102c and a portion of the mounting surface 4a of the spacer 4A outside the one end portion of the side surface 102c (an exposed portion where the Fabry-Perot interference filter 10 is not mounted), A corner portion C2 is formed. One end of the side surface (fifth side surface) 102d of the side surface 102, which forms a corner portion 103b with the side surface (fourth side surface) 102a, is on the corner portion 103b side, and a part of the mounting surface 4a of the spacer 4A is outside the side surface 102d. Is located on the mounting surface 4a of the spacer 4A. As a result, one end of the side surface 102d and a portion of the mounting surface 4a of the spacer 4A outside the one end of the side surface 102d (a portion exposed without the Fabry-Perot interference filter 10 being mounted) A corner C3 is formed. Note that the side surfaces 102a, the one ends of the side surfaces 102c, and the one end of the side surfaces 102d correspond to a part of the outer edge of the Fabry-Perot interference filter 10 when viewed from the direction A.

The side surface 102b is located on the mounting surface 4a of the spacer 4B so that a part of the mounting surface 4a of the spacer 4B is arranged outside the side surface 102b. As a result, the corner C4 is formed by the side surface 102b and the portion of the mounting surface 4a of the spacer 4B outside the side surface 102b (the exposed portion without the Fabry-Perot interference filter 10 being mounted). ing. Among the side surfaces 102, the other end portion on the corner portion 103c side of the side surface (fifth side surface) 102c that forms the corner portion 103c together with the side surface (fourth side surface) 102b is such that a part of the mounting surface 4a of the spacer 4B is the side surface 102c. It is positioned on the mounting surface 4a of the spacer 4B so as to be arranged outside. As a result, the other end of the side surface 102c and a portion of the mounting surface 4a of the spacer 4B outside the other end of the side surface 102c (a portion exposed without the Fabry-Perot interference filter 10 being mounted). Thus, the corner C5 is formed. Among the side surfaces 102, the other end portion on the corner 103d side of the side surface (fifth side surface) 102d that forms the corner portion 103d together with the side surface (fourth side surface) 102b has a portion of the mounting surface 4a of the spacer 4B on the side surface 102d. It is positioned on the mounting surface 4a of the spacer 4B so as to be arranged outside. As a result, the other end of the side surface 102d and a portion of the mounting surface 4a of the spacer 4B outside the other end of the side surface 102d (a portion exposed without the Fabry-Perot interference filter 10 being mounted) are formed. Thus, the corner portion C6 is formed. The other ends of the side face 102b, the side face 102c, and the other end of the side face 102d correspond to part of the outer edge of the Fabry-Perot interference filter 10 when viewed from the direction A.

On the mounting surface 4a of the spacer 4A, the adhesive members 5 are arranged at the corners C1, C2, C3, and the adhesive members 5 arranged at the corners C1, C2, C3 are continuous with each other. .. That is, the adhesive member 5 arranged on the mounting surface 4a of the spacer 4A is continuous over the entire corner C1 and covers the corners 103a and 103b from the outside.

On the mounting surface 4a of the spacer 4B, the adhesive members 5 are arranged at the corners C4, C5, C6, and the adhesive members 5 arranged at the corners C4, C5, C6 are continuous with each other. .. That is, the adhesive member 5 arranged on the mounting surface 4a of the spacer 4B is continuous over the entire corner C4 and covers the corners 103c and 103d from the outside.

As shown in FIG. 4, the adhesive member 5 arranged on the mounting surface 4a of the spacer 4A includes a first portion 5a and a second portion 5b. The first portion 5a is a portion arranged along each corner C1, C2, C3, and is continuous via each corner 103a, 103b. The second portion 5b is a portion arranged between the mounting surface 4a of the spacer 4A and the bottom surface 101 of the Fabry-Perot interference filter 10. In the corner C1, the first portion 5a is in contact with each of the side surface 102a and the mounting surface 4a of the spacer 4A. At the corner C2, the first portion 5a is in contact with one end of the side surface 102c and the mounting surface 4a of the spacer 4A. In the corner C3, the first portion 5a is in contact with one end of the side surface 102d and the mounting surface 4a of the spacer 4A. That is, the adhesive member 5 arranged on the mounting surface 4a of the spacer 4A is in contact with each of the side surface 102 and the mounting surface 4a of the spacer 4A.

Similarly, the adhesive member 5 arranged on the mounting surface 4a of the spacer 4B includes a first portion 5a and a second portion 5b. The first portion 5a is a portion arranged along the corners C4, C5, C6, and is continuous via the corners 103c, 103d. The second portion 5b is a portion arranged between the mounting surface 4a of the spacer 4B and the bottom surface 101 of the Fabry-Perot interference filter 10. At the corner C4, the first portion 5a is in contact with each of the side surface 102b and the mounting surface 4a of the spacer 4B. At the corner C5, the first portion 5a is in contact with the other end of the side surface 102c and the mounting surface 4a of the spacer 4B. At the corner C6, the first portion 5a is in contact with the other end of the side surface 102d and the mounting surface 4a of the spacer 4B. That is, the adhesive member 5 arranged on the mounting surface 4a of the spacer 4B is in contact with each of the side surface 102 and the mounting surface 4a of the spacer 4B.

In each of the corners C1, C2, C3, the highest edge 5c of the first portion 5a reaches the side surface of the substrate 14 of the Fabry-Perot interference filter 10. That is, the adhesive member 5 arranged on the mounting surface 4a of the spacer 4A is in contact with the substrate 14 on the side surface 102. Similarly, in each of the corners C4, C5, C6, the highest edge 5c of the first portion 5a reaches the side surface of the substrate 14 of the Fabry-Perot interference filter 10. That is, the adhesive member 5 arranged on the mounting surface 4a of the spacer 4B is in contact with the substrate 14 on the side surface 102.

