JP7049296B2 - Photodetector - Google Patents

Description

The present invention relates to an optical detection device including a Fabry-Perot interference filter having a first mirror and a second mirror having a variable distance.

Patent Document 1 describes an interference filter having a first reflective film and a second reflective film having a variable distance, a substrate supporting the interference filter, and an adhesive layer interposed between the interference filter and the substrate. An optical module with, is described. In the optical module described in Patent Document 1, a gel-like resin is used for the adhesive layer in order to alleviate the stress generated in the interference filter due to the difference in the coefficient of thermal expansion between the interference filter and the substrate.

Japanese Unexamined Patent Publication No. 2012-173347

However, when fixing the Fabry-Pérot interference filter having the first and second mirrors having variable distances to the support member, it is necessary to control the distance between the first mirror and the second mirror with extremely high accuracy. Therefore, simply interposing an adhesive layer made of gel-like resin between the Fabry-Pérot interference filter and the support member is sufficient to sufficiently change the stress generated in the Fabry-Pérot interference filter due to changes in the operating environment temperature and the like. It cannot be suppressed, and as a result, the temperature characteristics of the transmission wavelength of the Fabry-Perot interference filter (the temperature characteristics 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-like resin is used for fixing the Fabry-Pérot interference filter and the support member, the holding state of the Fabry-Pérot interference filter on the support member may become unstable.

Therefore, the present invention provides an optical detection device capable of sufficiently improving the temperature characteristics of the transmission wavelength of the Fabry-Pérot interference filter and stabilizing the holding state of the Fabry-Pérot interference filter on the support member. With the goal.

The light detection device of the present invention has a first mirror and a second mirror having a variable distance, and has a 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 light detector that detects light transmitted through the light transmission region, a support member having a mounting surface on which the outer portion of the bottom surface of the Fabry-Perot interference filter is mounted, and Fabry-Perot interference. It comprises an adhesive member for adhering the filter and the support member, the elastic coefficient of the adhesive member is smaller than the elastic coefficient of the support member, and at least a part of the side surface of the Fabry-Perot interference filter is a part of the mounting surface. Located on the mounting surface so that it is located on the outside of the side surface, the adhesive member is located on the side surface and in the corners formed by a portion of the mounting surface, on the side surface and on the mounting surface. It is in contact with some of them.

In this optical detection device, an adhesive member having an elastic modulus smaller than the elastic modulus of the support member is arranged on the side surface of the Fabry-Perot interference filter and 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. This results in a thermal expansion coefficient between the Fabry-Pérot interference filter and the support member, as compared to, for example, the case where the adhesive member is merely interposed between the bottom surface of the Fabry-Pérot interference filter and the mounting surface of the support member. The stress generated in the Fabry-Perot interference filter due to the difference between the two can be sufficiently absorbed by the adhesive member. Further, for example, compared to the case where the adhesive member is merely interposed between the bottom surface of the Fabry-Pérot interference filter and the mounting surface of the support member, the Fabry-Pérot interference filter can be placed on the support member more firmly in a stable state. Can be held in. Therefore, according to this light detection device, 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 light detection device of the present invention, the adhesive member includes a first portion arranged at a corner and a second portion arranged between the mounting surface and the bottom surface, and is in a 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 the above may be larger than the thickness of the second portion. As a result, the stress generated in the Fabric Perot interference filter due to the difference in the coefficient of thermal expansion between the Fabric Perot interference filter and the support member can be more sufficiently absorbed by the adhesive member.

In the light detection device of the present invention, the Fabry-Perot interference filter further includes 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. .. As a result, the stress generated in the Fabric Perot interference filter due to the difference in the coefficient of thermal expansion between the Fabric Perot interference filter and the support 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 connected to the corner portion 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. This is due to, for example, the difference in the coefficient of thermal expansion between the Fabry-Perot interference filter and the support member as compared with the case where a plurality of adhesive members are intermittently arranged in the corner formed by the first side surface. 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 surfaces include a second side surface and a third side surface facing each other across a light transmitting region, and the adhesive member is formed by a corner formed by the second side surface and a third side surface. It may be arranged in each of the corners and is in contact with each of the second side surface and the third side surface. As a result, 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 portion, and the adhesive member is a corner portion formed by the fourth side surface and a corner portion formed by the fifth side surface. It may be arranged in each of the above and may be in contact with each of the fourth side surface and the fifth side surface. As a result, the stress can be sufficiently absorbed by the adhesive member at the corner where the stress generated in the Fabric Perot interference filter due to the difference in the coefficient of thermal expansion between the Fabric Perot interference filter and the support member is likely to be concentrated. 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. .. As a result, the stress is more sufficiently absorbed by the adhesive member at the corner where the stress generated in the Fabric Perot interference filter due to the difference in the coefficient of thermal expansion between the Fabric Perot interference filter and the support member is likely to be concentrated. Can be done.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an optical detection device capable of sufficiently improving the temperature characteristics of the transmission wavelength of the Fabry-Pérot interference filter and stabilizing the holding state of the Fabry-Pérot interference filter on the support member. Is possible.

