JP2020003502A - Optical detection device - Google Patents

Abstract

To provide an optical detection device equipped with a Fabry-Perot interference filter.SOLUTION: The optical detection device comprises: a Fabry-Perot interference filter having a light transmission area that allows light corresponding to the distance to first and second mirrors to pass through; an optical detector for detecting light having passed through the light transmission area; and a package for accommodating the Fabry-Perot interference filter and the optical detector. The package includes a support and a light transmissive substrate. Inside of the package are provided a first space on the light incident side of the Fabry-Perot interference filter in a direction in which light passes through the light transmission area and a second space on the light outgoing side of the Fabry-Perot interference filter in a direction in which light passes through the light transmission area. The width of each of the first and second spaces in a direction perpendicular to the direction in which light passes through the light transmission area is larger than the width in a direction parallel to the direction in which light passes through the light transmission area.SELECTED DRAWING: Figure 5

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 Literature 1 discloses an interference filter having a first reflection film and a second reflection film with variable distances, a substrate supporting the interference filter, and an adhesive layer interposed between the interference filter and the substrate. Are described. In the optical module described in Patent Literature 1, a gel resin is used for the adhesive layer in order to reduce stress generated in the interference filter due to a difference in thermal expansion coefficient between the interference filter and the substrate.

JP 2012-173347 A

  However, when the Fabry-Perot interference filter having the first mirror and the second mirror whose distance is variable and the support member are fixed, it is necessary to control the distance between the first mirror and the second mirror with extremely high precision. Therefore, only by interposing an adhesive layer made of a gel resin between the Fabry-Perot interference filter and the support member, the fluctuation of the stress generated in the Fabry-Perot interference filter due to a change in the use environment temperature or the like can be sufficiently achieved. As a result, the temperature characteristics of the transmission wavelength in the Fabry-Perot interference filter (temperature characteristics of the wavelength of light transmitted by the Fabry-Perot interference filter) may not be sufficiently improved. Further, when an adhesive layer made of a gel resin is used for fixing the Fabry-Perot interference filter to the support member, the holding state of the Fabry-Perot interference filter on the support member may be unstable.

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

  In this light detection device, an adhesive member having an elastic modulus smaller than the elastic modulus of the support member is disposed at a side surface of the Fabry-Perot interference filter and at a corner formed by a part of the mounting surface of the support member. , The side surface of the Fabry-Perot interference filter and a part of the mounting surface of the support member. Thereby, for example, the thermal expansion coefficient between the Fabry-Perot interference filter and the support member is smaller than that in the case where only the adhesive member is interposed between the bottom surface of the Fabry-Perot interference filter and the mounting surface of the support member. The stress generated in the Fabry-Perot interference filter due to the difference can be sufficiently absorbed by the adhesive member. Further, for example, the Fabry-Perot interference filter is more stably mounted on the support member in a stable state, compared with a case where an adhesive member is merely interposed between the bottom surface of the Fabry-Perot interference filter and the mounting surface of the support member. Can be held. Therefore, according to this photodetector, the temperature characteristics 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 light detection device according to the aspect of the invention, the adhesive member includes the first portion disposed at the corner and the second portion disposed 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 in 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 the coefficient of thermal expansion between the Fabry-Perot interference filter and the supporting member can be more sufficiently absorbed by the adhesive member.

  In the light detection device according to the aspect of the invention, the Fabry-Perot interference filter may further include a substrate that supports the first mirror and the second mirror, and the adhesive member disposed at a corner may be in contact with the substrate at a side surface. . Thereby, the stress generated in the Fabry-Perot interference filter due to the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter and the supporting member can be more sufficiently absorbed by the adhesive member. Further, 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 further stabilized.

  In the photodetector of the present invention, the side surface includes the first side surface, and the adhesive member is provided at 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 contact the first side surface. Thereby, for example, compared to a case where a plurality of adhesive members are intermittently arranged at a corner formed by the first side surface, the difference is caused by a difference in thermal expansion coefficient between the Fabry-Perot interference filter and the support member. Thus, the stress generated in the Fabry-Perot interference filter can be uniformly absorbed by the adhesive member.

  In the light detection device according to the aspect of the invention, the side surface includes the second side surface and the third side surface facing each other across the light transmission region, and the adhesive member is formed by the corner formed by the second side surface and the third side surface. It may be arranged at each of the corners formed and contact each of the second side surface and the third side surface. Thereby, the Fabry-Perot interference filter can 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, and the adhesive member has a corner formed by the fourth side surface and a corner formed by the fifth side surface. And may be in contact with each of the fourth side surface and the fifth side surface. This makes it possible for the adhesive member to sufficiently absorb the stress at the corner where stress generated in the Fabry-Perot interference filter due to the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter and the support member tends to concentrate. it can.

  In the photodetector of the present invention, the adhesive member disposed at the corner formed by the fourth side surface and the adhesive member disposed at the corner formed by the fifth side surface may be continuous with each other. . Thereby, in a corner portion where stress generated in the Fabry-Perot interference filter due to a difference in thermal expansion coefficient between the Fabry-Perot interference filter and the support member is likely to be concentrated, the stress can be more sufficiently absorbed by the adhesive member. Can be.