As an example, the height H of the first portion 5a in the direction perpendicular to the mounting surface 4a of each spacer 4A, 4B and the width W of the first portion 5a in the direction perpendicular to the side surface 102 of the Fabry-Perot interference filter 10 are: Each is 10 to 1000 μm. The Fabry-Perot interference filter 10 has a thickness of 100 to 1000 μm. The width (width in the direction perpendicular to the side surface 102) of the portion of the mounting surface 4a that projects to the outside of the side surface 102 is 10 to 1000 μm. Here, the height H of the first portion 5a is preferably 1/10 or more of the thickness of the Fabry-Perot interference filter 10 and less than the thickness of the Fabry-Perot interference filter 10. Further, in the Fabry-Perot interference filter 10, the distance between the bottom surface 101 and the surface 14b on the light emitting side of the substrate 14 is 0.1 to 10 μm, so that if the height H of the first portion 5a is 10 μm or more, The highest edge 5c of the one portion 5a can reach the side surface of the substrate 14 of the Fabry-Perot interference filter 10. Further, in the adhesive member 5, a value obtained by subtracting the thickness of the second portion 5b in the direction perpendicular to the mounting surface 4a from the height H of the first portion 5a in the direction perpendicular to the mounting surface 4a (Fabry-Perot interference). The height of the edge portion 5c from the bottom surface 101 of the filter 10) is larger than the thickness of the second portion 5b in the direction perpendicular to the mounting surface 4a.
[Action and effect]

In the photodetector 1A, the adhesive member 5 having an elastic modulus smaller than the elastic modulus of each spacer 4A, 4B is arranged in the corners C1, C2, C3, C4, C5, C6, and the Fabry-Perot interference filter The side surface 102 and a part of the mounting surface 4a of each of the spacers 4A and 4B are in contact with each other. Thereby, for example, as compared with the case where the adhesive member 5 is only interposed between the bottom surface 101 of the Fabry-Perot interference filter 10 and the mounting surface 4a of each of the spacers 4A and 4B, the Fabry-Perot interference filter 10 and the optical fiber are not provided. This occurs in the Fabry-Perot interference filter 10 due to the difference in the thermal expansion coefficient between the detection device 1A and other members (not only the spacers 4A and 4B, but also the wiring board 2, the stem 61, the cap 62, etc.). The stress can be sufficiently absorbed by the adhesive member 5. Further, for example, the Fabry-Perot interference filter 10 is stabilized compared to the case where the adhesive member 5 is only interposed between the bottom surface 101 of the Fabry-Perot interference filter 10 and the mounting surfaces 4a of the spacers 4A and 4B. In this state, it can be more firmly held on the spacers 4A and 4B. Therefore, according to the photodetector 1A, the temperature characteristics of the transmission wavelength in the Fabry-Perot interference filter 10 can be sufficiently improved, and the holding state of the Fabry-Perot interference filter 10 on the spacers 4A and 4B can be stabilized. it can. The adhesive member 5 is smaller than the elastic modulus of other members (not only the spacers 4A and 4B but also the Fabry-Perot interference filter 10, the wiring substrate 2, the stem 61, the cap 62, etc.) that configure the photodetector 1A. It preferably has an elastic modulus.

Here, the reason why the temperature characteristic of the transmission wavelength in the Fabry-Perot interference filter 10 is improved as the elastic modulus of the adhesive member 5 becomes smaller and the amount (volume) of the adhesive member 5 becomes larger will be described. First, the Fabry-Perot interference filter 10 and the photodetector 1A are configured by interposing the second portion 5b between the placement surface 4a of each spacer 4A, 4B and the bottom surface 101 of the Fabry-Perot interference filter 10. The stress generated in the Fabry-Perot interference filter 10 due to the difference in the coefficient of thermal expansion with other members is absorbed, and as a result, the generation of the stress in the Fabry-Perot interference filter 10 is suppressed. Next, as the amount of the first portions 5a arranged in the corners C1, C2, C3, C4, C5, C6 becomes larger, the thermal stress generated in the CAN package 6 (stress generated from various areas and directions). Is sufficiently recovered (absorption amount of thermal stress by the adhesive member 5>amount of thermal stress generated in the CAN package 6), the temperature characteristic of the transmission wavelength in the Fabry-Perot interference filter 10 is improved.

Further, since the first portions 5a arranged at the corners C1, C2, C3, C4, C5, C6 are formed in a fillet shape so as to crawl up the side surface 102 of the Fabry-Perot interference filter 10, each spacer 4A is formed. , 4B between the mounting surfaces 4a and the bottom surface 101 of the Fabry-Perot interference filter 10, and the Fabry-Perot interference filter 10 is held not only from the outside of the side surface 102. Therefore, the holding state of the Fabry-Perot interference filter 10 on the spacers 4A and 4B becomes stable. As described above, the configuration of the adhesive member 5 in the photodetector 1A is to improve the temperature characteristics of the transmission wavelength of the Fabry-Perot interference filter 10 and to stabilize the holding state of the Fabry-Perot interference filter 10 on the spacers 4A and 4B. It is possible to achieve both.

Further, in the adhesive member 5, the value obtained by subtracting the thickness of the second portion 5b in the direction perpendicular to the mounting surface 4a from the height H of the first portion 5a in the direction perpendicular to the mounting surface 4a is It is larger than the thickness of the second portion 5b in the direction perpendicular to the surface 4a. Thereby, the stress generated in the Fabry-Perot interference filter 10 due to the difference in the thermal expansion coefficient between the Fabry-Perot interference filter 10 and the other members constituting the photodetector 1A is more sufficiently absorbed by the adhesive member 5. be able to.

The width W of the first portion 5a in the direction perpendicular to the side surface 102 of the Fabry-Perot interference filter 10 is larger than the height H of the first portion 5a in the direction perpendicular to the mounting surface 4a of each spacer 4A, 4B. Then, it is possible to more surely achieve both the improvement of the temperature characteristics of the transmission wavelength in the Fabry-Perot interference filter 10 and the stabilization of the holding state of the Fabry-Perot interference filter 10 on the spacers 4A and 4B. Therefore, it is preferable that the adhesive member 5 is in contact over the entire width of the portion of the placement surface 4a that projects to the outside of the side surface 102.

Further, in the photodetector 1A, the adhesive members 5 arranged at the corners C1, C2, C3, C4, C5 and C6 are in contact with the substrate 14 on the side surface 102 of the Fabry-Perot interference filter 10. Thereby, the stress generated in the Fabry-Perot interference filter 10 due to the difference in the thermal expansion coefficient between the Fabry-Perot interference filter 10 and the other members constituting the photodetector 1A is more sufficiently absorbed by the adhesive member 5. be able to. In addition, since the substrate 14 supporting the first mirror 31 and the second mirror 41 is held from the outside by the adhesive member 5, the holding state of the Fabry-Perot interference filter 10 can be further stabilized.