It is sectional drawing of the photodetector of 1st Embodiment. It is sectional drawing of the Fabry-Perot interference filter of the photodetector of FIG. FIG. 3 is a plan view of a portion of the photodetector of FIG. 1 including a Fabry-Perot interference filter, a spacer, and an adhesive member. FIG. 3 is a cross-sectional view of a portion of the optical detection device of FIG. 1 including a Fabry-Perot interference filter, a spacer, and an adhesive member. It is sectional drawing of the photodetector of 2nd Embodiment. FIG. 5 is a plan view of a portion of the photodetector of FIG. 5 including a Fabry-Perot interference filter, a third layer substrate, and an adhesive member. It is sectional drawing of the modification of the light 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 1A includes a wiring substrate 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 having variable distances. The photodetector 1A is a spectroscopic sensor capable of obtaining 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, it 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 light transmitted through the light transmission region 11 of the Fabry-Perot interference filter 10 is detected by the light detector 3.

A temperature compensation element (not shown) such as a photodetector 3 and a thermistor is mounted on the wiring board 2. As the substrate material of the wiring board 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 through which light is transmitted 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 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 each wavelength range of ultraviolet, visible, and near-infrared, for example, a silicon photodiode or the like can be used as the photodetector 3. Further, the photodetector 3 may be provided with one light receiving unit 3a, or may be provided with a plurality of light receiving units 3a 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 a 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 a plurality of spacers 4. As the 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 fabric perlow interference filter 10 and each spacer 4, the material of each spacer 4 has the same coefficient of thermal expansion as that of the material of the fabric perot interference filter 10. Is preferable. 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 a plurality of spacers 4.

The material of the adhesive member 5 for adhering the fabric perow interference filter 10 and each spacer 4 is a flexible resin material (for example, a resin material such as silicone-based, urethane-based, epoxy-based, acrylic-based, or hybrid). It 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 from materials whose glass transition temperature deviates from 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.). It will be about -50 to -40 ° C, which is lower than that.

Here, the elastic modulus of the adhesive member 5 for adhering the fabric perow interference filter 10 and each spacer 4 is smaller than the elastic modulus of the spacer 4. Further, the elastic modulus of the adhesive member 5 that adheres the fabric perow interference filter 10 and each spacer 4 is smaller than the elastic modulus of the adhesive member (not shown) that adheres the wiring substrate 2 and each spacer 4. For example, if an adhesive containing an epoxy-based resin material is used as the material of the adhesive member for adhering the wiring substrate 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 with respect to tensile / compressive stress), transverse elastic modulus (relationship with strain with shear stress), and volume elastic modulus (pressure and volume strain under uniform compression). (Relationship with) is a general term. That is, Young's modulus is a specific example of elastic modulus.

The photodetector 1A further includes a CAN package 6. The CAN package 6 houses the wiring substrate 2, the photodetector 3, a temperature compensation element (not shown), a plurality of spacers 4, a plurality of adhesive members 5, and a Fabry-Perot interference filter 10 described above. The CAN package 6 has a stem 61 and a cap 62. The cap 62 is provided with an opening 62a, 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 the material of the light transmitting member 63, a material corresponding to the measurement wavelength range of the light detection device 1A (for example, glass, silicon, germanium, etc.) 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 pad provided on the wiring board 2, the terminal of the photodetector 3, the terminal of the temperature compensating element, and the terminals 12 and 13 of the Fabry-Perot interference filter 10 are each of the plurality of lead pins 9 penetrating the stem 61. And wire 8 are electrically connected to each other. This enables input / output of electric signals to each of the photodetector 3, the temperature compensation element, and the Fabry-Perot interference filter 10. In the photodetector 1A, since the spacer 4 is arranged directly under 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 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 Light having a predetermined wavelength is selectively transmitted according to the distance between the 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 unit 3a of the photodetector 3 and is detected by the photodetector 3. In the optical detection device 1A, the first mirror 31 and the second mirror 41 are moved 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). A spectroscopic spectrum can be obtained by detecting the transmitted light with the light detector 3.
[Fabry-Pérot Interference Filter Configuration]

As shown in FIG. 2, the Fabry-Perot interference filter 10 includes a substrate 14. The antireflection layer 15, the first laminated body 30, the sacrificial layer 16 and the second laminated body 40 are laminated in this order on the surface 14a on the light incident side of the substrate 14. A gap (air gap) S is formed between the first laminated body 30 and the second laminated body 40 by the frame-shaped sacrificial layer 16. In the Fabry-Perot interference filter 10, light is incident on the second laminated body 40 from the opposite side of the substrate 14. Then, the light having a 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 center transmission wavelength (that is, the center wavelength in the wavelength range that the Fabry-Perot interference filter 10 can transmit).

The portion of the first laminated body 30 corresponding to the light transmitting region 11 functions as the first mirror 31. The first laminated body 30 is configured by alternately laminating 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 constituting the first mirror 31 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.