  According to the present invention, it is possible to provide a photodetector capable of sufficiently improving the temperature characteristic of a transmission wavelength in a Fabry-Perot interference filter and stabilizing a holding state of the Fabry-Perot interference filter on a support member. Becomes possible.

FIG. 2 is a cross-sectional view of the light detection device according to the first embodiment. FIG. 2 is a cross-sectional view of a Fabry-Perot interference filter of the photodetector 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. FIG. 2 is a cross-sectional view of a portion including a Fabry-Perot interference filter, a spacer, and an adhesive member in the photodetector of FIG. It is sectional drawing of the photodetector of 2nd Embodiment. FIG. 6 is a plan view of a portion including a Fabry-Perot interference filter, a third layer substrate, and an adhesive member in the photodetector of FIG. 5. It is sectional drawing of the modification of the photodetector of 2nd Embodiment.

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

  As shown in FIG. 1, the photodetector 1A 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 spectrum sensor that can obtain a 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 value is set 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 light transmitted through the light transmission region 11 of the Fabry-Perot interference filter 10 is detected by the photodetector 3.

  On the wiring board 2, a photodetector 3 and a temperature compensation element (not shown) such as a thermistor are mounted. As a substrate material of the wiring substrate 2, for example, silicon, ceramic, quartz, glass, plastic, or the like can be used. The photodetector 3 has a light receiving unit 3a that receives 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 light detector 3, for example, an infrared detector can be used. As the infrared detector, for example, a quantum sensor using InGaAs or the like, a thermal sensor using a thermopile or a bolometer, or the like can be used. When detecting light in the ultraviolet, visible, and near-infrared wavelength ranges, for example, a silicon photodiode or the like can be used as the photodetector 3. Further, the light detector 3 may be provided with one light receiving section 3a, or a plurality of light receiving sections 3a may be provided in an array. Further, 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 support members for supporting the Fabry-Perot interference filter 10 on the wiring board 2. The photodetector 3 is arranged in a space formed between the wiring board 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, in order to reduce the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter 10 and each of the spacers 4, the material of each spacer 4 has the same coefficient of thermal expansion as the material of the Fabry-Perot interference filter 10. It is preferable that Note that the wiring board 2 and the spacer 4 may be integrally formed. Further, the Fabry-Perot interference filter 10 may be supported not by the plurality of spacers 4 but by one spacer 4.

  The material of the adhesive member 5 for adhering the Fabry-Perot interference filter 10 and each spacer 4 is a resin material having flexibility (for example, a resin material such as a silicone-based, urethane-based, epoxy-based, acrylic-based, or hybrid 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 use 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 becomes less than 10 MPa, and the glass transition temperature becomes the use environment temperature (for example, about 5 to 40 ° C.). About -50 to -40 ° C.

  Here, the elastic modulus of the bonding 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 for bonding the Fabry-Perot interference filter 10 and each spacer 4 is smaller than the elastic modulus of the adhesive member (not shown) for bonding the wiring board 2 and each spacer 4. For example, if an adhesive containing an epoxy-based resin material is used as a material of an adhesive member for bonding the wiring board 2 and each spacer 4, the Young's modulus after curing becomes 100 MPa or more. The Young's modulus of the spacer 4 is 100 GPa or more when made of silicon, 100 GPa or more when made of ceramic, 10 GPa or more (generally 70 to 80 GPa) when made of glass, and Is 0.1 GPa or more. The elastic modulus is defined as Young's modulus (longitudinal elasticity: the relationship of strain to tensile or compressive stress), transverse elastic modulus (the relationship of strain to shear stress), and bulk modulus (pressure and volumetric strain under uniform compression). Relationship). That is, the Young's modulus is a specific example of the elastic modulus.

  The light detection device 1A further includes a CAN package 6. The CAN package 6 houses the above-described wiring board 2, photodetector 3, temperature compensation element (not shown), a plurality of spacers 4, a plurality of adhesive members 5, and a Fabry-Perot interference filter 10. 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 transmission region 11 and the opening 62a face each other in the direction A. As a material of the light transmitting member 63, a material (for example, glass, silicon, germanium, or the like) 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 transmitting 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. Each of the electrode pads provided on the wiring board 2, the terminal of the photodetector 3, the terminal of the temperature compensation element, and the terminals 12 and 13 of the Fabry-Perot interference filter 10 are each a plurality of lead pins 9 penetrating the stem 61. And are electrically connected by wires 8. Thereby, it is possible to input and output electric signals to and from each of the photodetector 3, the temperature compensation element, and the Fabry-Perot interference filter 10. In the photodetector 1A, since the spacers 4 are disposed immediately below the terminals 12 and 13 of the Fabry-Perot interference filter 10, wire bonding can be reliably performed.