In addition, in the photodetector 1A, the adhesive member 5 is arranged at the corner C1 so as to be continuous over the entire corner C1 formed by the side surface 102a of the Fabry-Perot interference filter 10, and is provided on the side surface 102a. Are in contact. Similarly, the adhesive member 5 is arranged at the corner C4 so as to be continuous over the entire corner C4 formed by the side surface 102b of the Fabry-Perot interference filter 10, and is in contact with the side surface 102b. Thereby, for example, when the plurality of adhesive members 5 are intermittently arranged at the corners C1 and C4, or the adhesive member 5 is arranged at only one position in a part of the corners C1 and C4. Compared with the case, the adhesive member 5 uniformly absorbs the stress generated in the Fabry-Perot interference filter 10 due to the difference in thermal expansion coefficient between the Fabry-Perot interference filter 10 and other members constituting the photodetector 1A. be able to.

In particular, if the height H and the width W of the first portion 5a of the adhesive member 5 are uniform, the thermal stress generated in the CAN package 6 can be more uniformly absorbed by the adhesive member 5. Such an adhesive member 5 is formed as follows. That is, an adhesive containing, for example, a silicone-based resin material is applied to the mounting surfaces 4a of the spacers 4A and 4B with a uniform thickness, and the Fabry-Perot interference filter 10 is mounted thereon, and in that state. , The adhesive is thermoset, for example. When the Fabry-Perot interference filter 10 is placed, the adhesive present between the placement surfaces 4a of the respective spacers 4A and 4B and the bottom surface 101 of the Fabry-Perot interference filter 10 is uniform due to the weight of the Fabry-Perot interference filter 10. It will be thick. Further, the adhesive present in the corners C1, C2, C3, C4, C5, C6 crawls up the side surface 102 of the Fabry-Perot interference filter 10 to have a uniform height and width. In this way, the adhesive member 5 including the first portion 5a having a uniform height H and width W is formed.

The Fabry-Perot interference filter 10 is placed on the placement surface 4a of each of the spacers 4A and 4B, and thereafter, an adhesive containing, for example, a silicone-based resin material is applied to the corners C1, C2, C3, C4, C5. It may be applied at a uniform thickness along C6, after which the adhesive may be heat cured, for example. Also in this case, when the adhesive is applied along the corners C1, C2, C3, C4, C5 and C6, the mounting surfaces 4a of the spacers 4A and 4B and the bottom surface 101 of the Fabry-Perot interference filter 10 are separated. An adhesive enters between them, and the adhesive has a uniform thickness due to its own weight of the Fabry-Perot interference filter 10. Further, the adhesive present in the corners C1, C2, C3, C4, C5, C6 crawls up the side surface 102 of the Fabry-Perot interference filter 10 to have a uniform height and width. Alternatively, of the mounting surfaces 4a of the spacers 4A and 4B, only the region where the bottom surface 101 of the Fabry-Perot interference filter 10 is mounted is coated with an adhesive containing, for example, a silicone resin material, and then the Fabry-Perot The interference filter 10 is placed, and then the adhesive is heat-cured, for example, and then the adhesive containing a silicone-based resin material is uniformly applied along the corners C1, C2, C3, C4, C5, C6. The adhesive may be applied, for example, by thermosetting. Also in this case, when the Fabry-Perot interference filter 10 is placed, the adhesive existing between the placement surfaces 4a of the spacers 4A and 4B and the bottom surface 101 of the Fabry-Perot interference filter 10 is the Fabry-Perot interference filter. A uniform thickness is obtained by the weight of 10. Further, the adhesive existing in the corners C1, C2, C3, C4, C5, C6 has a uniform height and width on the side surface 102 of the Fabry-Perot interference filter 10.

Further, in the photodetector 1A, the adhesive member 5 is arranged in the corner C1 formed by the side surface 102a of the Fabry-Perot interference filter 10 and is in contact with the side surface 102a. Further, the adhesive member 5 is arranged at the corner C4 formed by the side surface 102b of the Fabry-Perot interference filter 10 facing the side surface 102a with the light transmission region 11 interposed therebetween, and is in contact with the side surface 102b. This allows the Fabry-Perot interference filter 10 to be held on the spacers 4A and 4B in a more stable state.

In particular, when a material having an extremely small Young's modulus (Young's modulus of less than 10 MPa) (for example, a silicone-based resin material) is used as the material of the adhesive member 5, the side surfaces 102a and 102b facing each other are formed. Even if the adhesive member 5 is arranged at each of the corners C1 and C4 formed by each of them, the Fabry-Perot interference filter 10 is prevented from being distorted due to the thermal stress generated in the CAN package 6, and rather, is CAN. The thermal stress generated in the package 6 is absorbed by the adhesive member 5.

In the photodetector 1A, the adhesive members 5 arranged at the corners C1, C2, C3 are continuous with each other and cover the corners 103a, 103b of the Fabry-Perot interference filter 10 from the outside. Similarly, the adhesive members 5 arranged at the corners C4, C5, C6 are continuous with each other and cover the corners 103c, 103d of the Fabry-Perot interference filter 10 from the outside. As a result, the stress generated in the Fabry-Perot interference filter 10 due to the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter 10 and the other members of the photodetector 1A is likely to concentrate on the corners 103a, 103b, In 103c and 103d, the stress can be sufficiently absorbed by the adhesive member 5.

Further, in the photodetector 1A, the adhesive member 5 is not provided on the entire bottom surface 101 of the Fabry-Perot interference filter 10 (especially, because the adhesive member 5 is not provided in the light transmission region 11), the following effects are obtained. Played. That is, since the light transmitted through the Fabry-Perot interference filter 10 does not pass through the adhesive member 5, it is not necessary to select the adhesive member 5 having a high light transmittance, and the degree of freedom in selecting the adhesive member 5 is improved. Further, since the light that has passed through the Fabry-Perot interference filter 10 does not pass through the adhesive member 5, the light that passes through the Fabry-Perot interference filter 10 has optical characteristics (refractive index, transmittance, etc.) of the adhesive member 5 that accompany changes in the ambient temperature. ) Is not affected by the change. Further, the Fabry-Perot interference filter 10 is distorted or tilted due to the contraction of the adhesive member 5 at the time of curing and the stress generated by the expansion and contraction of the adhesive member 5 due to the change of the ambient temperature during use. Is suppressed.
[Second Embodiment]
[Configuration of photodetector]

As shown in FIG. 5, the photodetector 1B is different from the above-described photodetector 1A in that it is configured as an SMD (Surface Mount Device). The photodetector 1</b>B includes an SMD package 7 that houses the photodetector 3, a temperature compensation element (not shown), and the Fabry-Perot interference filter 10. The SMD package 7 has a first layer substrate 71, a second layer substrate 72, a third layer substrate 73, a fourth layer substrate 74, a fifth layer substrate 75 and a sixth layer substrate 76.

