JP2019002941A - Spectrometer - Google Patents

Abstract

To provide a spectrometer that can be downsized while being prevented from detecting less accurately.SOLUTION: The spectrometer includes: a light detection unit having a substrate made of a semiconductor material; a base wall part facing the light detection unit across a space; a supporting body having a side wall part, to which the light detection unit is fixed; and a spectroscopic part for dispersing and reflecting light that has entered the space, to a light detection part of the light detection unit. The substrate has a first slit for transmitting light to enter the space and a second slit for transmitting a part of light reflected from the spectroscopic part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a spectroscope for spectrally detecting light.

  For example, Patent Document 1 discloses a light incident part, a spectroscopic part that splits and reflects light incident from the light incident part, a light detection element that detects light reflected and reflected by the spectroscopic part, and light. A spectroscope is described that includes an incident part, a spectroscopic part, and a box-like support that supports a light detection element.

JP 2000-298066 A

  The spectroscope as described above is required to be further downsized in accordance with the expansion of applications. However, the smaller the spectroscope is, the more easily the detection accuracy of the spectroscope decreases due to various causes.

  Therefore, an object of the present invention is to provide a spectroscope that can be reduced in size while suppressing a decrease in detection accuracy.

  The spectroscope of the present invention includes a photodetection unit having a substrate made of a semiconductor material, a base wall portion facing the photodetection unit through a space, and a support having a side wall portion to which the photodetection unit is fixed, A light splitting unit that splits and reflects the light incident on the space with respect to the light detection unit of the light detection unit, and is reflected on the substrate by the first slit through which the light incident on the space passes and the light splitting unit. A second slit through which a part of the light passes is formed.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the spectrometer which can achieve size reduction, suppressing the fall of detection accuracy.

It is sectional drawing of the spectrometer of 1st Embodiment of this invention. It is a top view of the spectrometer of a 1st embodiment of the present invention. It is sectional drawing of the modification of the spectrometer of 1st Embodiment of this invention. It is sectional drawing of the modification of the spectrometer of 1st Embodiment of this invention. It is sectional drawing of the spectrometer of 2nd Embodiment of this invention. It is a top view of the spectrometer of 2nd Embodiment of this invention. It is sectional drawing of the spectrometer of 3rd Embodiment of this invention. It is sectional drawing along the VIII-VIII line of FIG. It is sectional drawing of the spectrometer of 4th Embodiment of this invention. It is sectional drawing along the XX line of FIG. It is a figure which shows the relationship between size reduction of a spectrometer and the curvature radius of a spectroscopic part. It is a figure which shows the structure of the spectrometer of a comparative example.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or equivalent part, and the overlapping description is abbreviate | omitted.
[First Embodiment]

  As shown in FIGS. 1 and 2, the spectroscope 1 </ b> A includes a light detection element 20, a support 30, a first reflection unit 11, a second reflection unit 12, a spectroscopy unit 40, a cover 50, It has. The light detection element 20 is provided with a light passage part 21, a light detection part 22, and a zero-order light capturing part 23. The support 30 is provided with wiring 13 for inputting / outputting electric signals to / from the light detection unit 22. The support 30 is fixed to the light detection element 20 so that a space S is formed between the light passage part 21, the light detection part 22, and the zero-order light capturing part 23. As an example, the spectroscope 1A is formed in a rectangular parallelepiped shape in which the length in each of the X-axis direction, the Y-axis direction, and the Z-axis direction is 10 mm or less. In addition, the wiring 13 and the support body 30 are comprised as a molded circuit component (MID: Molded Interconnect Device).

  The light passing unit 21, the first reflecting unit 11, the second reflecting unit 12, the spectroscopic unit 40, the light detecting unit 22, and the zero-order light capturing unit 23 are in the optical axis direction of the light L1 that passes through the light passing unit 21 (that is, When viewed from the (Z-axis direction), they are aligned along the reference line RL extending in the X-axis direction. In the spectroscope 1 </ b> A, the light L <b> 1 that has passed through the light passage unit 21 is sequentially reflected by the first reflection unit 11 and the second reflection unit 12, enters the spectroscopic unit 40, and is split and reflected by the spectroscopic unit 40. . Of the light split and reflected by the spectroscopic unit 40, the light L2 other than the 0th-order light L0 enters the light detection unit 22 and is detected by the light detection unit 22, and the 0th-order light L0 is 0. The light enters the next light capturing unit 23 and is captured by the zero order light capturing unit 23. The optical path of the light L1 from the light passing part 21 to the spectroscopic part 40, the optical path of the light L2 from the spectroscopic part 40 to the light detection part 22, and the optical path of the 0th order light L0 from the spectroscopic part 40 to the zeroth order light capturing part 23 are , Formed in the space S.

  The light detection element 20 has a substrate 24. The substrate 24 is formed in a rectangular plate shape by a semiconductor material such as silicon. The light passing part 21 is a slit formed in the substrate 24 and extends in the Y-axis direction. The zero-order light capturing unit 23 is a slit formed in the substrate 24 and extends in the Y-axis direction between the light passing unit 21 and the light detecting unit 22. Note that the end of the light passing portion 21 on the incident side of the light L1 spreads toward the incident side of the light L1 in each of the X-axis direction and the Y-axis direction. Further, the end of the 0th-order light capturing unit 23 opposite to the incident side of the 0th-order light L0 is opposite to the incident side of the 0th-order light L0 in each of the X-axis direction and the Y-axis direction. It is spreading towards the end. By configuring the 0th-order light L0 to be incident on the 0th-order light capturing unit 23 obliquely, the 0th-order light L0 incident on the 0th-order light capturing unit 23 can be more reliably suppressed from returning to the space S. it can.