The portion of the second laminated body 40 corresponding to the light transmission region 11 functions as a second mirror 41 facing the first mirror 31 via the gap S. Similar to the first laminated body 30, the second laminated body 40 is configured by alternately laminating 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 constituting 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 of the second laminated body 40 corresponding to the void S, a plurality of through holes 40b extending from the surface 40a of the second laminated body 40 to the void S are provided so as to be uniformly distributed. The plurality of through holes 40b are formed to such an extent that they do not substantially affect the function of the second mirror 41. The inner diameter of each through hole 40b is 100 nm to 5 μm. Further, 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.

A first electrode 17 is formed on the first mirror 31 so as to surround the light transmission region 11. Further, the first mirror 31 is formed with a second electrode 18 so as to include a 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 transmitting region 11, but may be substantially the same as the size of the light transmitting region 11.

A 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 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 from the surface 40a of the second laminated body 40 to the first laminated 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. Further, the third electrode 19 is also electrically connected to the second electrode 18 via the wiring 23.

Trench 26, 27 are provided on the surface 30a of the first laminated body 30. The trench 26 extends in an annular shape 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. The trench 27 extends in an annular shape along the inner edge of the first electrode 17. The trench 27 electrically insulates the first electrode 17 from the inner region of the first electrode 17. The region in each of the trenches 26, 27 may be an insulating material or a void.

A trench 28 is provided on the surface 40a of the second laminated body 40. The trench 28 extends in an annular shape 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 and the third electrode 19. The region in the trench 28 may be an insulating material or a void.

The antireflection layer 51, the third laminated body 52, the intermediate layer 53, and the fourth laminated body 54 are laminated 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 laminated body 52 and the fourth laminated body 54 have a laminated structure symmetrical with the first laminated body 30 and the second laminated body 40 with respect to the substrate 14, respectively. The laminated body 50 is composed of the antireflection layer 51, the third laminated body 52, the intermediate layer 53, and the fourth laminated body 54. The laminated body 50 is arranged on the light emitting side of the substrate 14 and has a function of suppressing the warp of the substrate 14.

The laminated body 50 is formed with, for example, a columnar opening 50a so as to include the light transmitting region 11. The opening 50a is open to 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 of the laminated body 50 on the light emitting side. 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 applied. 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 drive, the distance between the first mirror 31 and the second mirror 41 is adjusted. The wavelength of light transmitted 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 compensating electrode for keeping the first mirror 31 and the second mirror 41 flat in the light transmission region 11.
[Structure of adhesive member that adheres 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, in FIG. 3, the wire 8, the stem 61, and the like are omitted, and in FIG. 4, the wiring board 2, the wire 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, 4B. On the mounting surface 4a of the spacer 4A, a portion of the bottom surface 101 of the Fabry-Perot interference filter 10 that is outside the light transmission region 11 and is 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 that is outside the light transmission region 11 and is 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. Of the side surfaces 102, the side surfaces (first side surface, second side surface) 102a and the side surface (first side surface, third side surface) 102b face 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 on the outside of the side surface 102a (outside of the side surface 102 when viewed from the direction A). ing. As a result, the corner portion C1 is formed by the side surface 102a and the outer portion of the mounting surface 4a of the spacer 4A (the portion where the Fabry-Perot interference filter 10 is not mounted and is exposed). ing. Of the side surface 102, a part of the mounting surface 4a of the spacer 4A is outside the side surface 102c at one end of the side surface (fifth side surface) 102c on the corner portion 103a side forming the corner portion 103a together with the side surface (fourth side surface) 102a. It is located on the mounting surface 4a of the spacer 4A so as to be arranged in. As a result, one end of the side surface 102c and the outer portion of the mounting surface 4a of the spacer 4A outside the one end of the side surface 102c (the portion exposed without the Fabry-Perot interference filter 10 being mounted). The corner C2 is formed. Of the side surface 102, a part of the mounting surface 4a of the spacer 4A is outside the side surface 102d at one end of the side surface (fifth side surface) 102d forming the corner portion 103b together with the side surface (fourth side surface) 102a. It is located on the mounting surface 4a of the spacer 4A so as to be arranged in. As a result, one end of the side surface 102d and the outer portion of the mounting surface 4a of the spacer 4A outside the one end of the side surface 102d (the portion exposed without the Fabry-Perot interference filter 10 being mounted). The corner C3 is formed. The above-mentioned side surface 102a, one end of the side surface 102c, and 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 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 portion C4 is formed by the side surface 102b and the outer portion of the mounting surface 4a of the spacer 4B (the portion where the Fabry-Perot interference filter 10 is not mounted and is exposed). ing. Of the side surface 102, a part of the mounting surface 4a of the spacer 4B is part of the side surface 102c at the other end of the side surface (fifth side surface) 102c on the corner portion 103c side forming the corner portion 103c together with the side surface (fourth side surface) 102b. It is located on the mounting surface 4a of the spacer 4B so as to be arranged on the outside. As a result, the other end of the side surface 102c and the outer portion of the mounting surface 4a of the spacer 4B outside the other end of the side surface 102c (the exposed portion where the Fabry-Perot interference filter 10 is not mounted). The corner C5 is formed. Of the side surface 102, a part of the mounting surface 4a of the spacer 4B is part of the side surface 102d at the other end of the side surface (fifth side surface) 102d on the corner portion 103d side forming the corner portion 103d together with the side surface (fourth side surface) 102b. It is located on the mounting surface 4a of the spacer 4B so as to be arranged on the outside. As a result, the other end of the side surface 102d and the outer portion of the mounting surface 4a of the spacer 4B outside the other end of the side surface 102d (the exposed portion where the Fabry-Perot interference filter 10 is not mounted). The corner C6 is formed. The other end of the side surface 102b, the other end of the side surface 102c, and the other 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.