In the light detection device 1A configured as described above, when light enters the light transmission region 11 of the Fabry-Perot interference filter 10 from the outside via the opening 62a and the light transmission member 63, the first mirror in the light transmission region 11 Light having a predetermined wavelength is selectively transmitted according to 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 is detected by the photodetector 3. In the photodetector 1A, the first mirror 31 and the second mirror 41 are changed while changing the voltage applied to the Fabry-Perot interference filter 10 (that is, while changing the distance between the first mirror 31 and the second mirror 41). By detecting the transmitted light with the photodetector 3, a spectrum can be obtained.
[Configuration 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 laminate 30, the sacrificial layer 16, and the second laminate 40 are laminated in this order on the surface 14a on the light incident side of the substrate 14. An air gap (air gap) S is formed between the first stacked body 30 and the second stacked body 40 by the frame-shaped sacrifice layer 16. 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 at the center 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 ／ of the center transmission wavelength (that is, the center 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 a 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 one by one. 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 1/4 of the center transmission wavelength. Note that a silicon oxide layer may be used instead of the silicon nitride layer.

  A portion of the second stacked body 40 corresponding to the light transmission region 11 functions as a second mirror 41 facing the first mirror 31 via the gap S. Similarly to 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 one by one. 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 center transmission wavelength. Note that a silicon oxide layer may be used instead of the silicon nitride layer.

  In the portion corresponding to the gap S in the second stacked body 40, a plurality of through holes 40b from the surface 40a of the second stacked body 40 to the gap S are provided so as to be uniformly distributed. The plurality of through holes 40b are formed to such an 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 gap S.

  The first electrode 17 is formed on the first mirror 31 so as to surround the light transmission region 11. 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 impurities into the polysilicon layer to reduce the resistance. The size of the second electrode 18 is preferably a size including the entire light transmitting region 11, but may be substantially the same as the size of the light transmitting 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 via the gap S in the direction A. The third electrode 19 is formed by doping impurities into the polysilicon layer 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 is.

  The terminal 12 is for applying a voltage to the Fabry-Perot interference filter 10. The terminals 12 are provided as a pair so as to face each other with the light transmitting 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 a wiring 21.

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

  On the surface 30a of the first stacked body 30, trenches 26 and 27 are provided. The trench 26 extends annularly so as to surround the wiring 23 extending from the terminal 13 in the direction A. The trench 26 electrically insulates the first electrode 17 from the wiring 23. The trench 27 extends annularly along the inner edge of the first electrode 17. The trench 27 electrically insulates the first electrode 17 from a region inside the first electrode 17. The area in each trench 26, 27 may be an insulating material or a void.

  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 sacrificial layer 16. The trench 28 electrically insulates the terminal 12 from the third electrode 19. The region in the trench 28 may be an insulating material or a void.

  An antireflection layer 51, a third laminated body 52, an intermediate layer 53, and a fourth laminated body 54 are laminated in this order on the surface 14b on the light emission side of the substrate 14. The anti-reflection layer 51 and the intermediate layer 53 have the same configuration as the anti-reflection layer 15 and the sacrificial layer 16, respectively. Each of the third stacked body 52 and the fourth stacked body 54 has a stacked structure that is symmetrical to the first stacked body 30 and the second stacked body 40 with respect to the substrate 14. The laminate 50 is configured by the antireflection layer 51, the third laminate 52, the intermediate layer 53, and the fourth laminate 54. The laminate 50 is disposed on the light emission side of the substrate 14 and has a function of suppressing the warpage of the substrate 14.

  For example, a columnar opening 50 a is formed in the laminate 50 so as to include the light transmission region 11. The opening 50a is open on the light emission side, and the bottom surface of the opening 50a reaches the antireflection layer 51. A light-shielding layer 29a is formed on a surface 50b on the light emission side of the laminate 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 on 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 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 transmission 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.
[Configuration of an adhesive member for adhering the Fabry-Perot interference filter and the spacer]

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

  As shown in FIG. 3, the Fabry-Perot interference filter 10 is supported by a pair of spacers 4A and 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 102a of the Fabry-Perot interference filter 10 is placed on the placement surface 4a of the spacer 4A. Have been. 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. Have been. 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 disposed outside the side surface 102a (outside of the side surface 102 when viewed from the direction A). ing. Thus, a corner C1 is formed by the side surface 102a and a portion of the mounting surface 4a of the spacer 4A outside the side surface 102a (a portion where the Fabry-Perot interference filter 10 is not mounted but is exposed). ing. One end of the side surface (fifth side surface) 102c, which forms the corner portion 103a together with the side surface (fourth side surface) 102a, on the corner 103a side is a part of the mounting surface 4a of the spacer 4A outside the side surface 102c. Is positioned on the mounting surface 4a of the spacer 4A. Thus, one end of the side surface 102c and a portion of the mounting surface 4a of the spacer 4A outside the one end of the side surface 102c (a portion where the Fabry-Perot interference filter 10 is not mounted and is exposed) A corner C2 is formed. One end of the side surface (fifth side surface) 102d that forms the corner portion 103b together with the side surface (fourth side surface) 102a of the side surface (fourth side surface) 102a is formed such that a part of the mounting surface 4a of the spacer 4A is outside the side surface 102d. Is positioned on the mounting surface 4a of the spacer 4A. Thus, 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 where the Fabry-Perot interference filter 10 is not mounted and is exposed) A corner C3 is formed. The above-described one end of the side surface 102a, the side surface 102c, and the one end of the side surface 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 such that a part of the mounting surface 4a of the spacer 4B is located outside the side surface 102b. Thereby, a corner C4 is formed by the side surface 102b and a portion of the mounting surface 4a of the spacer 4B outside the side surface 102b (a portion where the Fabry-Perot interference filter 10 is not mounted but is exposed). ing. The other end of the side surface (fifth side surface) 102c that forms the corner portion 103c together with the side surface (fourth side surface) 102b of the side surface 102 is closer to the corner portion 103c than the side surface 102c. It is located on the mounting surface 4a of the spacer 4B so as to be disposed outside. Accordingly, 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 where the Fabry-Perot interference filter 10 is not mounted and is exposed). Thus, a corner C5 is formed. The other end of the side surface (fifth side surface) 102d that forms the corner portion 103d together with the side surface (fourth side surface) 102b of the side surface 102b on the side of the corner portion 103d is a part of the mounting surface 4a of the spacer 4B. It is located on the mounting surface 4a of the spacer 4B so as to be disposed outside. Thereby, 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 where the Fabry-Perot interference filter 10 is not mounted and is exposed). Thus, a corner C6 is formed. The other ends of the side surfaces 102b and 102c and the other end of the side surface 102d correspond to a part of an 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 outside.