The first layer substrate 71, the second layer substrate 72, the third layer substrate 73, the fourth layer substrate 74, the fifth layer substrate 75 and the sixth layer substrate 76 are laminated in this order. An opening is provided at the center of each of the second layer substrate 72, the third layer substrate 73, the fourth layer substrate 74, and the fifth layer substrate 75. When viewed from the direction A, the opening of the third layer substrate 73 includes the opening of the second layer substrate 72. When viewed from the direction A, the opening of the fourth layer substrate 74 includes the opening of the third layer substrate 73. When viewed from the direction A, the opening of the fifth layer substrate 75 includes the opening of the fourth layer substrate 74. As a result, a part of the surface of each of the first layer substrate 71, the second layer substrate 72, the third layer substrate 73, and the fourth layer substrate 74 is exposed in the opening of the fifth layer substrate 75.

The photodetector 3 and a temperature compensation element (not shown) are mounted on the exposed surface of the first layer substrate 71. A plurality of electrode pads 77 are provided on the back surface of the first layer substrate 71. Each terminal of the photodetector 3 and each terminal of the temperature compensating element is connected to the electrode pad 77 by the wiring provided on the first layer substrate 71 or the wire 8 and the wiring provided on each substrate 71, 72. Is electrically connected to.

The Fabry-Perot interference filter 10 is fixed to the exposed surface of the third layer substrate 73 by an adhesive member 5. The upper surfaces of the terminals 12 and 13 of the Fabry-Perot interference filter 10 are at the same height as the upper surface of the fourth layer substrate 74. Pads electrically connected to the electrode pads 77 are provided on the upper surface of the fourth layer substrate 74, and the terminals 12 and 13 are connected to the pads on the upper surface of the fourth layer substrate 74 by the wires 8. There is. The terminals 12, 13 of the Fabry-Perot interference filter 10 are electrically connected to the electrode pads 77 by the wires 8 and the wirings provided on the substrates 71, 72, 73, 74. The third layer substrate 73 functions as a support member that supports the Fabry-Perot interference filter 10 on the first layer substrate 71 and the second layer substrate 72.

As a material of the first layer substrate 71, the second layer substrate 72, the third layer substrate 73, the fourth layer substrate 74, and the fifth layer substrate 75, for example, ceramic, resin, or the like can be used. In particular, in order to reduce the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter 10 and the third-layer substrate 73, the material of the third-layer substrate 73 has a higher thermal conductivity than the material of the Fabry-Perot interference filter 10. It is preferable that the expansion coefficients are the same.

As a material of the adhesive member 5 for adhering the Fabry-Perot interference filter 10 and the third layer substrate 73, a flexible resin material (for example, a resin material such as a silicone-based, urethane-based, epoxy-based, acrylic-based or hybrid resin material) is used. And may be conductive or non-conductive). The resin material is preferably selected from materials having a Young's modulus of less than 1000 MPa, and more preferably selected from materials having a Young's modulus of less than 10 MPa. Further, as the resin material, it is preferable to select a material whose glass transition temperature is out of the operating environment temperature of the photodetector 1B. For example, if an adhesive containing a silicone-based resin material is used as the material of the adhesive member 5, the Young's modulus after curing is less than 10 MPa, and the glass transition temperature is the operating environment temperature (for example, about 5 to 40° C.). Which is lower than that of -50 to -40°C.

Here, the elastic modulus of the adhesive member 5 that bonds the Fabry-Perot interference filter 10 and the third layer substrate 73 is smaller than the elastic modulus of the third layer substrate 73. Further, the elastic modulus of the adhesive member 5 for adhering the Fabry-Perot interference filter 10 and the third layer substrate 73 is determined by the first layer substrate 71, the second layer substrate 72, the third layer substrate 73, the fourth layer substrate 74, and the fourth layer substrate 74. It is smaller than the elastic modulus of an adhesive member (not shown) that adheres the five-layer substrate 75 and the sixth-layer substrate 76 to each other. For example, as a material of an adhesive member for adhering the first layer substrate 71, the second layer substrate 72, the third layer substrate 73, the fourth layer substrate 74, the fifth layer substrate 75 and the sixth layer substrate 76 to each other, an epoxy-based material is used. When an adhesive containing a resin material is used, the Young's modulus after curing is 100 MPa or more.

The sixth layer substrate 76 has a light transmitting substrate 76a and a light shielding layer 76b. The light transmitting substrate 76a is fixed on the fifth layer substrate 75 by an adhesive member (not shown). As the material of the light transmitting substrate 76a, a material (for example, glass, silicon, germanium, etc.) corresponding to the measurement wavelength range of the photodetector 1B can be used. The light shielding layer 76b is formed on the surface of the light transmitting substrate 76a. As the material of the light shielding layer 76b, a light shielding material or a light absorbing material (for example, metal such as aluminum, metal oxide such as chromium oxide, black resin, etc.) can be used. An opening 76c is provided in the light shielding layer 76b. The light transmitting region 11 and the opening 76c face each other in the direction A. The light shielding layer 76b may be formed on the back surface of the light transmitting substrate 76a. Further, a light reflection preventing layer may be formed on at least one of the front surface and the back surface of the light transmitting substrate 76a. Further, as the light transmission substrate 76a, a bandpass filter that transmits only light in the measurement wavelength range may be used.