On the mounting surface 4a of the spacer 4A, the adhesive member 5 is arranged at each corner portion C1, C2, C3, and the adhesive member 5 arranged at each corner portion C1, C2, C3 is 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 portion C1 and covers the corner portions 103a and 103b from the outside.

On the mounting surface 4a of the spacer 4B, the adhesive member 5 is arranged at each corner portion C4, C5, C6, and the adhesive member 5 arranged at each corner portion C4, C5, C6 is 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 portion C4 and covers the corner portions 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 the respective corner portions C1, C2, and C3, and is continuous via the respective corner portions 103a and 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. In the corner portion 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 portion 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 the side surface 102 and the mounting surface 4a of the spacer 4A, respectively.

Similarly, the adhesive member 5 arranged on the mounting surface 4a of the spacer 4B includes the first portion 5a and the second portion 5b. The first portion 5a is a portion arranged along each corner portion C4, C5, C6, and is continuous via the respective corner portions 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. In 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. In the corner portion 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. In the corner portion 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 the side surface 102 and the mounting surface 4a of the spacer 4B, respectively.

In each of the corners C1, C2, and C3, the highest edge portion 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 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 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 of the spacers 4A and 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 set. Each is 10 to 1000 μm. 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 projecting 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-Pérot 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. Therefore, if the height H of the first portion 5a is 10 μm or more, it is the first. The highest edge portion 5c of one portion 5a can be brought to 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 (fabripelling 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 light detection device 1A, the adhesive member 5 having an elastic modulus smaller than the elastic modulus of each of the spacers 4A and 4B is arranged at the corners C1, C2, C3, C4, C5 and C6, and is a fabric perow interference filter. 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. As a result, for example, the Fabry-Pérot 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-Pérot interference filter 10 and the mounting surface 4a of the spacers 4A and 4B. It occurs in the Fabry-Perot interference filter 10 due to the difference in the thermal expansion coefficient with other members (not only the spacers 4A and 4B but also the wiring board 2, the stem 61, the cap 62, etc.) constituting the detection device 1A. The stress can be sufficiently absorbed by the adhesive member 5. Further, for example, the Fabry-Pérot interference filter 10 is more stable than 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 4a of the spacers 4A and 4B. It can be more firmly held on the spacers 4A and 4B in the state. Therefore, according to the light detection device 1A, the temperature characteristic of the transmission wavelength in the Fabry-Perot interference filter 10 can be sufficiently improved, and the holding state of the Fabry-Pérot interference filter 10 on the spacers 4A and 4B can be stabilized. 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 board 2, the stem 61, the cap 62, etc.) constituting the light detection device 1A. It is preferable to have 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 increases will be described. First, the Fabry-Perot interference filter 10 and the optical detection device 1A are configured by interposing the second portion 5b between the mounting surface 4a of the spacers 4A and 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 thermal expansion coefficient with the 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 arranged in the corners C1, C2, C3, C4, C5, and C6 increases, the thermal stress generated in the CAN package 6 (stress generated from various areas and directions). (Amount of heat stress absorbed by the adhesive member 5> amount of heat stress generated in the CAN package 6), so that the temperature characteristic of the transmission wavelength in the fabric perow interference filter 10 is improved.

Further, since the first portion 5a arranged at the corners C1, C2, C3, C4, C5, and C6 is formed in a fillet shape so as to crawl up the side surface 102 of the Fabry-Perot interference filter 10, each spacer 4A The Fabry-Pérot interference filter 10 is held not only between the mounting surface 4a of 4B and the bottom surface 101 of the Fabry-Pérot interference filter 10 but also 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 is stable. As described above, the configuration of the adhesive member 5 in the light detection device 1A includes 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-Pérot 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 the mounting value. It is larger than the thickness of the second portion 5b in the direction perpendicular to the surface 4a. 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 constituting the light detection device 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 of the spacers 4A and 4B. Then, it is possible to more reliably realize both the improvement of the temperature characteristic of the transmission wavelength of 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 with the mounting surface 4a over the entire width of the portion of the mounting surface 4a that overhangs the outside of the side surface 102.

Further, in the light detection device 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 fabric perlow interference filter 10. 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 constituting the light detection device 1A is more sufficiently absorbed by the adhesive 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 more stabilized.