  The light detection unit 22 is provided on the surface 24 a on the space S side of the substrate 24. More specifically, the light detection unit 22 is not attached to the substrate 24 but is formed on the substrate 24 made of a semiconductor material. In other words, the light detection unit 22 includes a plurality of photodiodes formed by a first conductivity type region in the substrate 24 made of a semiconductor material and a second conductivity type region provided in the region. ing. The light detection unit 22 is configured as a photodiode array, a C-MOS image sensor, a CCD image sensor, or the like, for example, and has a plurality of light detection channels arranged along the reference line RL. Light L2 having a different wavelength is incident on each light detection channel of the light detection unit 22. A plurality of terminals 25 for inputting / outputting electrical signals to / from the light detection unit 22 are provided on the surface 24 a of the substrate 24. The light detection unit 22 may be configured as a front-illuminated photodiode, or may be configured as a back-illuminated photodiode.

The support 30 includes a base wall portion 31, a pair of side wall portions 32, and a pair of side wall portions 33. The base wall portion 31 is opposed to the light detection element 20 in the Z-axis direction via the space S. The base wall 31 has a recess 34 that opens to the space S side, a plurality of protrusions 35 that protrude to the opposite side of the space S side, and a plurality of through holes 36 that open to the space S side and the opposite side thereof. Is formed. The pair of side wall portions 32 face each other in the X-axis direction with the space S interposed therebetween. The pair of side wall portions 33 oppose each other in the Y axis direction with the space S interposed therebetween. The base wall portion 31, the pair of side wall portions 32, and the pair of side wall portions 33 are integrally formed of ceramic such as AlN or Al ₂ O ₃ .

  The first reflecting portion 11 is provided on the support 30. More specifically, the first reflecting portion 11 is provided on a flat inclined surface 37 that is inclined at a predetermined angle in the surface 31 a on the space S side of the base wall portion 31 via the molding layer 41. The first reflecting portion 11 is a flat mirror made of a metal vapor deposition film such as Al or Au and having a mirror surface, and the light L1 that has passed through the light passing portion 21 in the space S is directed to the second reflecting portion 12. reflect. In addition, the 1st reflection part 11 may be directly formed in the inclined surface 37 of the support body 30 without the molding layer 41 interposed.

  The second reflection unit 12 is provided in the light detection element 20. More specifically, the second reflecting portion 12 is provided in a region between the light passing portion 21 and the 0th-order light capturing portion 23 on the surface 24 a of the substrate 24. The second reflection unit 12 is a flat mirror made of a metal vapor deposition film such as Al or Au and having a mirror surface, and the light L1 reflected by the first reflection unit 11 in the space S is transmitted to the spectroscopic unit 40. reflect.

  The spectroscopic unit 40 is provided on the support 30. More specifically, it is as follows. That is, the molding layer 41 is disposed on the surface 31 a of the base wall portion 31 so as to cover the recess 34. The molding layer 41 is formed in a film shape along the inner surface 34 a of the recess 34. In the predetermined region of the molding layer 41 corresponding to the spherical region of the inner surface 34a, for example, a grating pattern corresponding to a blazed grating having a sawtooth cross section, a binary grating having a rectangular cross section, a holographic grating having a sinusoidal cross section, etc. 41a is formed. On the surface of the molding layer 41, a reflective film 42 made of a metal vapor deposition film such as Al or Au is formed so as to cover the grating pattern 41a. The reflective film 42 is formed along the shape of the grating pattern 41a, and this portion is a spectroscopic unit 40 that is a reflective grating. The molding layer 41 is pressed against a molding material (for example, a photocurable epoxy resin, acrylic resin, fluororesin, silicone, replica optical resin such as an organic / inorganic hybrid resin), and the state Then, the molding material is cured (for example, photocuring with UV light or the like, thermosetting or the like).

  As described above, the spectroscopic portion 40 is provided on the inner surface 34 a of the recess 34 in the surface 31 a of the base wall portion 31. The spectroscopic unit 40 includes a plurality of grating grooves arranged along the reference line RL. In the space S, the light L1 reflected by the second reflecting unit 12 is spectrally dispersed and reflected by the light detecting unit 22. To do. In addition, the spectroscopic part 40 is not limited to what was directly formed in the support body 30 as mentioned above. For example, the spectroscopic unit 40 may be provided on the support 30 by attaching a spectroscopic element having the spectroscopic unit 40 and a substrate on which the spectroscopic unit 40 is formed to the support 30.

  Each wiring 13 has an end portion 13a on the light detection portion 22 side, an end portion 13b on the opposite side to the light detection portion 22 side, and a connection portion 13c. The end 13 a of each wiring 13 is located on the end surface 32 a of each side wall 32 so as to face each terminal 25 of the light detection element 20. The end 13b of each wiring 13 is located on the surface of each convex portion 35 in the surface 31b on the side opposite to the space S side in the base wall portion 31. The connection portion 13c of each wiring 13 extends from the end portion 13a to the end portion 13b on the surface 32b on the space S side in each side wall portion 32, the surface 31a of the base wall portion 31, and the inner surface of each through hole 36. In this way, the wiring 13 can be prevented from being deteriorated by being routed around the space S side surface of the support 30.

  The terminals 25 of the opposing light detection elements 20 and the end portions 13a of the wiring 13 are connected by bumps 14 made of, for example, Au or solder. In the spectrometer 1 </ b> A, the support 30 is fixed to the light detection element 20 by a plurality of bumps 14, and the plurality of wirings 13 are electrically connected to the light detection unit 22 of the light detection element 20. As described above, the end portion 13 a of each wiring 13 is connected to each terminal 25 of the light detection element 20 at the fixing portion between the light detection element 20 and the support 30.