In the light detection device 1B configured as described above, when light is incident on the light transmission region 11 of the Fabry-Perot interference filter 10 from the outside through the opening 76c and the light transmission substrate 76a, the first mirror in the light transmission region 11 is detected. Light having a predetermined wavelength is selectively transmitted in accordance with the distance between 31 and the second mirror 41. The light transmitted through the first mirror 31 and the second mirror 41 is incident on the light receiving section 3 a of the photodetector 3 and detected by the photodetector 3. In the photodetector 1B, while changing the voltage applied to the Fabry-Perot interference filter 10 (that is, changing the distance between the first mirror 31 and the second mirror 41), the first mirror 31 and the second mirror 41 are A spectrum can be obtained by detecting the transmitted light with the photodetector 3.
[Structure of Adhesive Member for Bonding Fabry-Perot Interference Filter and Third Layer Substrate]

The configuration of the adhesive member 5 will be described in more detail with reference to FIGS. 5 and 6. The sixth layer substrate 76 and the like are omitted in FIG.

As shown in FIGS. 5 and 6, the mounting surface 73 a of the third layer substrate 73 is a portion of the bottom surface 101 of the Fabry-Perot interference filter 10 that is outside the light transmission region 11 and that has Fabry-Perot interference. The portion along the side surface 102 of the filter 10 is placed. The Fabry-Perot interference filter 10 has a rectangular side surface 102 when viewed from the direction A. Among the side surfaces 102, the side surface (first side surface, second side surface) 102a and the side surface (first side surface, third side surface) 102b are opposed to each other with the light transmission region 11 interposed therebetween.

The side surface 102a is located on the mounting surface 73a such that a part of the mounting surface 73a is arranged outside the side surface 102a (outside the side surface 102 when viewed from the direction A). As a result, a corner C1 is formed by the side surface 102a and a portion of the mounting surface 73a outside the side surface 102a (a portion exposed without the Fabry-Perot interference filter 10 being mounted). One end portion of the side surface (fifth side surface) 102c of the side surface 102 that forms the corner portion 103a together with the side surface (fourth side surface) 102a has a corner 103a side, and a part of the mounting surface 73a is arranged outside the side surface 102c. Thus, it is located on the mounting surface 73a. As a result, the corner C2 is formed between the one end of the side surface 102c and the portion of the placement surface 73a outside the one end of the side surface 102c (the exposed portion without the Fabry-Perot interference filter 10 placed). Are formed. One end portion of the side surface (fifth side surface) 102d on the side of the corner portion 103b that forms the corner portion 103b together with the side surface (fourth side surface) 102a has a part of the mounting surface 73a disposed outside the side surface 102d. Thus, it is located on the mounting surface 73a. As a result, the corner C3 is formed between the one end of the side surface 102d and the portion of the mounting surface 73a outside the one end of the side surface 102d (exposed portion where the Fabry-Perot interference filter 10 is not mounted). Are formed. Note that the side surfaces 102a, the one ends of the side surfaces 102c, and the one end of the side surfaces 102d correspond to a part of the outer edge of the Fabry-Perot interference filter 10 when viewed from the direction A.

The side surface 102b is located on the mounting surface 73a so that a part of the mounting surface 73a is arranged outside the side surface 102b. As a result, a corner C4 is formed by the side surface 102b and a portion of the mounting surface 73a outside the side surface 102b (a portion where the Fabry-Perot interference filter 10 is not mounted and is exposed). The other end of the side surface (fifth side surface) 102c of the side surface 102, which forms the corner portion 103c with the side surface (fourth side surface) 102b, on the side of the corner portion 103c has a part of the mounting surface 73a disposed outside the side surface 102c. As described above, it is located on the mounting surface 73a. As a result, the corner between the other end of the side surface 102c and the portion of the mounting surface 73a outside the other end of the side surface 102c (exposed portion where the Fabry-Perot interference filter 10 is not mounted) is formed. The part C5 is formed. The other end of the side surface (fifth side surface) 102d on the side of the corner portion 103d that forms the corner portion 103d together with the side surface (fourth side surface) 102b has a part of the mounting surface 73a disposed outside the side surface 102d. As described above, it is located on the mounting surface 73a. As a result, the corner between the other end of the side surface 102d and the portion of the mounting surface 73a outside the other end of the side surface 102d (the exposed portion without the Fabry-Perot interference filter 10 mounted) is formed. The part C6 is formed. The other ends of the side face 102b, the side face 102c, and the other end of the side face 102d correspond to part of the outer edge of the Fabry-Perot interference filter 10 when viewed from the direction A.

The adhesive member 5 is arranged at each corner C1, C2, C3. The adhesive members 5 arranged at the corners C1, C2, C3 are continuous with each other. That is, the adhesive member 5 arranged in each of the corners C1, C2, C3 is continuous over the entire corner C1 and covers each of the corners 103a, 103b from the outside. Similarly, the adhesive member 5 is arranged at each corner C4, C5, C6. The adhesive members 5 arranged at the corners C4, C5, C6 are continuous with each other. That is, the adhesive member 5 arranged at each corner C4, C5, C6 is continuous over the entire corner C4 and covers each corner 103c, 103d from the outside.

The adhesive member 5 arranged at each corner C1, C2, C3 includes a first portion 5a and a second portion 5b. The first portion 5a is a portion arranged along each corner C1, C2, C3, and is continuous via each corner 103a, 103b. The second portion 5b is a portion disposed between the mounting surface 73a of the third layer substrate 73 and the bottom surface 101 of the Fabry-Perot interference filter 10. In the corner C1, the first portion 5a is in contact with each of the side surface 102a, the mounting surface 73a, and the inner surface 74a of the opening of the fourth layer substrate 74. In the corner C2, the first portion 5a is in contact with one end of the side surface 102c, the mounting surface 73a, and the inner surface 74a of the opening of the fourth layer substrate 74, respectively. In the corner C3, the first portion 5a is in contact with one end of the side surface 102d, the mounting surface 73a, and the inner surface 74a of the opening of the fourth layer substrate 74, respectively. That is, the adhesive members 5 arranged at the corners C1, C2, C3 are in contact with the side surface 102, the mounting surface 73a and the inner surface 74a of the opening of the fourth layer substrate 74, respectively.