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

  As shown in FIG. 4, the adhesive member 5 disposed 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 disposed along each of the corners C1, C2, and C3, and is continuous via each of the corners 103a and 103b. The second portion 5b is a portion disposed between the mounting surface 4a of the spacer 4A and the bottom surface 101 of the Fabry-Perot interference filter 10. At 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. At 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 disposed 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 disposed 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 disposed along each of the corners C4, C5, and C6, and is continuous via each of the corners 103c and 103d. The second portion 5b is a portion disposed 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 disposed 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 corner 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, at each corner 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 disposed 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 a direction perpendicular to the mounting surface 4a of each of the spacers 4A and 4B and the width W of the first portion 5a in a direction perpendicular to the side surface 102 of the Fabry-Perot interference filter 10 are as follows. Each is 10 to 1000 μm. In addition, the thickness of the Fabry-Perot interference filter 10 is 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 protrudes outside the side surface 102 is 10 to 1000 μm. Here, the height H of the first portion 5a is preferably at least 1/10 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 emission 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 (Corresponding to 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, an adhesive member 5 having an elastic modulus smaller than the elastic modulus of each of the spacers 4A and 4B is disposed at the corners C1, C2, C3, C4, C5, and C6. It is in contact with the side surface 102 and a part of the mounting surface 4a of each of the spacers 4A and 4B. Thus, for example, the Fabry-Perot interference filter 10 and the light are compared with the case where only the adhesive member 5 is interposed between the bottom surface 101 of the Fabry-Perot interference filter 10 and the mounting surfaces 4a of the spacers 4A and 4B. It occurs in the Fabry-Perot interference filter 10 due to the difference in the coefficient of thermal expansion between other members (not only the spacers 4A and 4B, but also the wiring board 2, the stem 61, the cap 62, and the like) constituting the detection device 1A. The stress can be sufficiently absorbed by the adhesive member 5. Further, for example, the Fabry-Perot interference filter 10 is more stable than 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 spacer 4A, 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. Note that the adhesive member 5 is smaller than the elastic modulus of the other members (not only the spacers 4A and 4B, but also the Fabry-Perot interference filter 10, the wiring board 2, the stem 61, the cap 62, etc.) that constitute 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 bonding member 5 decreases and as the amount (volume) of the bonding member 5 increases is described. First, since the second portion 5b is interposed between the mounting surface 4a of each spacer 4A, 4B and the bottom surface 101 of the Fabry-Perot interference filter 10, the Fabry-Perot interference filter 10 and the photodetector 1A are configured. 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 is absorbed, and as a result, the generation of stress in the Fabry-Perot interference filter 10 is suppressed. Next, as the amount of the first portion 5a disposed at the corners C1, C2, C3, C4, C5, C6 increases, the thermal stress generated in the CAN package 6 (stress generated from various areas and directions). (The amount of thermal stress absorbed by the adhesive member 5> the amount of thermal stress generated in the CAN package 6), so that 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, and C6 are formed in a fillet shape so as to climb up the side surface 102 of the Fabry-Perot interference filter 10, each spacer 4A , 4B, and the Fabry-Perot interference filter 10 is held not only between the mounting surface 4a and the bottom surface 101 of the Fabry-Perot interference filter 10 but also from outside the side surface 102. Therefore, the holding state of the Fabry-Perot interference filter 10 on the spacers 4A and 4B is stabilized. As described above, the configuration of the bonding member 5 in the photodetector 1A improves the temperature characteristic of the transmission wavelength in the Fabry-Perot interference filter 10, stabilizes the holding state of the Fabry-Perot interference filter 10 on the spacers 4A and 4B, Can be realized.

  In addition, 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, It is larger than the thickness of the second portion 5b in a 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 bonding 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 of the spacers 4A and 4B. Then, it is possible to more reliably achieve both improvement of the temperature characteristic of the transmission wavelength in the Fabry-Perot interference filter 10 and 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 with the entire width of the portion of the mounting surface 4a that protrudes outside the side surface 102.

  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 surfaces 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 bonding member 5. be able to. Further, 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.