  The cover 50 is fixed to the surface 24 b of the substrate 24 of the photodetecting element 20 on the side opposite to the space S side. The cover 50 includes a light transmission member 51 and a light shielding film 52. The light transmitting member 51 is formed in a rectangular plate shape by a material that transmits light L1, such as quartz, borosilicate glass (BK7), Pyrex (registered trademark) glass, Kovar glass, or the like. The light shielding film 52 is formed on the surface 51 a on the space S side in the light transmission member 51. A light passage opening 52a is formed in the light shielding film 52 so as to face the light passage portion 21 of the light detection element 20 in the Z-axis direction. The light passage opening 52a is a slit formed in the light shielding film 52, and extends in the Y-axis direction. In the spectroscope 1 </ b> A, the incident NA of the light L <b> 1 incident on the space S is defined by the light passage opening 52 a of the light shielding film 52 and the light passage portion 21 of the light detection element 20.

  When detecting infrared rays, silicon, germanium, or the like is also effective as a material for the light transmission member 51. Further, the light transmission member 51 may be provided with an AR (Anti Reflection) coat or may have a filter function of transmitting only light of a predetermined wavelength. Further, as a material of the light shielding film 52, for example, black resist, Al, or the like can be used. However, from the viewpoint of suppressing the 0th-order light L0 incident on the 0th-order light capturing unit 23 from returning to the space S, a black resist is effective as the material of the light shielding film 52.

  Between the surface 24a of the substrate 24, the end surface 32a of each side wall portion 32, and the end surface 33a of each side wall portion 33, a sealing member 15 made of, for example, resin is disposed. Further, in the through hole 36 of the base wall portion 31, for example, a sealing member 16 made of glass beads or the like is disposed and a sealing member 17 made of resin is filled. In the spectroscope 1 </ b> A, the space S is hermetically sealed by a package 60 </ b> A including the light detection element 20, the support 30, the cover 50, and the sealing members 15, 16, and 17 as components. When the spectrometer 1A is mounted on an external circuit board, the end portion 13b of each wiring 13 functions as an electrode pad. Instead of disposing the cover 50 on the surface 24b of the substrate 24, the light transmitting portion 21 of the substrate 24 is hermetically sealed by filling the light transmitting portion 21 of the substrate 24 with a light transmitting resin. May be. Alternatively, only the sealing member 17 made of resin may be filled in the through hole 36 of the base wall portion 31 without arranging the sealing member 16 made of, for example, glass beads.

  As described above, in the spectroscope 1 </ b> A, an optical path from the light passage unit 21 to the light detection unit 22 is formed in the space S formed by the light detection element 20 and the support 30. Thereby, size reduction of the spectrometer 1A can be achieved. Further, the light L1 that has passed through the light passage unit 21 is sequentially reflected by the first reflection unit 11 and the second reflection unit 12 and enters the spectroscopic unit 40. This makes it easy to adjust the incident direction of the light L1 incident on the spectroscopic unit 40 and the spread or convergence state of the light L1, so that the optical path length from the spectroscopic unit 40 to the light detection unit 22 is shortened. In addition, the light L2 separated by the spectroscopic unit 40 can be condensed at a predetermined position of the light detection unit 22 with high accuracy. Therefore, according to the spectroscope 1A, it is possible to reduce the size while suppressing a decrease in detection accuracy.

  In the spectroscope 1A, the light passage unit 21, the first reflection unit 11, the second reflection unit 12, the spectroscopy unit 40, and the light detection unit 22 are viewed from the optical axis direction of the light L1 that passes through the light passage unit 21. In this case, they are arranged along the reference line RL. The spectroscopic unit 40 has a plurality of grating grooves arranged along the reference line RL, and the light detection unit 22 has a plurality of light detection channels arranged along the reference line RL. Thereby, the light L2 split by the spectroscopic unit 40 can be condensed on each photodetection channel of the photodetection unit 22 with higher accuracy.

  In the spectroscope 1A, the first reflecting portion 11 is a plane mirror. As a result, the incident NA of the light L1 passing through the light passage 21 is reduced, and “the optical path length of the light L1 having the same divergence angle as the light L1 that has passed through the light passage 21 is The optical path length from the spectral unit 40 to the spectroscopic unit 40 >> “the optical path length from the spectroscopic unit 40 to the photodetecting unit 22” (reduction optical system) makes the resolution of the light L2 split by the spectroscopic unit 40 higher. be able to. Specifically, it is as follows. That is, when the 1st reflection part 11 is a plane mirror, the light L1 is irradiated to the spectroscopy part 40, spreading. Therefore, from the viewpoint of suppressing the area of the spectroscopic unit 40 from being widened and from the viewpoint of suppressing the distance that the spectroscopic unit 40 collects the light L2 on the light detection unit 22 from being long, the light passing unit 21 is changed. It is necessary to reduce the incident NA of the passing light L1. Therefore, by reducing the incident NA of the light L1 and using a reduction optical system, the resolution of the light L2 split by the spectroscopic unit 40 can be increased.

  In the spectroscope 1A, the light detection element 20 is provided with a 0th-order light capturing unit 23 that captures the 0th-order light L0 of the light that is split and reflected by the spectroscopic unit 40. Thereby, it can suppress that 0th-order light L0 becomes stray light by multiple reflection etc., and a detection accuracy falls.

  In the spectroscope 1 </ b> A, the support 30 is provided with the wiring 13 that is electrically connected to the light detection unit 22. The end 13 a of the wiring 13 on the side of the light detection unit 22 is connected to a terminal 25 provided on the light detection element 20 at a fixing portion between the light detection element 20 and the support 30. Thereby, the electrical connection between the light detection unit 22 and the wiring 13 can be ensured.

