Patent Publication Number: US-11022493-B2

Title: Spectroscope and method for producing spectroscope

Description:
TECHNICAL FIELD 
     The present invention relates to a spectrometer which disperses and detects light, and a method for manufacturing the spectrometer. 
     BACKGROUND ART 
     For example, Patent Literature 1 discloses a spectrometer including a light entrance part, a dispersive part for dispersing and reflecting light incident thereon from the light entrance part, a light detection element for detecting the light dispersed and reflected by the dispersive part, and a box-shaped support for supporting the light entrance part, dispersive part, and light detection element. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: Japanese Unexamined Patent Publication No. 2000-298066 
     SUMMARY OF INVENTION 
     Technical Problem 
     The above-described spectrometer requires further miniaturization in response to expansion of use. However, as the spectrometer is further miniaturized, detection accuracy of the spectrometer more easily decreases due to various causes. 
     It is therefore an object of the present invention to provide a spectrometer which can attempt miniaturization while suppressing a decrease in detection accuracy, and a method for manufacturing a spectrometer capable of easily manufacturing such a spectrometer. 
     Solution to Problem 
     The spectrometer in accordance with one aspect of the present invention includes a light detection element having a substrate made of a semiconductor material, a light passing part provided in the substrate, and a light detection part put in the substrate, a support having a base wall part opposing the light detection element through a space between the light passing part and the light detection part, and side wall parts integrally formed with the base wall part, the light detection element being fixed to the side wall parts, the support being provided with a wiring electrically connected to the light detection part, and a dispersive part provided on a first surface of the base wall part on a side of the space and configured to disperse and reflect light passing through the light passing part to the light, detection part in the space, a first end part of the wiring on a side of the light detection part is connected to a terminal provided in the light detection element, and a second end part of the wiring on an opposite side from the side of the light detection part is positioned on a second surface of the base wall part on an opposite side from the side of the space. 
     In the spectrometer, an optical path from the light passing part to the light detection part is formed in the space which is formed by the light detection element and the support. In this way, miniaturization of the spectrometer may be attempted. Further, the wiring electrically connected to the light detection part is provided in the support, and the second end part of the wiring on the opposite side from the light detection part side is positioned on the second surface of the base wall part on the opposite side from the space side. In this way, even when an external force acts on the second end part of the wiring, the support is rarely distorted. Thus, it is possible to suppress a decrease in detection accuracy (a shift of a peak wavelength in light detected by the light detection part, etc.) resulting from occurrence of a variance in a positional relationship between the dispersive part and the light detection part. In addition, the second end part of the wiring is formed on the second surface of the base wall part, and thus an external force may be inhibited from acting on the light detection element at the time of mounting, and damage to the light detection element may be reduced when compared to a conventional art in which a circuit board is directly connected to the light detection element. Therefore, the spectrometer may attempt miniaturization while suppressing a decrease in detection accuracy. 
     In the spectrometer in accordance with one aspect of the present invention, a depression open to the side of the space may be formed in the base wall part, and the dispersive part may be provided on an inner surface of the depression. According to this configuration, it is possible to obtain the highly reliable dispersive part, and to attempt miniaturization of the spectrometer. Further, even when reflected light is generated in the light detection part, the reflected light may be inhibited from reaching the light detection part again by a region around the depression on the first surface of the base wall part. 
     In the spectrometer in accordance with one aspect of the present invention, the second end part of the wiring may be positioned in a region around the depression on the second surface of the base wall part when viewed in a thickness direction of the base wall part. According to this configuration, it is possible to inhibit the dispersive part from being deformed due to an external force acting on the second end part of the wiring. 
     The spectrometer in accordance with one aspect of the present invention may further include a first reflection part provided in the support and configured to reflect the light passing through the light passing part m the space, and a second reflection part provided in the light detection element and configured to reflect the light reflected by the first reflection part to the dispersive part in the space. According to this configuration, an incident direction of the light entering the dispersive part and a divergence or convergence state of the light may be easily adjusted. Thus, even when the length of the optical path from the dispersive part to the light detection part is made short, the light dispersed by the dispersive part may be accurately concentrated on a predetermined position of the light detection part. 