Similarly, the adhesive member 5 arranged at each of the corners C4, C5, C6 includes a first portion 5a and a second portion 5b. The first portion 5a is a portion arranged along the corners C4, C5, C6, and is continuous via the corners 103c, 103d. The second portion 5b is a portion disposed between the mounting surface 73a of the third layer substrate 73 and the bottom surface 101 of the Fabry-Perot interference filter 10. In the corner C4, the first portion 5a is in contact with each of the side surface 102b, the placement surface 73a, and the inner surface 74a of the opening of the fourth layer substrate 74. In the corner C5, the first portion 5a is in contact with the other end of the side surface 102c, the mounting surface 73a, and the inner surface 74a of the opening of the fourth layer substrate 74, respectively. In the corner C6, the first portion 5a is in contact with the other end of the side surface 102d, the mounting surface 73a, and the inner surface 74a of the opening of the fourth layer substrate 74, respectively. That is, the adhesive members 5 arranged at the corners C4, C5, C6 are in contact with the side surface 102, the mounting surface 73a, and the inner surface 74a of the opening of the fourth layer substrate 74, respectively.

In each of the corners C1, C2, C3, the edge portion 5c on the side of the highest side surface 102 of the first portion 5a reaches the side surface of the substrate 14 of the Fabry-Perot interference filter 10. That is, the adhesive members 5 arranged at the corners C1, C2, C3 are in contact with the substrate 14 on the side surface 102. Similarly, in each of the corners C4, C5, C6, the edge portion 5c on the side of the highest side surface 102 of the first portion 5a reaches the side surface of the substrate 14 of the Fabry-Perot interference filter 10. That is, the adhesive members 5 arranged at the corners C4, C5, C6 are in contact with the substrate 14 on the side surface 102. The height of the edge portion 5c is lower than the height of the Fabry-Perot interference filter 10 and the fourth layer substrate 74. Further, in the adhesive member 5, a value obtained by subtracting the thickness of the second portion 5b in the direction perpendicular to the mounting surface 73a from the height H of the first portion 5a in the direction perpendicular to the mounting surface 73a (Fabry-Perot interference). The height of the edge portion 5c from the bottom surface 101 of the filter 10 is larger than the thickness of the second portion 5b in the direction perpendicular to the mounting surface 73a.
[Action and effect]

In the photodetector 1B, the adhesive member 5 having an elastic modulus smaller than that of the third layer substrate 73 is arranged at the corners C1, C2, C3, C4, C5, C6, and the Fabry-Perot interference filter The side surface 102 and a part of the mounting surface 73a of the third layer substrate 73 are in contact with each other. Accordingly, for example, as compared with the case where the adhesive member 5 is only interposed between the bottom surface 101 of the Fabry-Perot interference filter 10 and the mounting surface 73a of the third layer substrate 73, the Fabry-Perot interference filter 10 and the light Other members constituting the detection device 1B (not only the third layer substrate 73, but also the first layer substrate 71, the second layer substrate 72, the fourth layer substrate 74, the fifth layer substrate 75, the sixth layer substrate 76, etc.) The stress generated in the Fabry-Perot interference filter 10 due to the difference in the coefficient of thermal expansion between and can be sufficiently absorbed by the adhesive member 5. Further, for example, the Fabry-Perot interference filter 10 is stabilized compared to the case where the adhesive member 5 is only interposed between the bottom surface 101 of the Fabry-Perot interference filter 10 and the mounting surface 73a of the third layer substrate 73. In this state, it can be more firmly held on the third layer substrate 73. Therefore, according to the photodetector 1B, it is possible to sufficiently improve the temperature characteristics of the transmission wavelength in the Fabry-Perot interference filter 10 and stabilize the holding state of the Fabry-Perot interference filter 10 on the third layer substrate 73. You can The adhesive member 5 is the other member (not only the third layer substrate 73) constituting the photodetector 1B but also the Fabry-Perot interference filter 10, the first layer substrate 71, the second layer substrate 72, and the fourth layer substrate 74. , The fifth-layer substrate 75, the sixth-layer substrate 76, etc.).

Further, in the adhesive member 5, the value obtained by subtracting the thickness of the second portion 5b in the direction perpendicular to the mounting surface 73a from the height H of the first portion 5a in the direction perpendicular to the mounting surface 73a is It is larger than the thickness of the second portion 5b in the direction perpendicular to the surface 73a. Thereby, the stress generated in the Fabry-Perot interference filter 10 due to the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter 10 and the other members forming the photodetector 1B is more sufficiently absorbed by the adhesive member 5. be able to.

The width W of the first portion 5a in the direction perpendicular to the side surface 102 of the Fabry-Perot interference filter 10 is larger than the height H of the first portion 5a in the direction perpendicular to the mounting surface 73a of the third layer substrate 73. Then, it is possible to more reliably realize both the improvement of the temperature characteristics of the transmission wavelength in the Fabry-Perot interference filter 10 and the stabilization of the holding state of the Fabry-Perot interference filter 10 on the third layer substrate 73. Therefore, it is preferable that the adhesive member 5 is in contact over the entire width of the portion of the placement surface 73a that projects to the outside of the side surface 102.

Further, in the photodetector 1B, the adhesive members 5 arranged at the corners C1, C2, C3, C4, C5, C6 are in contact with the substrate 14 on the side surface 102 of the Fabry-Perot interference filter 10. Thereby, the stress generated in the Fabry-Perot interference filter 10 due to the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter 10 and the other members forming the photodetector 1B is more sufficiently absorbed by the adhesive member 5. be able to. In addition, since the substrate 14 supporting the first mirror 31 and the second mirror 41 is held from the outside by the adhesive member 5, the holding state of the Fabry-Perot interference filter 10 can be further stabilized.

In addition, in the photodetector 1B, the adhesive member 5 is arranged at the corner C1 so as to be continuous over the entire corner C1 formed by the side surface 102a of the Fabry-Perot interference filter 10, and the adhesive member 5 is provided on the side surface 102a. Are in contact. Similarly, the adhesive member 5 is arranged at the corner C4 so as to be continuous over the entire corner C4 formed by the side surface 102b of the Fabry-Perot interference filter 10, and is in contact with the side surface 102b. Thereby, for example, when the plurality of adhesive members 5 are intermittently arranged at the corners C1 and C4, or the adhesive member 5 is arranged at only one position in a part of the corners C1 and C4. Compared with the case, the adhesive member 5 uniformly absorbs the stress generated in the Fabry-Perot interference filter 10 due to the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter 10 and other members constituting the photodetector 1B. be able to.