  In the spectroscope 1A, the material of the support 30 is ceramic. Thereby, the expansion | swelling and shrinkage | contraction of the support body 30 resulting from the temperature change of the environment where the spectrometer 1A is used, the heat_generation | fever in the photon detection part 22, etc. can be suppressed. Accordingly, it is possible to suppress a decrease in detection accuracy (such as a shift in peak wavelength in the light detected by the light detection unit 22) due to a shift in the positional relationship between the spectroscopic unit 40 and the light detection unit 22. Since the spectroscope 1A is downsized, even a slight change in the optical path may greatly affect the optical system and lead to a decrease in detection accuracy. Therefore, especially when the spectroscopic unit 40 is directly formed on the support 30 as described above, it is extremely important to suppress the expansion and contraction of the support 30.

  In the spectroscope 1A, the space S is hermetically sealed by a package 60A including the light detection element 20 and the support 30 as components. Thereby, the deterioration of the detection accuracy resulting from the generation | occurrence | production of the dew condensation in the space S by the deterioration of the member in the space S by humidity, and the fall of external temperature can be suppressed.

  In the spectroscope 1 </ b> A, the second reflection unit 12 is provided in the light detection element 20. Since the surface 24a of the substrate 24 on which the second reflecting portion 12 is formed in the light detecting element 20 is a flat surface, and the second reflecting portion 12 can be formed in the manufacturing process of the light detecting element 20, it is desirable. The second reflecting portion 12 corresponding to the NA can be formed with high accuracy.

  Further, in the spectroscope 1A, a flat region (may be slightly inclined) exists around the recess 34 in the surface 31a of the base wall portion 31. Thereby, even if reflected light is generated in the light detection unit 22, the reflected light can be prevented from reaching the light detection unit 22 again. Further, when the molding layer 41 is formed on the inner surface 34 a of the recess 34 by pressing the molding die against the resin, and between the surface 24 a of the substrate 24, the end surface 32 a of each side wall portion 32, and the end surface 33 a of each side wall portion 33. In addition, when the sealing member 15 made of resin is disposed, the flat region becomes an escape place for excess resin. At this time, if an excess resin is poured into the through hole 36 of the base wall portion 31, the sealing member 16 made of, for example, glass beads becomes unnecessary, and the resin functions as the sealing member 17.

  Further, in the manufacturing process of the spectroscope 1A, as described above, a smooth molding layer 41 is formed on the inclined surface 37 of the base wall portion 31 using a molding die, and the first reflecting portion 11 is formed on the molding layer 41. Is forming. Usually, since the surface of the molding layer 41 is smoother with less unevenness than the surface of the support 30, the first reflecting portion 11 having a mirror surface can be formed with higher accuracy. However, in the case where the first reflecting portion 11 is directly formed on the inclined surface 37 of the base wall portion 31 without using the molding layer 41, the molding material used for the molding layer 41 can be reduced. Since the shape can be simplified, the molding layer 41 can be easily formed.

  As shown in FIG. 3, the cover 50 may further include a light shielding film 53 made of, for example, black resist or Al. The light shielding film 53 is formed on the surface 51 b of the light transmission member 51 on the side opposite to the space S side. A light passage opening 53a is formed in the light shielding film 53 so as to face the light passage portion 21 of the light detection element 20 in the Z-axis direction. The light passage opening 53a is a slit formed in the light shielding film 53 and extends in the Y-axis direction. In this case, the incident NA of the light L1 incident on the space S is more accurately defined using the light passage opening 53a of the light shielding film 53, the light passage opening 52a of the light shielding film 52, and the light passage portion 21 of the light detection element 20. be able to.

  Further, as shown in FIG. 4, the cover 50 further includes the light shielding film 53 described above, and the light is applied to the light shielding film 52 so as to face the 0th-order light capturing unit 23 of the light detection element 20 in the Z-axis direction. A passage opening 52b may be formed. In this case, it is possible to more reliably suppress the 0th-order light L0 incident on the 0th-order light capturing unit 23 from returning to the space S.

  Further, when the spectroscope 1A is manufactured, the support 30 provided with the first reflecting portion 11 and the spectroscopic portion 40 is prepared (first step), the light passing portion 21, the second reflecting portion 12, and the light detection. The light detection element 20 provided with the portion 22 is prepared (second step), and after that, the support 30 and the light detection element 20 are fixed so that the space S is formed. An optical path from the light to the light detection unit 22 is formed in the space S (third step). In this manner, an optical path from the light passage part 21 to the light detection part 22 is formed in the space S simply by fixing the support 30 and the light detection element 20. Therefore, according to the manufacturing method of the spectroscope 1A, it is possible to easily manufacture the spectroscope 1A that can be downsized while suppressing a decrease in detection accuracy. In addition, the execution order of the process which prepares the support body 30, and the process which prepares the photon detection element 20 is arbitrary.

In particular, when the spectroscope 1A is manufactured, the electrical connection between the wiring 13 and the light detection unit 22 can be achieved by simply connecting the end 13a of the wiring 13 provided on the support 30 to the terminal 25 of the light detection element 20. Not only a simple connection but also the fixing of the support 30 and the light detection element 20 and the formation of an optical path from the light passage part 21 to the light detection part 22 are realized.
[Second Embodiment]

  As shown in FIGS. 5 and 6, the spectrometer 1 </ b> B is mainly different from the spectrometer 1 </ b> A described above in that the first reflecting portion 11 is a concave mirror. In the spectroscope 1 </ b> B, the first reflecting portion 11 is provided in a spherical region of the inner surface 34 a of the concave portion 34 of the base wall portion 31 via the molding layer 41. The first reflecting part 11 is a concave mirror made of a metal vapor deposition film such as Al or Au and having a mirror surface, and the light L1 that has passed through the light passing part 21 in the space S is directed to the second reflecting part 12. reflect. In addition, the 1st reflection part 11 may be directly formed in the inner surface 34a of the recessed part 34 of the support body 30 without the shaping | molding layer 41 interposed. Further, the cover 50 may have the configuration shown in FIGS. 3 and 4.