     In the spectrometer in accordance with one aspect of the present invention, the first end part of the wiring may be connected to the terminal of the light detection element in a fixed part of the light detection element and the support. According to this configuration, the electrical connection between the light detection part and the wiring may be secured. 
     In the spectrometer in accordance with one aspect of the present invention, a material of the support may be ceramic. According to this configuration, it is possible to suppress expansion and contraction of the support resulting from a temperature change of an environment in which the spectrometer is used, etc. Therefore, it is possible to more reliably suppress a decrease in detection accuracy (a shift of a peak wavelength in light detected by the light detection part, etc.) resulting from occurrence of a variance in a positional relationship between the dispersive part and the light detection part. 
     In the spectrometer in accordance with one aspect of the present invention, the space may be airtightly sealed by a package including the light detection element and the support as components. According to this configuration, if is possible to suppress a decrease in detection accuracy resulting from deterioration of a member in the space due to moisture, occurrence of condensation in the space due to a decrease in ambient temperature, etc. 
     In the spectrometer in accordance with one aspect of the present invention, the space may be airtightly sealed by a package accommodating the light detection element and the support. According to this configuration, it is possible to suppress a decrease in detection accuracy resulting from deterioration of a member in the space due to moisture, occurrence of condensation in the space due to a decrease in ambient temperature, etc. 
     The method for manufacturing a spectrometer in accordance with one aspect of the present invention includes a first step of preparing a support provided with a wiring and a dispersive part, a second step of preparing a light detection element provided with a substrate made of a semiconductor material, a light passing part provided in the substrate, and a light detection part put in the substrate, and a third step of fixing the support and the light detection element such that a space is formed after the first step and the second step, thereby forming, in the space, an optical path on which light passing through the light passing part is dispersed and reflected by the dispersive part, and the light dispersed and reflected by the dispersive part enters the light detection part, and electrically connecting the wiring to the light detection part. 
     In the method for manufacturing the spectrometer in accordance with one aspect of the present invention, the optical path from the light passing part to the light detection part is formed in the space, and the wiring is electrically connected to the light detection part only by fixing the support provided with the wiring and the dispersive part to the light detection element provided with the light passing part and the light detection part. Therefore, according to the method for manufacturing the spectrometer, it is possible to easily produce the spectrometer which can attempt miniaturization while suppressing a decrease in detection accuracy. The first step and the second step may be implemented in an arbitrary order. 
     Advantageous Effects of Invention 
     The present invention can provide a spectrometer which can attempt miniaturization while suppressing a decrease in detection accuracy, and a method for manufacturing a spectrometer capable of easily manufacturing such a spectrometer. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a cross-sectional view of a spectrometer in accordance with a first embodiment of the invention; 
         FIG. 2  is a plan view of the spectrometer in accordance with the first embodiment of the invention; 
         FIG. 3  is a cross-sectional view of a modified example of the spectrometer in accordance with the first embodiment of the invention; 
         FIG. 4  is a cross-sectional view of the modified example of the spectrometer in accordance with the first embodiment of the invention; 
         FIG. 5  is a cross-sectional view of a spectrometer in accordance with a second embodiment of the invention; 
         FIG. 6  is a plan view of the spectrometer in accordance with the second embodiment of the invention; 
         FIG. 7  is a cross-sectional view of a spectrometer in accordance with a third embodiment of the invention; 
         FIG. 8  is a cross-sectional view taken along the line VIII-VIII of  FIG. 7 ; 
         FIG. 9  is a cross-sectional view of a spectrometer in accordance with a fourth embodiment of the invention; 
         FIG. 10  is a cross-sectional view taken along the line X-X of  FIG. 9 ; 
         FIG. 11  is a diagram illustrating a relationship between miniaturization of a spectrometer and the radius of curvature of the spectrometer; and 
         FIG. 12  is a diagram illustrating a configuration of a spectrometer in accordance with a comparative example. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In the following, preferred embodiments of the present invention will be explained in detail with reference to the drawings. In the drawings, the same or equivalent parts will be referred to with the same signs while omitting their overlapping descriptions. 