Further, in the photodetector 1A, the adhesive member 5 is arranged on the corner portion C1 so as to be continuous over the entire corner portion C1 formed by the side surface 102a of the Fabry-Perot interference filter 10, and is arranged 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 a plurality of adhesive members 5 are intermittently arranged in each corner C1 and C4, or the adhesive member 5 is arranged only in one place in a part of each corner C1 and C4. Compared with the case, the stress generated in the fabric perow interfering filter 10 due to the difference in the coefficient of thermal expansion between the fabric perow interfering filter 10 and the other members constituting the optical detection device 1A is uniformly absorbed by the adhesive member 5. be able to.

In particular, when 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 fabric perow interference filter 10 is mounted on the adhesive in that state. , The adhesive is, for example, thermoset. When the Fabry-Pérot interference filter 10 is mounted, the adhesive existing between the mounting surface 4a of the spacers 4A and 4B and the bottom surface 101 of the Fabry-Pérot interference filter 10 is uniform due to the weight of the Fabry-Pérot interference filter 10. It will be thick. Further, the adhesive present at the corners C1, C2, C3, C4, C5, and C6 crawls up the side surface 102 of the fabric perow 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 Fabric Perot interference filter 10 is placed on the mounting surface 4a of each of the spacers 4A and 4B, and then an adhesive containing, for example, a silicone-based resin material is applied to the corners C1, C2, C3, C4, C5. It may be applied in a uniform thickness along C6 and then the adhesive may be thermoset, for example. Also in this case, when the adhesive is applied along the corners C1, C2, C3, C4, C5, C6, the mounting surface 4a of each of the spacers 4A and 4B and the bottom surface 101 of the fabric perow interference filter 10 An adhesive gets in between, and the adhesive has a uniform thickness due to the weight of the Fabric Perot interference filter 10. Further, the adhesive present at the corners C1, C2, C3, C4, C5, and C6 crawls up the side surface 102 of the fabric perow interference filter 10 to have a uniform height and width. Alternatively, an adhesive containing, for example, a silicone-based resin material is applied only to the region of the mounting surfaces 4a of the spacers 4A and 4B on which the bottom surface 101 of the fabric perlow interference filter 10 is mounted, and then the fabric perow is applied. The interference filter 10 is placed, after which the adhesive is, for example, thermoset, and then the adhesive containing, for example, a silicone-based resin material is uniformly applied along the corners C1, C2, C3, C4, C5, C6. The adhesive may be applied to a certain thickness and then the adhesive may be heat-cured, for example. Also in this case, when the Fabry-Pérot interference filter 10 is mounted, the adhesive existing between the mounting surface 4a of the spacers 4A and 4B and the bottom surface 101 of the Fabry-Pérot interference filter 10 is the Fabry-Pérot interference filter. The weight of 10 makes the thickness uniform. Further, the adhesives present in the corners C1, C2, C3, C4, C5, and C6 have a uniform height and width on the side surface 102 of the fabric perow interference filter 10.

Further, in the photodetector 1A, the adhesive member 5 is arranged at the corner portion 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. As a result, 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 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 Even if the adhesive member 5 is arranged in each of the corners C1 and C4 formed by each, it is suppressed that the fabric perow interference filter 10 is distorted by the thermal stress generated in the CAN package 6, but rather the CAN. The thermal stress generated in the package 6 is absorbed by the adhesive member 5.

Further, in the light detection device 1A, the adhesive members 5 arranged 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 the 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 the outside. As a result, the corner portions 103a, 103b, in which 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 optical detection device 1A is likely to be concentrated. In 103c and 103d, the stress can be sufficiently absorbed by the adhesive member 5.

Further, in the light detection device 1A, since the adhesive member 5 is not provided on the entire bottom surface 101 of the Fabry-Perot interference filter 10 (particularly, 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 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 has the optical characteristics (refractive index, transmittance, etc.) of the adhesive member 5 due to the change in the ambient temperature. ) Is not affected by the change. Further, the Fabry-Perot interference filter 10 is distorted or tilted due to the shrinkage of the adhesive member 5 during curing and the stress generated by the expansion and contraction of the adhesive member 5 due to the change in ambient temperature during use. Is suppressed.
[Second Embodiment]
[Configuration of photodetector]

As shown in FIG. 5, the photodetector 1B is different from the above-mentioned photodetector 1A in that it is configured as an SMD (Surface Mount Device). The photodetector 1B includes a photodetector 3, a temperature compensating element (not shown), and an SMD package 7 containing 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 laminated in this order. An opening is provided in the central portion 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 to the opening of the fifth layer substrate 75.

A photodetector 3 and a temperature compensating element (not shown) are mounted on the surface of the exposed 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 wiring provided on the wire 8 and the substrates 71 and 72. Is electrically connected to.

A Fabry-Perot interference filter 10 is fixed to the surface of the exposed 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. A pad electrically connected to the electrode pad 77 is provided on the upper surface of the fourth layer substrate 74, and the terminals 12 and 13 are connected to the pad on the upper surface of the fourth layer substrate 74 by a wire 8. There is. The terminals 12 and 13 of the Fabry-Perot interference filter 10 are electrically connected to the electrode pad 77 by the wires provided on the wires 8 and the substrates 71, 72, 73 and 74. The third layer substrate 73 functions as a support member for supporting the Fabry-Perot interference filter 10 on the first layer substrate 71 and the second layer substrate 72.