In addition, in the photodetector 1B, the adhesive member 5 is arranged at the corner C1 formed by the side surface 102a of the Fabry-Perot interference filter 10 and is in contact with the side surface 102a. Further, the adhesive member 5 is arranged at the corner C4 formed by the side surface 102b of the Fabry-Perot interference filter 10 facing the side surface 102a with the light transmission region 11 interposed therebetween, and is in contact with the side surface 102b. Accordingly, the Fabry-Perot interference filter 10 can be held on the third layer substrate 73 in a more stable state.

In the photodetector 1B, the adhesive members 5 arranged at the corners C1, C2, C3 are continuous with each other and cover the corners 103a, 103b of the Fabry-Perot interference filter 10 from the outside. Similarly, the adhesive members 5 arranged at the corners C4, C5, C6 are continuous with each other and cover the corners 103c, 103d of the Fabry-Perot interference filter 10 from the outside. As a result, the stress generated in the Fabry-Perot interference filter 10 due to the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter 10 and the other members of the photodetector 1B is likely to concentrate on the corners 103a, 103b, In 103c and 103d, the stress can be sufficiently absorbed by the adhesive member 5.

Further, in the photodetector 1B, the adhesive member 5 is not provided on the entire bottom surface 101 of the Fabry-Perot interference filter 10 (especially, since the adhesive member 5 is not provided in the light transmission region 11), the following effects are obtained. Played. That is, since the light transmitted through the Fabry-Perot interference filter 10 does not pass through the adhesive member 5, it is not necessary to select the adhesive member 5 having a high light transmittance, and the degree of freedom in selecting the adhesive member 5 is improved. Further, since the light that has passed through the Fabry-Perot interference filter 10 does not pass through the adhesive member 5, the light that passes through the Fabry-Perot interference filter 10 has optical characteristics (refractive index, transmittance, etc.) of the adhesive member 5 that accompany changes in the ambient temperature. ) Is not affected by the change. Further, the Fabry-Perot interference filter 10 is distorted or tilted due to the contraction of the adhesive member 5 at the time of curing and the stress generated by the expansion and contraction of the adhesive member 5 due to the change of the ambient temperature during use. Is suppressed.

Further, in the photodetector 1B, horizontally long spaces (spaces in which the width in the direction perpendicular to the direction A is larger than the width in the direction parallel to the direction A) are provided on both sides of the Fabry-Perot interference filter in the direction A. Further, in the photodetection device 1B, when viewed from the direction A, the outer edges of the spaces provided on both sides of the Fabry-Perot interference filter in the direction A are defined by the inner edge of the SMD package 7. Further, in the photodetector 1B, the space provided on the light incident side of the Fabry-Perot interference filter 10 is wider than the space provided on the light emitting side of the Fabry-Perot interference filter 10 in the direction perpendicular to the direction A. Is big. On the other hand, in the photodetector 1B, the space provided on the light emission side of the Fabry-Perot interference filter 10 is parallel to the direction A rather than the space provided on the light incident side of the Fabry-Perot interference filter 10. The width of is large. Further, in the photodetection device 1B, the Fabry-Perot interference filter 10 is electrically connected to the plurality of electrode pads 77 provided on the bottom surface of the SMD package 7 via the wiring provided on the SMD package 7.

As described above, the photodetector 1B can be downsized. Further, by providing the horizontally long spaces on both sides of the Fabry-Perot interference filter in the direction A, the distance between the opening 76c of the sixth layer substrate 76 and the Fabry-Perot interference filter 10 can be increased as compared with the case where the vertically long space is provided, Also, the distance between the Fabry-Perot interference filter 10 and the photodetector 3 can be kept small. Therefore, even if the light is slightly obliquely incident from the opening 76c, the incident light is transmitted through the light transmission region 11 of the Fabry-Perot interference filter 10 and the transmitted light is incident on the light receiving portion 3a of the photodetector 3. You can Further, by providing the horizontally long spaces on both sides of the Fabry-Perot interference filter in the direction A, the height of the members constituting the SMD package 7 can be reduced as compared with the case where the vertically long space is provided, and the SMD package 7 The volume of can be kept small. Therefore, it is possible to suppress the generation of stress due to the difference in thermal expansion coefficient between the Fabry-Perot interference filter 10 and the SMD package 7.

Although the first and second embodiments of the present invention have been described above, the present invention is not limited to the above-described first and second embodiments. For example, in the first embodiment, the adhesive member 5 includes the second portion 5b arranged between the mounting surface 4a of the spacer 4A and the bottom surface 101 of the Fabry-Perot interference filter 10, but the adhesive member 5 is As long as the first portion 5a is included, the second portion 5b may not be included. Similarly, in the second embodiment, the adhesive member 5 includes the second portion 5b arranged between the mounting surface 73a of the third layer substrate 73 and the bottom surface 101 of the Fabry-Perot interference filter 10. The adhesive member 5 need not include the second portion 5b as long as it includes the first portion 5a. If the adhesive member 5 includes the first portion 5a, the temperature characteristics of the transmission wavelength in the Fabry-Perot interference filter 10 can be sufficiently improved, and the holding state of the Fabry-Perot interference filter 10 can be stabilized. Further, the material and shape of each component are not limited to the above-described materials and shapes, and various materials and shapes can be adopted.

Further, in the second embodiment, the first layer substrate 71, the second layer substrate 72, the third layer substrate 73, the fourth layer substrate 74, and the fifth layer substrate 75 are formed separately from each other, but FIG. As shown in, the bottom surface 101 of the Fabry-Perot interference filter 10 may be mounted on the mounting surface 70a of the supporting body (supporting body) 70 corresponding to one in which those substrates are integrally formed. In this case, compared with the case where the first layer substrate 71, the second layer substrate 72, the third layer substrate 73, the fourth layer substrate 74, and the fifth layer substrate 75 are overlapped with each other and adhered, the formed SMD package There is little variation in shape for each 7. Moreover, since an adhesive member for adhering the first layer substrate 71, the second layer substrate 72, the third layer substrate 73, the fourth layer substrate 74, the fifth layer substrate 75, and the sixth layer substrate 76 to each other is not necessary, The change in shape of the SMD package 7 due to the expansion and contraction of the adhesive member due to the change in temperature is suppressed. Further, since it is possible to prevent moisture contained in the outside air from entering the inside of the SMD package 7 via the adhesive member 5, the adhesive member 5 between the Fabry-Perot interference filter 10 and the SMD package 7 affects the influence of moisture. It is possible to prevent the deterioration. Therefore, in this case, the SMD package 7 having a more stable shape can be obtained.