     First Embodiment 
     As illustrated in  FIGS. 1 and 2 , a spectrometer  1 A includes a light detection element  20 , a support  30 , a first reflection part  11 , a second reflection part  12 , a dispersive part  40 , and a cover  50 . The light detection element  20  is provided with a light passing part  21 , a light detection part  22 , and a zero-order light capture part  23 . The support  30  is provided with a wiring  13  for inputting/outputting electric signals to/from the light detection part  22 . The support  30  is fixed to the light detection element  20  such that a space S is formed among the light passing part  21 , the light detection part  22 , and the zero-order light capture part  23 . For example, the spectrometer  1 A is formed in a shape of a rectangular parallelepiped, a length of which in each of an X-axis direction, a Y-axis direction, and a Z-axis direction is less than or equal to 10 mm. The wiring  13  and the support  30  are configured as a molded interconnect device (MID). 
     The light passing part  21 , the first reflection part  11 , the second reflection part  12 , the dispersive part  40 , the light detection part  22 , and the zero-order light capture part  23  are arranged side by side along a reference line RL that extends in the X-axis direction when viewed in an optical axis direction (that is, the Z-axis direction) of light L 1  passing through the light passing part  21 . In the spectrometer  1 A, the light L 1  passing through the light passing part  21  is reflected by the first reflection part  11  and the second reflection part  12  in sequence, enters the dispersive part  40 , and is dispersed and reflected in the dispersive part  40 . Then, light L 2  other than zero-order light L 0  in light dispersed and reflected in the dispersive part  40  enters tire light detection part  22  and is detected by the light detection part  22 . The zero-order light L 0  in the light dispersed and reflected in the dispersive part  40  enters the zero-order light capture part  23  and is captured by the zero-order light capture part  23 . An optical path of the light L 1  from the light passing part  21  to the dispersive part  40 , an optical path of the light L 2  from the dispersive part  40  to the light detection part  22 , and an optical path of the zero-order light L 0  from the dispersive part  40  to the zero-order light capture part  23  are formed in the space S. 
     The light detection element  20  includes a substrate  24 . For example, the substrate  24  is formed in a rectangular plate shape using a semiconductor material such as silicone. The light passing part  21  is a slit formed in the substrate  24 , and extends in the Y-axis direction. The zero-order light capture part  23  is a slit formed in the substrate  24 , and extends in the Y-axis direction between the light passing part  21  and the light detection part  22 . In the light passing part  21 , an end part on an entrance side of the light L 1  widens toward the entrance side of the light L 1  in each of the X- and Y-axis directions. In addition, in the zero-order light capture part  23 , an end part on the opposite side from an entrance side of the zero-order light L 0  widens toward the opposite side from the entrance side of the zero-order light L 0  in each of the X- and Y-axis directions. When the zero-order light L 0  is configured to obliquely enter the zero-order light capture part  23 , the zero-order light L 0  entering the zero order light capture part  23  may be more reliably inhibited from returning to the space S. 
     The light detection part  22  is provided on a surface  24   a  of the substrate  24  on the space S side. More specifically, the light detection part  22  is put in the substrate  24  made of the semiconductor material rather than being attached to the substrate  24 . That is, the light detection part  22  includes a plurality of photodiodes formed in a first conductivity type region inside the substrate  24  made of the semiconductor material and a second conductivity type region provided within the region. For example, the light detection part  22  is configured as a photodiode array, a C-MOS image sensor, a CCD image sensor, etc., and has a plurality of light detection channels arranged along the reference line RL. Lights L 2  having different wavelengths are let into the respective light detection channels of the light detection part  22 . A plurality of terminals  25  for inputting/outputting electric signals to/from the light detection part  22  is provided on the surface  24   a  of the substrate  24 . The light detection part  22  may be configured as a surface-incident photodiode or a back, surface-incident photodiode. For example, when the light detection part  22  is configured as the surface-incident photodiode, the light detection part  22  is positioned at the same height as that of a light exit of the light passing part  21  (that is, the surface  24   a  of the substrate  24  on the space S side). In addition, for example, when the light detection part  22  is configured as the back surface-incident photodiode, the light detection part  22  is positioned at the same height as that of a light entrance of the light passing part  21  (that is, a surface  24   b  of the substrate  24  on the opposite side from the space S side). 