According to the spectroscope 1B configured as described above, for the same reason as the spectroscope 1A described above, it is possible to reduce the size while suppressing a decrease in detection accuracy. In the spectroscope 1B, the first reflecting portion 11 is a concave mirror. Thereby, since the spread angle of the light L1 is suppressed by the first reflecting unit 11, the incident NA of the light L1 that passes through the light passing unit 21 is increased to increase the sensitivity, or from the spectroscopic unit 40 to the light detecting unit 22. It is possible to further reduce the size of the spectroscope 1B by shortening the optical path length. Specifically, it is as follows. That is, when the 1st reflection part 11 is a concave surface mirror, the light L1 is irradiated to the spectroscopy part 40 in the state collimated. Therefore, compared with the case where the light L1 is spread and irradiated to the spectroscopic unit 40, the distance at which the spectroscopic unit 40 collects the light L2 on the light detection unit 22 can be shortened. Therefore, the incident NA of the light L1 can be increased to increase the sensitivity, or the optical path length from the spectroscopic unit 40 to the light detection unit 22 can be shortened to further reduce the size of the spectroscope 1B. .
[Third Embodiment]

  As shown in FIGS. 7 and 8, the spectrometer 1 </ b> C differs from the spectrometer 1 </ b> A described above in that the space S is hermetically sealed by a package 60 </ b> B that houses the light detection element 20 and the support 30. Is different. The package 60B includes a stem 61 and a cap 62. The stem 61 is formed in a disk shape from metal, for example. The cap 62 is formed in a cylindrical shape from metal, for example. The stem 61 and the cap 62 are airtightly joined in a state where a flange portion 61 a provided at the outer edge of the stem 61 and a flange portion 62 a provided at the opening end of the cap 62 are in contact with each other. As an example, the hermetic sealing between the stem 61 and the cap 62 is performed in a nitrogen atmosphere in which dew point management (for example, −55 ° C.) is performed or in an evacuated atmosphere.

  A light incident part 63 is provided on the wall part 62 b facing the stem 61 in the cap 62 so as to face the light passing part 21 of the light detection element 20 in the Z-axis direction. The light incident part 63 is configured by airtightly joining the window member 64 to the inner surface of the wall part 62b so as to cover the light passage hole 62c formed in the wall part 62b. The light passage hole 62c has a shape including the light passage portion 21 when viewed from the Z-axis direction. The window member 64 is formed in a plate shape from a material that transmits light L1, such as quartz, borosilicate glass (BK7), Pyrex (registered trademark) glass, Kovar glass, or the like. In the spectroscope 1 </ b> C, the light L <b> 1 enters the light passing unit 21 from the outside of the package 60 </ b> B through the light incident unit 63. When detecting infrared rays, silicon, germanium, or the like is also effective as a material for the window member 64. The window member 64 may be provided with an AR coating or may have a filter function that transmits only light of a predetermined wavelength. Further, at least a part of the window member 64 may be disposed in the light passage hole 62c so that the outer surface of the window member 64 and the outer surface of the wall portion 62b are flush with each other.

  A plurality of through holes 61 b are formed in the stem 61. A lead pin 65 is inserted into each through hole 61b. Each lead pin 65 is airtightly fixed to each through hole 61b through a hermetic seal member made of glass for sealing such as low melting point glass having electrical insulation and light shielding properties. An end portion of each lead pin 65 in the package 60 </ b> B is connected to an end portion 13 b of each wiring 13 provided on the support body 30 on the surface 31 b of the base wall portion 31. Thereby, the electrical connection between the corresponding lead pin 65 and the wiring 13 and the positioning of the light detection element 20 and the support 30 with respect to the package 60B are realized.

  Note that the end of the lead pin 65 in the package 60B is disposed in the through hole formed in the through hole formed in the base wall portion 31 or in the recess formed in the surface 31b of the base wall portion 31. Or you may be connected to the edge part 13b of the wiring 13 extended in the said recessed part. Further, the end of the lead pin 65 in the package 60B and the end 13b of the wiring 13 may be electrically connected via a wiring board on which the support 30 is mounted by bump bonding or the like. In this case, the end of the lead pin 65 in the package 60B may be arranged so as to surround the support 30 when viewed from the thickness direction of the stem 61 (ie, the Z-axis direction). Further, the wiring board may be disposed on the stem 61 in contact with the stem 61, or may be supported by a plurality of lead pins 65 in a state of being separated from the stem 61.

  In the spectrometer 1C, the substrate 24 of the light detection element 20 and the base wall portion 31 of the support 30 are formed in a hexagonal plate shape, for example. Further, since the photodetecting element 20 and the support 30 are accommodated in the package 60B, in the spectroscope 1C, as in the spectroscope 1A described above, the surface 32b on the space S side and the base wall portion in each side wall portion 32. It is not necessary to route the connecting portion 13c of each wiring 13 on the surface 31a of the 31 and the inner surface of each through hole 36. In the spectroscope 1C, the connection portion 13c of each wiring 13 extends from the end portion 13a to the end portion 13b on the surface of each side wall portion 32 opposite to the space S side and the surface 31b of the base wall portion 31. As described above, the wiring 13 is routed around the surface of the support 30 opposite to the space S side, whereby light scattering by the wiring 13 exposed in the space S can be prevented. Further, in the spectrometer 1C, it is not necessary to dispose the sealing members 15, 16, and 17 and to provide the cover 50 as in the above-described spectrometer 1A.

  According to the spectroscope 1C configured as described above, for the same reason as the spectroscope 1A described above, it is possible to reduce the size while suppressing a decrease in detection accuracy. In the spectroscope 1C, the space S is hermetically sealed by a package 60B that houses the light detection element 20 and the support 30. Thereby, the deterioration of the detection accuracy resulting from the generation | occurrence | production of the dew condensation in the space S by the deterioration of the member in the space S by humidity, and the fall of external temperature can be suppressed.