  Further, in the photodetector 1A, the adhesive member 5 is disposed 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 attached to the side surface 102a. In contact. Similarly, the adhesive member 5 is disposed 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. Thus, 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 only at one position in a part of each corner C1 and C4. In comparison with the case, the adhesive member 5 absorbs the stress generated in the Fabry-Perot interference filter 10 evenly due to the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter 10 and the other members constituting the photodetector 1A. be able to.

  In particular, when the height H and the width W of the first portion 5a in the adhesive member 5 are uniform, the thermal stress generated in the CAN package 6 can be absorbed by the adhesive member 5 more uniformly. 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 surface 4a of each of the spacers 4A and 4B at a uniform thickness, and the Fabry-Perot interference filter 10 is mounted thereon. Then, the adhesive is thermally cured, for example. When the Fabry-Perot interference filter 10 is mounted, the adhesive existing between the mounting surface 4a of each spacer 4A, 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. Thickness. The adhesive existing in the corners C1, C2, C3, C4, C5, and C6 creeps up on the side surface 102 of the Fabry-Perot interference filter 10, and has a uniform height and width. Thus, the adhesive member 5 including the first portion 5a having the uniform height H and the uniform width W is formed.

  The Fabry-Perot interference filter 10 is mounted on the mounting surface 4a of each of the spacers 4A and 4B, and thereafter, for example, an adhesive containing a silicone resin material is applied to the corners C1, C2, C3, C4, C5, and C5. It may be applied in 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 surface 4a of each of the spacers 4A and 4B and the bottom surface 101 of the Fabry-Perot interference filter 10 are in contact. The adhesive enters into the gap, and the adhesive has a uniform thickness due to the weight of the Fabry-Perot interference filter 10. The adhesive existing in the corners C1, C2, C3, C4, C5, and C6 creeps up on the side surface 102 of the Fabry-Perot interference filter 10, and has a uniform height and width. Alternatively, an adhesive containing, for example, a silicone-based resin material is applied only to a region of the mounting surface 4a of each of the spacers 4A and 4B on which the bottom surface 101 of the Fabry-Perot interference filter 10 is mounted. The interference filter 10 is placed, and thereafter, the adhesive is thermally cured, for example, and then the adhesive containing, for example, a silicone-based resin material is uniformly distributed along the corners C1, C2, C3, C4, C5, and C6. After that, the adhesive may be thermally cured, for example. Also in this case, when the Fabry-Perot interference filter 10 is mounted, the adhesive existing between the mounting surface 4a of each of the spacers 4A and 4B and the bottom surface 101 of the Fabry-Perot interference filter 10 is removed. The weight of 10 results in a uniform thickness. The adhesive present at the corners C1, C2, C3, C4, C5, and C6 has a uniform height and width on the side surface 102 of the Fabry-Perot interference filter 10.

  In the photodetector 1A, the adhesive member 5 is disposed 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 disposed at a corner C4 formed by the side surface 102b of the Fabry-Perot interference filter 10 facing the side surface 102a across the light transmission region 11, and is in contact with the side surface 102b. Thereby, the Fabry-Perot interference filter 10 can be held on the spacers 4A and 4B in a more stable state.

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

  In the photodetector 1A, the adhesive members 5 disposed at the corners C1, C2, and C3 are continuous with each other, and cover the corners 103a and 103b of the Fabry-Perot interference filter 10 from outside. Similarly, the adhesive members 5 arranged at the corners C4, C5, and C6 are continuous with each other, and cover the corners 103c and 103d of the Fabry-Perot interference filter 10 from outside. Thus, the corners 103a, 103b, 103a, 103b, where stress generated in the Fabry-Perot interference filter 10 due to a difference in thermal expansion coefficient between the Fabry-Perot interference filter 10 and other members constituting the photodetector 1A are likely to concentrate. 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 (in particular, since the adhesive member 5 is not provided on the light transmission region 11), the following effects are obtained. Is played. That is, since the light transmitted through the Fabry-Perot interference filter 10 does not pass through the bonding member 5, it is not necessary to select the bonding member 5 having a high light transmittance, and the degree of freedom in selecting the bonding member 5 is improved. In addition, since the light transmitted through the Fabry-Perot interference filter 10 does not pass through the adhesive member 5, the light transmitted through the Fabry-Perot interference filter 10 reflects the optical characteristics (refractive index, transmittance, etc.) of the adhesive member 5 due to a change in ambient temperature. ) Are not affected. 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 a change in 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 the photodetector 1B is configured as an SMD (Surface Mount Device). The light detection device 1B includes an SMD package 7 containing a light detector 3, a temperature compensation element (not shown), and a 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 stacked 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. Thereby, a part of each surface of the first layer substrate 71, the second layer substrate 72, the third layer substrate 73, and the fourth layer substrate 74 is exposed to 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 are connected to the electrode pad 77 by the wiring provided on the first layer substrate 71 or by the wire 8 and the wiring provided on each of the substrates 71 and 72. Is electrically connected to

  The Fabry-Perot interference filter 10 is fixed to the exposed surface of the third layer substrate 73 by the 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 wires 8. I have. The terminals 12 and 13 of the Fabry-Perot interference filter 10 are electrically connected to the electrode pads 77 by wires 8 and wiring provided on the substrates 71, 72, 73 and 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 is more thermally It is preferred that the expansion coefficients are equal.