     The support  30  has a base wall part  31 , a pair of side wall parts  32 , and a pair of side wall parts  33 . The base wall part  31  opposes the light detection element  20  in the Z-axis direction through the space S. A depression  34  open to the space S side, a plurality of projections  35  protruding to the opposite side from the space S side, and a plurality of through holes  36  open to the space S side and the opposite side from the space S side are formed in the base wall part  31 . The pair of side wall parts  32  opposes each other in the X-axis direction through the space S. The pair of side wall parts  33  opposes each other in the Y-axis direction through the space S. The base wall part  31 , the pair of side wall parts  32 , and the pair of side wall parts  33  are integrally formed using ceramic such as AlN or Al 2 O 3 . 
     The first reflection part  11  is provided in the support  30 . More specifically, the first reflection part  11  is provided on a flat inclined surface  37  inclined at a predetermined angle in a surface (first surface)  31   a  of the base wall part  31  on the space S side with a molded layer  41  interposed therebetween. For example, the first reflection part  11  is a planar mirror including a metal evaporated film of Al, Au, etc. and having a mirror surface. The first reflection part  11  reflects the light L 1  passing through the light passing part  21  to the second reflection part  12  in the space S. The first reflection part  11  may be directly formed on the inclined surface  37  of the support  30  without the molded layer  41  interposed therebetween. 
     The second reflection part  12  is provided in the light detection element  20 . More specifically, the second reflection part  12  is provided in a region between the light passing part  21  and the zero-order light capture part  23  on the surface  24   a  of the substrate  24 . For example, the second reflection part  12  is a planar mirror including a metal evaporated film of Al, Au, etc. and having a mirror surface. The second reflection part  12  reflects the light L 1 , which is reflected by the first reflection part  11 , to the dispersive part  40  in the space S. 
     The dispersive part  40  is provided in the support  30 . Details thereof are described below. That is, the molded layer  41  is disposed to cover the depression  34  on the surface  31   a  of the base wall part  31 . The molded layer  41  is formed into a film along an inner surface  34   a  of the depression  34 . For example, a grating pattern  41   a  corresponding to a blazed grating having a serrated cross section, a binary grating having a rectangular cross section, a holographic grating having a sinusoidal cross section, etc. is formed in a predetermined region of the molded layer  41  corresponding to a spherical region on the inner surface  34   a . For example, a reflecting film  42  including a metal evaporated film of Al, Au, etc. is formed on the molded layer  41  to cover the grating pattern  41   a . The reflecting film  42  is formed along a shape of the grating pattern  41   a . A surface of the reflecting film  42 , which is formed along the shape of the grating pattern  41   a , on the space S side serves as the dispersive part  40  in the form of a reflection grating. The molded layer  41  is formed by pressing a mold die against a molding material (e.g., photocuring epoxy resins, acrylic resins, fluorine-based resins, silicone, and replica optical resins such as organic/inorganic hybrid resins) and curing the molding material (by photocuring or thermal curing using UV light, etc.) in this state. 
     As described in the foregoing, the dispersive part  40  is provided on the inner surface  34   a  of the depression  34  in the surface  31   a  of the base wall part  31 . The dispersive part  40  has a plurality of grating grooves arranged along the reference line RL, and disperses and reflects the light L 1 , which is reflected by the second reflection part  12 , to the light detection part  22  in the space S. The dispersive part  40  is not restricted to a dispersive part directly formed in the support  30  as described above. For example, the dispersive part  40  may be provided in the support  30  by attaching a dispersive element, which has the dispersive part  40  and a substrate on which the dispersive part  40  is formed, to the support  30 . 