  In the spectroscope 1 </ b> C, a gap is formed between the end surface 32 a of each side wall portion 32 of the support 30 and the end surface 33 a of each side wall portion 33 and the surface 24 a of the substrate 24 of the light detection element 20. As a result, the influence of the deformation of the light detection element 20 does not easily reach the support body 30, and the influence of the deformation of the support body 30 hardly reaches the light detection element 20, so that the light passage section 21 changes to the light detection section 22. The reaching optical path can be maintained with high accuracy.

In the spectroscope 1 </ b> C, the support 30 is supported by a plurality of lead pins 65 in a state of being separated from the stem 61. Thereby, since the influence of the deformation of the stem 61, the influence of the external force from the outside of the package 60B, and the like hardly reach the support body 30, the optical path from the light passage portion 21 to the light detection portion 22 can be accurately maintained. .
[Fourth Embodiment]

  As shown in FIGS. 9 and 10, the spectrometer 1 </ b> D is mainly different from the spectrometer 1 </ b> C described above in that the first reflecting portion 11 is a concave mirror. In the spectroscope 1 </ b> D, the first reflecting portion 11 is provided in a spherical region of the inner surface 34 a of the concave portion 34 of the base wall portion 31 via the molding layer 41. The first reflection unit 11 is a concave mirror made of a metal vapor deposition film such as Al or Au, and reflects the light L1 that has passed through the light passage unit 21 in the space S to the second reflection unit 12.

According to the spectroscope 1D configured as described above, for the same reason as the spectroscope 1A described above, it is possible to reduce the size while suppressing a decrease in detection accuracy. In the spectroscope 1D, the first reflecting portion 11 is a concave mirror. Thereby, since the spread angle of the light L1 is suppressed by the first reflecting unit 11, the incident NA of the light L1 that passes through the light passing unit 21 is increased to increase the sensitivity, or from the spectroscopic unit 40 to the light detecting unit 22. It is possible to further reduce the size of the spectroscope 1B by shortening the optical path length. In the spectroscope 1D, the space S is hermetically sealed by a package 60B that houses the light detection element 20 and the support 30. Thereby, the deterioration of the detection accuracy resulting from the generation | occurrence | production of the dew condensation in the space S by the deterioration of the member in the space S by humidity, and the fall of external temperature can be suppressed.
[Relationship between spectrometer downsizing and radius of curvature of spectroscopic section]

  As shown in FIG. 11, in the spectroscope of (a) and the spectroscope of (b), the light L <b> 1 that has passed through the light passage unit 21 is directly incident on the spectroscopic unit 40, and is split and reflected by the spectroscopic unit 40. The light L2 that has been directly incident on the light detection unit 22. In the spectroscope of (c), the light L1 that has passed through the light passing portion 21 is sequentially reflected by the first reflecting portion 11 and the second reflecting portion 12, enters the spectroscopic portion 40, is split by the spectroscopic portion 40, and is reflected. The light L2 that has been directly incident on the light detection unit 22. In the spectroscope (a), the radius of curvature of the inner surface 34a on which the spectroscopic portion 40 is formed is 6 mm. In the spectroscope (b), the radius of curvature of the inner surface 34a on which the spectroscopic portion 40 is formed is 3 mm. In the spectroscope of (c), the radius of curvature of the inner surface 34a on which the first reflecting portion 11 and the spectroscopic portion 40 are formed is 4 mm.

  First, comparing the spectroscope of (a) with the spectroscope of (b), the height of the spectroscope of (b) is higher than the height of the spectroscope of (a) (the height in the Z-axis direction). It is low. This is because the distance at which the spectroscopic unit 40 condenses the light L2 on the light detection unit 22 is shortened by the smaller radius of curvature of the inner surface 34a where the spectroscopic unit 40 is formed.

  However, as the radius of curvature of the inner surface 34a on which the spectroscopic portion 40 is formed becomes smaller, various problems appear as follows. That is, the focus line of the light L2 (a line connecting positions where the light L2 having different wavelengths is condensed) is likely to be distorted. Further, since the influence of various aberrations becomes large, it becomes difficult to correct the grating design. Further, since the diffraction angle toward the long wavelength side is particularly tight, it is necessary to narrow the grating pitch. However, when the grating pitch is narrowed, it becomes difficult to form the grating. Furthermore, blazing is necessary to increase the sensitivity, but blazing becomes difficult when the grating pitch is narrowed. In addition, since the diffraction angle toward the long wavelength side is particularly severe, the resolution of the light L2 is also disadvantageous.

  Such various problems appear when the light passing portion 21 as a slit is provided on the substrate 24 of the light detection element 20, and the light L1 passes along a direction perpendicular to the surfaces 24 a and 24 b of the substrate 24. This is because it is realistic to configure the light passage portion 21 as described above. Further, there is a restriction that the 0th-order light L0 must be reflected to the side opposite to the light detection unit 22 side.

  On the other hand, in the spectroscope of (c), although the curvature radius of the inner surface 34a on which the first reflecting portion 11 and the spectroscopic portion 40 are formed is 4 mm, it is compared with the height of the spectroscope of (b). The height of the spectroscope (c) is low. This is because the spectroscope of (c) uses the first reflecting portion 11 and the second reflecting portion 12 to adjust the incident direction of the light L1 incident on the spectroscopic portion 40 and the spread or convergence state of the light L1. Because it is possible to do.