As the 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, ceramics, resins, and the like can be used. In particular, in order to alleviate the difference in the coefficient of thermal expansion between the Fabric Perot Interference Filter 10 and the Third Layer Substrate 73, the material of the third layer substrate 73 is thermally compared to the material of the Fabric Perot Interference Filter 10. It is preferable that the expansion coefficients are the same.

The material of the adhesive member 5 for adhering the fabric perow interference filter 10 and the third layer substrate 73 is a flexible resin material (for example, a resin material such as silicone-based, urethane-based, epoxy-based, acrylic-based, or hybrid). (It 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 from materials whose glass transition temperature deviates from 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.). It will be about -50 to -40 ° C, which is lower than that.

Here, the elastic modulus of the adhesive member 5 for adhering the fabric perow 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 fabric perow interference filter 10 and the third layer substrate 73 is the first layer substrate 71, the second layer substrate 72, the third layer substrate 73, the fourth layer substrate 74, and the first. It is smaller than the elastic modulus of the adhesive member (not shown) that adheres the 5-layer substrate 75 and the 6-layer substrate 76 to each other. For example, as a material for an adhesive member that adheres 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 substrate is used. If an adhesive containing a resin material is used, the Young rate after curing will be 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 transmission substrate 76a, a material corresponding to the measurement wavelength range of the light detection device 1B (for example, glass, silicon, germanium, etc.) 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, a metal such as aluminum, a metal oxide such as chromium oxide, a black resin, etc.) can be used. The light-shielding layer 76b is provided with an opening 76c. The light transmission 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 antireflection layer may be formed on at least one of the front surface and the back surface of the light transmission 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 Light having a predetermined wavelength is selectively transmitted according to the distance between the 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 unit 3a of the photodetector 3 and is detected by the photodetector 3. In the optical detection device 1B, the first mirror 31 and the second mirror 41 are moved 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). A spectroscopic spectrum can be obtained by detecting the transmitted light with the light detector 3.
[Structure 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. 5 and 6. In FIG. 6, the sixth layer substrate 76 and the like are omitted.

As shown in FIGS. 5 and 6, the mounting surface 73a of the third layer substrate 73 is the outer portion of the bottom surface 101 of the Fabry-Perot interference filter 10 and is the Fabry-Pérot 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. Of the side surfaces 102, the side surfaces (first side surface, second side surface) 102a and the side surface (first side surface, third side surface) 102b face each other with the light transmission region 11 interposed therebetween.