  As a material of the adhesive member 5 for adhering the Fabry-Perot interference filter 10 and the third layer substrate 73, a resin material having flexibility (for example, a resin material such as silicone, urethane, epoxy, acrylic, hybrid, etc.) Which 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 use 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 becomes less than 10 MPa, and the glass transition temperature becomes the use environment temperature (for example, about 5 to 40 ° C.). About -50 to -40 ° C.

  Here, the elasticity of the bonding member 5 that bonds the Fabry-Perot interference filter 10 and the third-layer substrate 73 is smaller than the elasticity of the third-layer substrate 73. Further, the elastic modulus of the bonding member 5 for bonding the Fabry-Perot interference filter 10 and the third layer substrate 73 is such that the first layer substrate 71, the second layer substrate 72, the third layer substrate 73, the fourth layer substrate 74, It is smaller than the elastic modulus of an adhesive member (not shown) for bonding the fifth layer substrate 75 and the sixth layer substrate 76 to each other. For example, an epoxy-based material is used as a material of an adhesive member that bonds 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. If an adhesive containing a resin material is used, the Young's modulus after curing becomes 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, or the like) 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-blocking layer 76b, a light-blocking material or a light-absorbing material (for example, a metal such as aluminum, a metal oxide such as chromium oxide, a black resin, or the like) can be used. An opening 76c is provided in the light shielding layer 76b. The light transmission region 11 and the opening 76c face each other in the direction A. Note that the light blocking layer 76b may be formed on the back surface of the light transmitting substrate 76a. Further, an anti-reflection 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 transmitting substrate 76a, a band pass 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 enters the light transmission region 11 of the Fabry-Perot interference filter 10 from the outside via the opening 76c and the light transmission substrate 76a, the first mirror in the light transmission region 11 Light having a predetermined wavelength is selectively transmitted according to 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 is detected by the photodetector 3. In the photodetector 1B, the first mirror 31 and the second mirror 41 are changed while changing the voltage applied to the Fabry-Perot interference filter 10 (that is, while changing the distance between the first mirror 31 and the second mirror 41). By detecting the transmitted light with the photodetector 3, a spectrum can be obtained.
[Configuration of Adhesive Member for Adhering 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. In FIG. 6, the sixth layer substrate 76 and the like are omitted.

  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 has a Fabry-Perot interference. A 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 disposed outside the side surface 102a (outside the side surface 102 when viewed from the direction A). Thus, 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 where the Fabry-Perot interference filter 10 is not mounted but is exposed). Among the side surfaces 102, one end of the side surface (fifth side surface) 102c that forms the corner portion 103a together with the side surface (fourth side surface) 102a on the corner 103a side has a part of the mounting surface 73a disposed outside the side surface 102c. So that it is located on the mounting surface 73a. Thereby, the corner C2 is formed between one end of the side surface 102c and a portion of the mounting surface 73a outside the one end of the side surface 102c (a portion where the Fabry-Perot interference filter 10 is not mounted and is exposed). Is formed. Of the side surfaces 102, one end of the side surface (fifth side surface) 102d that forms the corner portion 103b together with the side surface (fourth side surface) 102a on the corner 103b side has a part of the mounting surface 73a disposed outside the side surface 102d. So that it is located on the mounting surface 73a. Thereby, a corner C3 is formed between one end of the side surface 102d and a portion of the mounting surface 73a outside the one end of the side surface 102d (a portion where the Fabry-Perot interference filter 10 is not mounted and is exposed). Is formed. The above-described one end of the side surface 102a, the side surface 102c, and the one end of the side surface 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 such that a part of the mounting surface 73a is disposed outside the side surface 102b. Thus, 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 that forms the corner 103c together with the side surface (fourth side surface) 102b of the side surface 102 has a part of the mounting surface 73a disposed outside the side surface 102c. So that it is located on the mounting surface 73a. Thereby, a corner is formed between the other end of the side surface 102c and a portion of the mounting surface 73a outside the other end of the side surface 102c (a portion where the Fabry-Perot interference filter 10 is not mounted and is exposed). A portion C5 is formed. The other end of the side surface (fifth side surface) 102d that forms the corner portion 103d together with the side surface (fourth side surface) 102b of the side surface 102 has a part of the mounting surface 73a disposed outside the side surface 102d. So that it is located on the mounting surface 73a. Thus, the other end of the side surface 102d and a portion of the mounting surface 73a outside the other end of the side surface 102d (a portion where the Fabry-Perot interference filter 10 is not mounted but is exposed) are formed at the corners. A portion C6 is formed. The other ends of the side surfaces 102b and 102c and the other end of the side surface 102d correspond to a part of an outer edge of the Fabry-Perot interference filter 10 when viewed from the direction A.

  The bonding 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 members 5 arranged at the corners C1, C2, C3 are continuous over the entire corner C1, and cover the corners 103a, 103b from 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 members 5 disposed at the corners C4, C5, and C6 are continuous over the entire corner C4, and cover the corners 103c and 103d from outside.