Further, in the first and second embodiments, the edge portion 5c of the adhesive member 5 reaches the side surface of the substrate 14 of the Fabry-Perot interference filter 10, but the edge portion 5c of the adhesive member 5 does not reach the side surface of the substrate 14. The side surface of the laminated body 50 of the Fabry-Perot interference filter 10 may be reached. That is, the adhesive member 5 may not come into contact with the side surface of the substrate 14 but may come into contact with the side surface of the stacked body 50.

1A, 1B... Photodetector, 3... Photodetector, 4, 4A, 4B... Spacer (supporting member), 4a... Mounting surface, 5... Adhesive member, 5a... First part, 5b... Second part, 10 Fabry-Perot interference filter, 11... Light transmitting region, 14... Substrate, 31... First mirror, 41... Second mirror, 70... Support (support member), 70a... Mounting surface, 73... Third layer substrate ( Support member), 73a... Mounting surface, 101... Bottom surface, 102... Side surface, 102a... Side surface (first side surface, second side surface, fourth side surface), 102b... Side surface (first side surface, third side surface, fourth side surface) ), 102c, 102d... Side surface (fifth side surface), C1, C2, C3, C4, C5, C6... Corner portions.

Claims (13)

A Fabry-Perot interference filter having a first mirror and a second mirror whose distances are variable, and having a light transmission region that transmits light according to the distance between the first mirror and the second mirror,
A photodetector for detecting light transmitted through the light transmitting region,
A support member having a mounting surface on which a portion outside the light transmission region of the bottom surface of the Fabry-Perot interference filter is mounted;
An adhesive member for adhering the Fabry-Perot interference filter and the support member,
At least a part of the side surface of the Fabry-Perot interference filter is located on the mounting surface so that a part of the mounting surface is arranged outside the side surface,
The adhesive member is arranged at a corner formed by the side surface and the part of the mounting surface, and is in contact with each of the side surface and the part of the mounting surface,
The Fabry-Perot interference filter further includes a substrate supporting the first mirror and the second mirror,
The first mirror is composed of a dielectric multilayer film laminated on the light incident side with respect to the substrate,
The second mirror is composed of a dielectric multilayer film laminated on the light incident side with respect to the first mirror so as to face the first mirror via a gap,
The side surface of the dielectric multilayer film forming the second mirror forms a part of the side surface of the Fabry-Perot interference filter,
The photodetector, wherein the adhesive member does not reach the dielectric multilayer film forming the second mirror. The adhesive member includes a first portion arranged at the corner and a second portion arranged between the mounting surface and the bottom surface,
The value obtained by subtracting the thickness of the second portion in the direction perpendicular to the mounting surface from the height of the first portion in the direction perpendicular to the mounting surface is larger than the thickness of the second portion. The photodetector according to claim 1. The photodetector according to claim 1, wherein the adhesive member arranged at the corner is in contact with the substrate on the side surface of the Fabry-Perot interference filter . The side surface of the Fabry-Perot interference filter includes a first side surface,
The adhesive member is arranged in the corner formed by the first side surface so as to be continuous over the entire corner formed by the first side surface and is in contact with the first side surface. The photodetector according to any one of claims 1 to 3. The side surface of the Fabry-Perot interference filter includes a second side surface and a third side surface facing each other with the light transmission region interposed therebetween,
The adhesive member is arranged at each of the corner portion formed by the second side surface and the corner portion formed by the third side surface, and is in contact with each of the second side surface and the third side surface. The photodetector according to any one of claims 1 to 4. The side surface of the Fabry-Perot interference filter includes a fourth side surface and a fifth side surface forming a corner portion,
The adhesive member is arranged at each of the corner portion formed by the fourth side surface and the corner portion formed by the fifth side surface, and is in contact with each of the fourth side surface and the fifth side surface. The photodetector according to any one of claims 1 to 5. 7. The adhesive member arranged in the corner formed by the fourth side surface and the adhesive member arranged in the corner formed by the fifth side surface are continuous with each other. The photodetector described. A Fabry-Perot interference filter including a substrate, a first mirror and a second mirror whose distances are variable, and a light transmission region that transmits light according to the distance between the first mirror and the second mirror. When,
A photodetector for detecting light transmitted through the light transmitting region,
A support member having a mounting surface on which a portion outside the light transmission region of the bottom surface of the Fabry-Perot interference filter is mounted;
An adhesive member for adhering the Fabry-Perot interference filter and the support member,
The adhesive member is a first portion arranged outside the region between the mounting surface and the bottom surface, and a second portion disposed in the region between the mounting surface and the bottom surface, Including,
The thickness of the first portion in the thickness direction of the substrate is greater than the thickness of the second portion in the thickness direction of the substrate,
The first mirror is composed of a dielectric multilayer film laminated on the light incident side with respect to the substrate,
The second mirror is composed of a dielectric multilayer film laminated on the light incident side with respect to the first mirror so as to face the first mirror via a gap,
The side surface of the dielectric multilayer film forming the second mirror forms a part of the side surface of the Fabry-Perot interference filter,
The photodetection device in which the adhesive member does not reach the dielectric multilayer film forming the second mirror. The photodetector according to claim 8, wherein the first portion is arranged outside the second portion when the light transmission region is viewed from a direction in which light is transmitted. The photodetection device according to claim 9, wherein the adhesive member further includes a third portion disposed inside the second portion when the light transmission region is viewed from a direction in which light is transmitted. The photodetector according to claim 10, wherein a width of the first portion in a direction perpendicular to the thickness direction of the substrate is larger than a width of the third portion in a direction perpendicular to the thickness direction of the substrate. The photodetector according to claim 10, wherein the thickness of the first portion in the thickness direction of the substrate is larger than the thickness of the third portion in the thickness direction of the substrate. 13. The photodetector according to claim 8, wherein the elastic modulus of the adhesive member is smaller than the elastic modulus of the support member.

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