As described above, when the light passing portion 21 as the slit is provided on the substrate 24 of the light detection element 20, the light passing portion is so passed that the light L1 passes along the direction perpendicular to the surface 24a and the surface 24b of the substrate 24. It is realistic to configure 21. Even in such a case, if the first reflection unit 11 and the second reflection unit 12 are used, the spectrometer can be downsized. In the spectroscope of (c), the 0th-order light L0 can be captured by the 0th-order light capturing unit 23 located between the second reflecting unit 12 and the light detection unit 22, which also reduces the detection accuracy of the spectrometer. This is a great feature for reducing the size of the spectroscope while suppressing the above.
[Superiority of the optical path from the spectroscopic section to the light detection section]

  First, as shown in FIG. 12, a spectroscope employing an optical path from the light passage unit 21 to the light detection unit 22 through the first reflection unit 11, the spectroscopy unit 40, and the second reflection unit 12 in order. consider. In the spectroscope of FIG. 12, the light L1 is split and reflected by the spectroscopic unit 40 which is a planar grating. Then, the light L <b> 2 that is split and reflected by the spectroscopic unit 40 is reflected by the second reflecting unit 12 that is a concave mirror and enters the light detecting unit 22. In this case, each light L2 is incident on the light detection unit 22 so that the condensing positions of the respective lights L2 approach each other.

  In the spectroscope of FIG. 12, when the wavelength range of the light L2 to be detected is to be expanded, the radius of curvature of the inner surface 34a on which the spectroscopic unit 40 is formed and the distance between the second reflecting unit 12 and the photodetecting unit 22 are increased. There is a need. In addition, since each light L2 is incident on the light detection unit 22 so that the condensing positions of each light L2 approach each other, the radius of curvature of the inner surface 34a and the distance between the second reflection unit 12 and the light detection unit 22 are further increased. It needs to be bigger. If the grating pitch (grating groove interval) is narrowed and the interval between the condensing positions of the light beams L2 is excessively widened, it becomes difficult to align the focus line of the light beam L2 with the light detection unit 22. Thus, it can be said that the optical path from the light passing section 21 to the light detecting section 22 through the first reflecting section 11, the spectroscopic section 40, and the second reflecting section 12 is an unsuitable optical path for downsizing. .

  On the other hand, as shown in FIG. 11C, the optical path from the light passage unit 21 to the light detection unit 22 through the first reflection unit 11, the second reflection unit 12, and the spectroscopic unit 40 sequentially. In the adopted spectrometer (that is, the spectrometer corresponding to the above-described spectrometers 1A to 1D), each light L2 is incident on the light detection unit 22 so that the condensed positions of the respective lights L2 are separated from each other. Become. Therefore, it can be said that the optical path from the light passing part 21 to the light detecting part 22 through the first reflecting part 11, the second reflecting part 12, and the spectroscopic part 40 is an optical path suitable for miniaturization. In the spectrometer of FIG. 12, the radius of curvature of the inner surface 34a is 12 mm and the height (height in the Z-axis direction) is 7 mm, whereas in the spectrometer of FIG. The above can also be seen from the fact that the radius of curvature of the inner surface 34a is 4 mm and the height is about 2 mm.

  The first to fourth embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, in the first and second embodiments, the incident NA of the light L1 incident on the space S is caused by the light passing portion 21 of the light detection element 20 and the light passage opening 52a of the light shielding film 52 (in some cases, the light shielding film 53 Although it was defined by the shape of the light passage opening 53a), the light L1 incident on the space S can be adjusted by adjusting the shape of at least one region of the first reflecting portion 11, the second reflecting portion 12, and the spectroscopic portion 40. The incident NA can be substantially defined. Since the light L2 incident on the light detection unit 22 is diffracted light, the incident NA can be substantially defined by adjusting the shape of the predetermined region where the grating pattern 41a is formed in the molding layer 41.

  Further, in each of the above embodiments, the terminal 25 of the opposing light detection element 20 and the end 13a of the wiring 13 are connected by the bump 14, but the terminal 25 of the opposing light detection element 20 and the end of the wiring 13 are connected. 13a may be connected by soldering. Further, the connection between the terminal 25 of the photodetecting element 20 and the end portion 13 a of the wiring 13 is not limited to the end surface 32 a of each side wall portion 32 of the support 30, but also the end surface 33 a of each side wall portion 33 of the support 30. Or may be performed on the end surface 32 a of each side wall portion 32 and the end surface 33 a of each side wall portion 33 of the support 30. In the spectroscopes 1A and 1B, the wiring 13 may be routed on the surface of the support 30 opposite to the space S side. In the spectroscopes 1C and 1D, the wiring 13 may be routed on the surface of the support 30 on the space S side.

  Further, the material of the support 30 is not limited to ceramic, and may be other molding materials such as resins such as LCP, PPA, and epoxy, and glass for molding. The shape of the package 60B may be a rectangular box shape. Further, when the space S is hermetically sealed by the package 60 </ b> B that accommodates the light detection element 20 and the support body 30, the support body 30 has a pair of side wall portions 32 and a pair of side wall portions 33 that surround the space S. Instead, it may have a plurality of column parts or a plurality of side wall parts spaced apart from each other. Thus, the materials and shapes of the components of the spectrometers 1A to 1D are not limited to the materials and shapes described above, and various materials and shapes can be applied.

  The spectroscope of the present invention is a support body fixed to a light detection element so that a space is formed between the light detection element provided with the light passage part and the light detection part, and the light passage part and the light detection part. And a first reflecting portion that is provided on the support and reflects light that has passed through the light passing portion in the space; and a first reflecting portion that is provided on the light detection element and reflects light reflected by the first reflecting portion in the space. And a spectroscopic unit that is provided on the support and separates and reflects the light reflected by the second reflective unit in the space with respect to the photodetection unit.