  The adhesive member 5 disposed at each corner C1, C2, C3 includes a first portion 5a and a second portion 5b. The first portion 5a is a portion disposed along each of the corners C1, C2, and C3, and is continuous via each of the corners 103a and 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. At 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. At 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. At 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. That is, the adhesive members 5 disposed at the corners C1, C2, and 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 disposed at each of the corners C4, C5, and C6 includes a first portion 5a and a second portion 5b. The first portion 5a is a portion disposed along each of the corners C4, C5, and C6, and is continuous via each of the corners 103c and 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. At the corner C4, the first portion 5a is in contact with each of the side surface 102b, the mounting surface 73a, and the inner surface 74a of the opening of the fourth layer substrate 74. At 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. At 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, and 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, and C3, the edge 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 disposed at the corners C1, C2, and C3 are in contact with the substrate 14 at the side surfaces 102. Similarly, in each of the corners C4, C5, and C6, the edge 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 disposed at the corners C4, C5, and C6 are in contact with the substrate 14 on the side surfaces 102. The height of the edge 5c is lower than the heights 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 (Corresponding to 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 the elastic modulus of the third-layer substrate 73 is disposed at the corners C1, C2, C3, C4, C5, and C6, and serves as a Fabry-Perot interference filter. The side surface 102 and a part of the mounting surface 73 a of the third layer substrate 73 are in contact with each other. Thus, for example, the Fabry-Perot interference filter 10 and the light are compared with the case where the adhesive member 5 is merely interposed between the bottom surface 101 of the Fabry-Perot interference filter 10 and the mounting surface 73a of the third layer substrate 73. 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 adhesive member 5 can sufficiently absorb the stress generated in the Fabry-Perot interference filter 10 due to the difference in thermal expansion coefficient between the adhesive member 5. Further, for example, the Fabry-Perot interference filter 10 is more stable than when 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, 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 third layer substrate 73 is stabilized. Can be. Note that the adhesive member 5 is made up of other members constituting the photodetector 1B (not only the third layer substrate 73, 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 the mounting value. It is larger than the thickness of the second portion 5b in a direction perpendicular to the surface 73a. 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 1B is more sufficiently absorbed by the bonding 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, the improvement of the temperature characteristic 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 can be more reliably achieved. Therefore, it is preferable that the adhesive member 5 is in contact with the entire width of the portion of the mounting surface 73a that protrudes outside the side surface 102.

  In the photodetector 1B, 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 surfaces 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 1B is more sufficiently absorbed by the bonding member 5. be able to. Further, 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.

  Further, in the photodetector 1B, the adhesive member 5 is disposed 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 attached to the side surface 102a. In contact. Similarly, the adhesive member 5 is disposed 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. Thus, 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 only at one position in a part of each corner C1 and C4. In comparison with the case, the adhesive member 5 absorbs the stress generated in the Fabry-Perot interference filter 10 more uniformly 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 the photodetector 1B, the adhesive member 5 is disposed 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 disposed at a corner C4 formed by the side surface 102b of the Fabry-Perot interference filter 10 facing the side surface 102a across the light transmission region 11, and is in contact with the side surface 102b. Thus, 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 disposed at the corners C1, C2, and C3 are continuous with each other, and cover the corners 103a and 103b of the Fabry-Perot interference filter 10 from outside. Similarly, the adhesive members 5 arranged at the corners C4, C5, and C6 are continuous with each other, and cover the corners 103c and 103d of the Fabry-Perot interference filter 10 from outside. Thereby, the corners 103a, 103b, 103a, 103b, where stress generated in the Fabry-Perot interference filter 10 due to a difference in thermal expansion coefficient between the Fabry-Perot interference filter 10 and other members constituting the photodetector 1B tend to concentrate. In 103c and 103d, the stress can be sufficiently absorbed by the adhesive member 5.

  Further, in the light detection device 1B, since the adhesive member 5 is not provided on the entire bottom surface 101 of the Fabry-Perot interference filter 10 (in particular, since the adhesive member 5 is not provided on the light transmission region 11), the following effects are obtained. Is played. That is, since the light transmitted through the Fabry-Perot interference filter 10 does not pass through the bonding member 5, it is not necessary to select the bonding member 5 having a high light transmittance, and the degree of freedom in selecting the bonding member 5 is improved. In addition, since the light transmitted through the Fabry-Perot interference filter 10 does not pass through the adhesive member 5, the light transmitted through the Fabry-Perot interference filter 10 reflects the optical characteristics (refractive index, transmittance, etc.) of the adhesive member 5 due to a change in ambient temperature. ) Are not affected. 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.

  In the photodetector 1B, a horizontally long space (a space whose width in the direction perpendicular to the direction A is larger than the width in the direction parallel to the direction A) is provided on both sides of the Fabry-Perot interference filter in the direction A. In the photodetector 1B, when viewed from the direction A, the outer edge of the space provided on both sides of the Fabry-Perot interference filter in the direction A is defined by the inner edge of the SMD package 7. 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 emission 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 more parallel to the direction A than the space provided on the light incidence side of the Fabry-Perot interference filter 10. Is large. Further, in the photodetector 1B, the Fabry-Perot interference filter 10 is electrically connected to a plurality of electrode pads 77 provided on the bottom surface of the SMD package 7 via wiring provided on the SMD package 7.