The side surface 102a is located on the mounting surface 73a so that a part of the mounting surface 73a is arranged on the outside of the side surface 102a (outside of the side surface 102 when viewed from the direction A). As a result, the corner portion C1 is formed by the side surface 102a and the outer portion of the mounting surface 73a on the outer side of the side surface 102a (the portion where the Fabry-Perot interference filter 10 is not mounted and is exposed). A part of the mounting surface 73a is arranged on the outside of the side surface 102c at one end of the side surface (fifth side surface) 102c on the corner portion 103a side which forms the corner portion 103a together with the side surface (fourth side surface) 102a. As such, it is located on the mounting surface 73a. As a result, the corner portion C2 is formed at one end of the side surface 102c and the outer portion of the mounting surface 73a outside one end of the side surface 102c (the portion where the Fabry-Perot interference filter 10 is not mounted and is exposed). Is formed. A part of the mounting surface 73a is arranged outside the side surface 102d at one end of the side surface (fifth side surface) 102d on the corner portion 103b side forming the corner portion 103b together with the side surface (fourth side surface) 102a. As such, it is located on the mounting surface 73a. As a result, the corner portion C3 is formed at one end of the side surface 102d and the outer portion of the mounting surface 73a at one end of the side surface 102d (the portion where the Fabry-Perot interference filter 10 is not mounted and is exposed). Is formed. The above-mentioned side surface 102a, one end of the side surface 102c, and 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 so that a part of the mounting surface 73a is arranged outside the side surface 102b. As a result, the corner portion C4 is formed by the side surface 102b and the outer portion of the mounting surface 73a on the outer side of the side surface 102b (the portion where the Fabry-Perot interference filter 10 is not mounted and is exposed). A part of the mounting surface 73a is arranged outside the side surface 102c at the other end of the side surface (fifth side surface) 102c on the corner portion 103c side forming the corner portion 103c together with the side surface (fourth side surface) 102b. It is located on the mounting surface 73a so as to be. As a result, the other end of the side surface 102c and the outer portion of the mounting surface 73a outside the other end of the side surface 102c (the portion where the Fabry-Perot interference filter 10 is not mounted and is exposed) are cornered. Part C5 is formed. Of the side surface 102, a part of the mounting surface 73a is arranged outside the side surface 102d at the other end of the side surface (fifth side surface) 102d on the corner portion 103d side forming the corner portion 103d together with the side surface (fourth side surface) 102b. It is located on the mounting surface 73a so as to be. As a result, the other end of the side surface 102d and the outer portion of the mounting surface 73a outside the other end of the side surface 102d (the portion where the Fabry-Perot interference filter 10 is not mounted and is exposed) are cornered. Part C6 is formed. The other end of the side surface 102b, the other end of the side surface 102c, and the other 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 adhesive member 5 is arranged at each corner C1, C2, C3. The adhesive members 5 arranged at the corners C1, C2, and C3 are continuous with each other. That is, the adhesive members 5 arranged at the corners C1, C2, and C3 are continuous over the entire corner C1 and cover the corners 103a and 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, and C6 are continuous with each other. That is, the adhesive members 5 arranged at the corners C4, C5, and C6 are continuous over the entire corner C4 and cover the corners 103c and 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 the respective corner portions C1, C2, and C3, and is continuous via the respective corner portions 103a and 103b. The second portion 5b is a portion arranged 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 portion 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. In the corner portion 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 arranged 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 arranged at each corner C4, C5, C6 includes a first portion 5a and a second portion 5b. The first portion 5a is a portion arranged along each corner portion C4, C5, C6, and is continuous via the respective corner portions 103c, 103d. The second portion 5b is a portion arranged 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 mounting surface 73a, and the inner surface 74a of the opening of the fourth layer substrate 74. In the corner portion 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 portion 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 corner portion C1, C2, C3, the edge portion 5c on the side surface 102 side, which is the highest 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, and C3 are in contact with the substrate 14 on the side surface 102. Similarly, in each corner portion C4, C5, C6, the edge portion 5c on the side surface 102 side, which is the highest 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, and 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 (fabripelling 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 light detection device 1B, the adhesive member 5 having an elastic modulus smaller than the elastic modulus of the third layer substrate 73 is arranged at the corners C1, C2, C3, C4, C5, C6, and is a fabric perow interference filter. It is in contact with each of the side surface 102 and a part of the mounting surface 73a of the third layer substrate 73. As a result, 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 stress generated in the Fabry-Perot interference filter 10 due to the difference in thermal expansion coefficient between the two and the Fabry-Perot interference filter 10 can be sufficiently absorbed by the adhesive member 5. Further, for example, the Fabry-Pérot interference filter 10 is more stable than 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. It can be more firmly held on the third layer substrate 73 in the state. Therefore, according to the light detection device 1B, the temperature characteristic of the transmission wavelength in the Fabry-Perot interference filter 10 can be sufficiently improved, and the holding state of the Fabry-Pérot interference filter 10 on the third layer substrate 73 can be stabilized. Can be done. The adhesive member 5 is another member constituting the light detection device 1B (not only the third layer substrate 73, but also the fabric perow interference filter 10, the first layer substrate 71, the second layer substrate 72, and the fourth layer substrate 74). , 5th layer substrate 75, 6th layer substrate 76, etc.) It is preferable to have an elastic modulus smaller than the elastic modulus.

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 the direction perpendicular to the surface 73a. 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 constituting the light detection device 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 characteristic of the transmission wavelength of the Fabry-Pérot interference filter 10 and the stabilization of the holding state of the Fabry-Pérot interference filter 10 on the third layer substrate 73. Therefore, it is preferable that the adhesive member 5 is in contact with the mounting surface 73a over the entire width of the portion of the mounting surface 73a that projects outward from the side surface 102.

Further, in the light detection device 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 surface 102 of the fabric perlow interference filter 10. 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 constituting the light detection device 1B is more sufficiently absorbed by the adhesive 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 more stabilized.

Further, in the photodetector 1B, the adhesive member 5 is arranged on the corner portion C1 so as to be continuous over the entire corner portion C1 formed by the side surface 102a of the Fabry-Perot interference filter 10, and is arranged 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 a plurality of adhesive members 5 are intermittently arranged in each corner C1 and C4, or the adhesive member 5 is arranged only in one place in a part of each corner C1 and C4. Compared with the case, the stress generated in the fabric perow interfering filter 10 due to the difference in the coefficient of thermal expansion between the fabric perow interfering filter 10 and the other members constituting the optical detection device 1B is uniformly absorbed by the adhesive member 5. be able to.

Further, in the photodetector 1B, the adhesive member 5 is arranged at the corner portion 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. As a result, the Fabry-Perot interference filter 10 can be held on the third layer substrate 73 in a more stable state.

Further, in the light detection device 1B, the adhesive members 5 arranged 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 the 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 the outside. As a result, the corner portions 103a, 103b, in which 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 optical detection device 1B is likely to be concentrated. 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 (particularly, 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 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 has the optical characteristics (refractive index, transmittance, etc.) of the adhesive member 5 due to the change in the ambient temperature. ) Is not affected by the change. Further, the Fabry-Perot interference filter 10 is distorted or tilted due to the shrinkage of the adhesive member 5 during curing and the stress generated by the expansion and contraction of the adhesive member 5 due to the change in ambient temperature during use. Is suppressed.