  In this spectrometer, an optical path from the light passage part to the light detection part is formed in the space formed by the light detection element and the support. Thereby, size reduction of a spectrometer can be achieved. Furthermore, the light that has passed through the light passing portion is sequentially reflected by the first reflecting portion and the second reflecting portion and enters the spectroscopic portion. This makes it easy to adjust the incident direction of light incident on the spectroscopic unit and the spread or convergence state of the light, so even if the optical path length from the spectroscopic unit to the light detection unit is shortened, the spectroscopic unit The dispersed light can be condensed at a predetermined position of the light detection unit with high accuracy. Therefore, according to this spectrometer, it is possible to reduce the size while suppressing a decrease in detection accuracy.

  In the spectroscope according to the present invention, the light passing portion, the first reflecting portion, the second reflecting portion, the spectroscopic portion, and the light detecting portion are along the reference line when viewed from the optical axis direction of the light passing through the light passing portion. The spectroscopic unit may have a plurality of grating grooves arranged along the reference line, and the light detection unit may have a plurality of light detection channels arranged along the reference line. According to this configuration, it is possible to focus the light dispersed by the spectroscopic unit on each photodetection channel of the photodetection unit with higher accuracy.

  In the spectrometer of the present invention, the first reflecting unit may be a plane mirror. According to this configuration, the incident NA of the light passing through the light passage portion is reduced, and “the optical path length of the light having the same spread angle as the light passing through the light passage portion, By setting “optical path length to the spectroscopic section”> “optical path length from the spectroscopic section to the light detection section” (reduction optical system), the resolution of light split by the spectroscopic section can be increased.

  In the spectrometer of the present invention, the first reflecting portion may be a concave mirror. According to this configuration, since the light spreading angle is suppressed by the first reflecting unit, the sensitivity is increased by increasing the incident NA of the light passing through the light passing unit, or the optical path length from the spectroscopic unit to the light detecting unit. It is possible to further reduce the size of the spectrometer by shortening the length.

  In the spectroscope of the present invention, the light detection element may be provided with a 0th-order light capturing unit that captures 0th-order light out of the light that is split and reflected by the spectroscopic unit. According to this structure, it can suppress that 0th-order light becomes stray light and a detection accuracy falls.

  In the spectrometer of the present invention, the support is provided with a wiring electrically connected to the light detection unit, and the end of the wiring on the side of the light detection unit is a fixed part between the light detection element and the support. In the above, it may be connected to a terminal provided in the photodetecting element. According to this configuration, it is possible to ensure electrical connection between the light detection unit and the wiring.

  In the spectrometer of the present invention, the support material may be ceramic. According to this configuration, it is possible to suppress the expansion and contraction of the support due to the temperature change of the environment in which the spectroscope is used. Therefore, it is possible to suppress a decrease in detection accuracy (such as a shift in peak wavelength in light detected by the light detection unit) due to a shift in the positional relationship between the spectroscopic unit and the light detection unit.

  In the spectrometer of the present invention, the space may be hermetically sealed by a package including a light detection element and a support as components. According to this configuration, it is possible to suppress a decrease in detection accuracy caused by deterioration of members in the space due to moisture and generation of condensation in the space due to a decrease in outside air temperature.

  In the spectrometer of the present invention, the space may be hermetically sealed by a package that houses the light detection element and the support. According to this configuration, it is possible to suppress a decrease in detection accuracy caused by deterioration of members in the space due to moisture and generation of condensation in the space due to a decrease in outside air temperature.

  The method of manufacturing a spectroscope according to the present invention includes a first step of preparing a support body provided with a first reflecting portion and a spectroscopic portion, and a light detecting element provided with a light passing portion, a second reflecting portion, and a light detecting portion. After the first step and the first step and the second step, the support and the light detection element are fixed so that a space is formed, so that the light that has passed through the light passing portion is the first reflecting portion. The light reflected by the first reflection unit and reflected by the first reflection unit is reflected by the second reflection unit, and the light reflected by the second reflection unit is dispersed and reflected by the spectroscopic unit, and is dispersed and reflected by the spectroscopic unit. A third step of forming, in the space, an optical path for the incident light to enter the light detection unit.

  In this method of manufacturing a spectroscope, the space provided by simply fixing the support provided with the first reflecting part and the spectroscopic part and the light detecting element provided with the light passing part, the second reflecting part, and the light detecting part is provided. Inside, an optical path from the light passing part to the light detecting part is formed. Therefore, according to this method for manufacturing a spectrometer, it is possible to easily manufacture a spectrometer that can be reduced in size while suppressing a decrease in detection accuracy. In addition, the execution order of a 1st process and a 2nd process is arbitrary.

  DESCRIPTION OF SYMBOLS 1A, 1B, 1C, 1D ... Spectroscope, 11 ... 1st reflection part, 12 ... 2nd reflection part, 13 ... Wiring, 13a ... End part, 20 ... Photodetection element, 21 ... Light passage part, 22 ... Light detection Part, 23 ... 0th-order light capturing part, 25 ... terminal, 30 ... support, 40 ... spectral part, 60A, 60B ... package, S ... space, RL ... reference line.

Claims (4)

A light detection unit having a substrate made of a semiconductor material;
A base wall part facing the light detection unit through a space, and a support body having a side wall part to which the light detection unit is fixed;
A spectroscopic unit that splits and reflects the light incident on the space with respect to the photodetection unit of the photodetection unit,
The spectroscope, wherein the substrate is formed with a first slit through which light incident on the space passes and a second slit through which a part of the light reflected by the spectroscopic unit passes. The light incident side end of the first slit is divergent toward the light incident side,
2. The spectroscope according to claim 1, wherein an end of the second slit on the side opposite to the light incident side is widened toward the side opposite to the light incident side.   The spectroscope according to claim 1, wherein the light detection unit further includes a cover disposed on a side opposite to the space side with respect to the substrate.   The spectroscope according to claim 3, wherein the cover is provided with a third slit facing the first slit.

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