  As described above, the size of the photodetector 1B can be reduced. Further, by providing a horizontally long space 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 reduced compared to the case where a vertically long space is provided. In addition, the distance between the Fabry-Perot interference filter 10 and the photodetector 3 can be reduced. Therefore, even if light enters the opening 76c slightly obliquely, 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. Can be. Further, by providing a horizontally long space on both sides of the Fabry-Perot interference filter in the direction A, the height of the members constituting the SMD package 7 is reduced as compared with the case where a vertically long space is provided, and the SMD package 7 Can be kept small. Therefore, it is possible to suppress the generation of stress due to the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter 10 and the SMD package 7.

  As described above, the first and second embodiments of the present invention have been described, but the present invention is not limited to the above-described first and second embodiments. For example, in the first embodiment, the bonding member 5 includes the second portion 5b disposed between the mounting surface 4a of the spacer 4A and the bottom surface 101 of the Fabry-Perot interference filter 10, but the bonding member 5 is If the first part 5a is included, the second part 5b need not be included. Similarly, in the second embodiment, the adhesive member 5 includes the second portion 5b disposed between the mounting surface 73a of the third layer substrate 73 and the bottom surface 101 of the Fabry-Perot interference filter 10, but The bonding member 5 need not include the second portion 5b as long as the bonding member 5 includes the first portion 5a. If the bonding 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 materials and shapes of the respective components are not limited to the materials and shapes described above, and various materials and shapes can be adopted.

  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. As shown in (1), the bottom surface 101 of the Fabry-Perot interference filter 10 may be mounted on the mounting surface 70a of a support (support) 70 corresponding to a substrate integrally formed with the substrates. In this case, the formed SMD package is compared with a 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 and bonded to each other. There is little variation in the shape of each 7. In addition, 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 peripheral A change in the shape of the SMD package 7 due to expansion and contraction of the adhesive member due to a change in temperature is suppressed. Further, since moisture contained in the outside air can be prevented from entering the inside of the SMD package 7 through the adhesive member 5, the adhesive member 5 between the Fabry-Perot interference filter 10 and the SMD package 7 is affected by moisture. Can be prevented from deteriorating. Therefore, in this case, a more stable SMD package 7 can be obtained.

  In the first and second embodiments, the edge 5c of the adhesive member 5 reaches the side surface of the substrate 14 of the Fabry-Perot interference filter 10, but the edge 5c of the adhesive member 5 does not reach the side surface of the substrate 14. , The side surface of the laminate 50 of the Fabry-Perot interference filter 10. That is, the adhesive member 5 may be in contact with the side surface of the multilayer body 50 without contacting the side surface of the substrate 14.

  1A, 1B: photodetector, 3: photodetector, 4, 4A, 4B: spacer (supporting member), 4a: mounting surface, 5: adhesive member, 5a: first portion, 5b: second portion, 10 ... Fabry-Perot interference filter, 11 ... light transmission area, 14 ... substrate, 31 ... first mirror, 41 ... second mirror, 70 ... support (supporting 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 surfaces (fifth side surface), C1, C2, C3, C4, C5, C6 ... corner portions.

Claims (8)

A Fabry-Perot interference filter having a first mirror and a second mirror whose distance is variable, and having a light transmission area for transmitting light according to the distance between the first mirror and the second mirror;
A light detector for detecting light transmitted through the light transmitting region,
A package containing the Fabry-Perot interference filter and the photodetector,
The package is
A support for supporting the Fabry-Perot interference filter and the photodetector,
A light transmitting substrate that transmits light incident on the light transmitting region,
A first space on a light incident side of the Fabry-Perot interference filter in a direction in which light passes through the light transmitting region, and the Fabry-Perot interference filter in a direction in which light passes through the light transmitting region; A second space on the light emission side of
In each of the first space and the second space, a width in a direction perpendicular to the direction in which light passes through the light transmitting region is greater than a width in a direction parallel to the direction in which light passes through the light transmitting region. A photodetector that is also a large space.   The photodetector according to claim 1, wherein the photodetector is disposed in the second space.   3. The light detection device according to claim 1, wherein the first space has a larger width in a direction perpendicular to the direction in which light passes through the light transmitting region than the second space. 4. The package is
4. The light-transmitting substrate according to claim 1, further comprising: a light-shielding layer provided on the light-transmitting substrate, the light-transmitting region being provided with an opening facing the light-transmitting region in the direction in which light passes through the light-transmitting region. Photodetector. Further comprising an adhesive member for adhering the Fabry-Perot interference filter and the support,
The photodetector according to claim 1, wherein an elastic modulus of the adhesive member is smaller than an elastic modulus of the support. An electrode pad is provided on the bottom surface of the support,
The photodetector according to any one of claims 1 to 5, wherein the Fabry-Perot interference filter is electrically connected to the electrode pad via a wiring provided on the support. The support is configured by stacking a plurality of substrates,
The plurality of substrates,
A first substrate having a first opening formed therein;
A second substrate having a second opening formed thereon, the second substrate being stacked on the first substrate on the light transmitting substrate side,
The second opening includes the first opening when the light transmission region is viewed from the direction in which light transmits.
A region of the first substrate on the light transmitting substrate side, which is exposed to the second opening, is a mounting surface on which a portion of the bottom surface of the Fabry-Perot interference filter outside the light transmitting region is mounted. The photodetector according to any one of claims 1 to 6.   The photodetector according to any one of claims 1 to 6, wherein the support is formed integrally.

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