Further, in the light detection device 1B, a horizontally long space (a space 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) is provided on both sides of the fabric perow interference filter in the direction A. Further, in the light detection 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 edges of the SMD package 7. Further, in the light detection device 1B, the space provided on the light incident side of the fabric perot interference filter 10 is wider in the direction perpendicular to the direction A than the space provided on the light emitting side of the fabric perot interference filter 10. Is big. On the other hand, in the light detection device 1B, the space provided on the light emitting side of the Fabry-Perot interference filter 10 is in a direction parallel to the direction A than the space provided on the light incident side of the Fabry-Perot interference filter 10. The width is large. Further, in the optical detection device 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 the wiring provided in the SMD package 7.

As a result, the photodetector 1B can be miniaturized. Further, by providing horizontally long spaces on both sides of the Fabry-Pérot interference filter in the direction A, the distance between the opening 76c of the sixth layer substrate 76 and the Fabry-Pérot interference filter 10 can be determined as compared with the case where the vertically long spaces are provided. Further, the distance between the Fabry-Perot interference filter 10 and the optical detector 3 can be kept small. Therefore, even if the light is incident at a slight angle 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 photodetector 3a of the photodetector 3. Can be done. Further, by providing 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 is lowered as compared with the case where the vertically long spaces are provided, and the SMD package 7 is provided. The volume of the 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.

Although the first and second embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned first and second embodiments. For example, in the first embodiment, the adhesive member 5 includes a 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 includes the adhesive member 5. , If the first portion 5a is included, the second portion 5b may not be included. Similarly, in the second embodiment, the adhesive member 5 includes a 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 may 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, as the material and shape of each configuration, not only the above-mentioned material and shape but also 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 as separate bodies from each other. As shown in the above, the bottom surface 101 of the Fabry-Perot interference filter 10 may be mounted on the mounting surface 70a of the support (support) 70 corresponding to the one formed by integrating these substrates. In this case, the SMD package formed is 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 and bonded to each other. There is little variation in shape for each of 7. Further, since the 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 unnecessary, the periphery The change in the 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 the moisture contained in the outside air 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 the moisture. It is possible to suppress the deterioration with. 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 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 be in contact with the side surface of the substrate 14, but may be in contact with the side surface of the laminated body 50.

1A, 1B ... Photodetector, 3 ... Photodetector, 4,4A, 4B ... Spacer (support member), 4a ... Mounting surface, 5 ... Adhesive member, 5a ... First part, 5b ... Second part, 10 ... Fabry-Perot interference filter, 11 ... light transmission 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.

Claims (10)

A Fabry-Perot interference filter having a first mirror and a second mirror having a variable distance and having a light transmission region for transmitting light according to the distance between the first mirror and the second mirror.
A photodetector that detects light that has passed through the light transmission region,
The Fabry-Perot interference filter and the package containing the photodetector are provided.
The package is
A support that supports the Fabry-Perot interference filter and the photodetector, and
It has a light transmitting substrate that transmits light incident on the light transmitting region, and has.
In the package, the first space on the light incident side of the Fabry-Pérot interference filter in the direction in which light is transmitted through the light transmission region, and the Fabry-Pérot interference filter in the direction in which light is transmitted through the light transmission region. There is a second space on the light emitting side of
In each of the first space and the second space, the width in the direction perpendicular to the direction in which light is transmitted through the light transmission region is larger than the width in the direction parallel to the direction in which light is transmitted through the light transmission region. Is also a large space,
The second space has a larger width in the direction parallel to the direction in which light is transmitted through the light transmission region than the first space.
The support is
The mounting surface on which the Fabry-Pérot interference filter is mounted and
A photodetector having an inner surface extending from the above-mentioned mounting surface toward the light transmitting substrate side and facing the side surface of the Fabry-Perot interference filter. 1. Light detector. The photodetector according to claim 1 or 2, wherein the first space and the second space communicate with each other. The photodetector according to any one of claims 1 to 3, wherein the photodetector is arranged in the second space. The photodetector according to any one of claims 1 to 4, wherein the first space has a larger width in a direction perpendicular to the direction in which light is transmitted through the light transmission region than the second space. .. The package is
The invention according to any one of claims 1 to 5, further comprising a light-shielding layer provided on the light-transmitting substrate and having an opening facing the light-transmitting region in the direction in which light is transmitted through the light-transmitting region. Light detector. Further, an adhesive member for adhering the Fabry-Perot interference filter and the support is provided.
The photodetector according to any one of claims 1 to 6, wherein the elastic modulus of the adhesive member is smaller than the 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 7, wherein the Fabry-Perot interference filter is electrically connected to the electrode pad via wiring provided on the support. The support is configured by laminating a plurality of substrates.
The plurality of substrates are
The first substrate on which the first opening is formed and
A second substrate laminated on the first substrate on the light transmitting substrate side to form a second opening, and the like.
When the light transmitting region is viewed from the direction in which light is transmitted, the second opening includes the first opening.
The region of the surface of the first substrate on the light transmitting substrate side exposed to the second opening is the previously described mounting surface on which the outer portion of the bottom surface of the Fabry-Perot interference filter is mounted. The light detection device according to any one of claims 1 to 8. The photodetector according to any one of claims 1 to 8, wherein the support is integrally formed.

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