     Each wiring  13  has an end part (first end part)  13   a  on the light detection part  22  side, an end part (second end part)  13   b  on the opposite side from the light detection part  22  side, and a connection part  13   c . The end part  13   a  of each wiring  13  is positioned on an end surface  32   a  of each side wall part  32  to oppose each terminal  25  of the light detection element  20 . The end part  13   b  of each wiring  13  is positioned on a surface of each, projection  35  in a surface (second surface)  31   b  on the opposite side from the space S side in the base wall part  31 . The connection part  13   c  of each wiring  13  reaches the end part  13   b  from the end part  13   a  on a surface  32   b  of each side wall part  32  on the space S side, the surface  31   a  of the base wall part  31 , and an inner surface of each through hole  36 . In this way, when the wiring  13  encloses a surface of the support  30  on the space S side, deterioration of the wiring  13  may be prevented. 
     For example, the terminal  25  of the light defection element  20  and the end part  13   a  of the wiring  13  opposing each other are connected to each other by a bump  14  made of Au, solder, etc. In the spectrometer  1 A, the support  30  is fixed to the light detection element  20 , and a plurality of wirings  13  is electrically connected to the light detection part  22  of the light detection element  20  by a plurality of bumps  14 . In this way, the end part  13   a  of each wiring  13  is connected to each terminal  25  of the light detection element  20  in a fixed part of 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 light detection element  20  on the opposite side from the space S side. The cover  50  has a light transmitting member  51  and a light shielding film  52 . For example, the light transmitting member  51  is formed in a rectangular plate shape using a material which transmits the light L 1  therethrough, examples of which include silica, borosilicate glass (BK7), Pyrex (registered trademark) glass, and Kovar glass. The light shielding film  52  is formed on a surface  51   a  of the light transmitting member  51  on the space S side. A light transmitting opening  52   a  is formed in the light shielding film  52  to oppose the light passing part  21  of the light detection element  20  in the Z-axis direction. The light transmitting opening  52   a  is a slit formed in the light shielding film  52 , and extends in the Y-axis direction. In the spectrometer  1 A, an entrance NA of the light L 1  that enters the space S is defined by the light transmitting opening  52   a  of the light shielding film  52  and the light passing part  21  of the light detection element  20 . 
     When an infrared ray is detected, silicon, germanium, etc. is effective as a material of the light transmitting member  51 . In addition, the light transmitting member  51  may be provided with an AR (Anti Reflection) coat, and may have such a filter function as to transmit therethrough only a predetermined wavelength of light. Further, for example, a black resist, A 1 , etc. may be used as a material of the light shielding film  52 . Here, the black resist is effective as the material of the light shielding film  52  from a viewpoint that the zero-order light L 0  entering the zero-order light capture part  23  is inhibited from returning to the space S. 
     For example, a sealing member  15  made of resin, etc. is disposed among the surface  24   a  of the substrate  24 , the end surface  32   a  of each side wall part  32 , and the end surface  33   a  of each side wall part  33 . In addition, for example, a sealing member  16  made of glass beads, etc. is disposed inside the through hole  36  of the base wall part  31 , and the inside of the through hole  36  is filled with a sealing member  17  made of resin. In the spectrometer  1 A, the space S is airtightly sealed by a package  60 A that includes the light detection element  20 , the support  30 , the cover  50 , and the sealing members  15 ,  16 , and  17  as components. When the spectrometer  1 A is mounted on an external circuit board, the end part  13   b  of each wiring  13  functions as an electrode pad. The light passing part  21  and the zero-order light capture part  23  of the substrate  24  may be airtightly sealed by filling the light passing part  21  and the zero-order light capture part  23  of the substrate  24  with light transmitting resin in place of disposing the cover  50  on the surface  24   b  of the substrate  24 . In addition, for example, the inside of the through hole  36  of the base wall part  31  may be filled with only the sealing member  17  made of the resin without disposing the sealing member  16  made of the glass beads, etc. 
     As described in the foregoing, in the spectrometer  1 A, an optical path from the light passing part  21  to the light detection part  22  is formed inside the space S which is formed by the light detection element  20  and the support  30 . In this way, miniaturization of the spectrometer  1 A may be attempted. Further, the wiring  13  electrically connected to the light detection part  22  is provided in the support  30 , and the end part  13   b  of the wiring  13  on the opposite side from the light detection part  22  side is positioned on the surface  31   b  of the base wall part  31  on the opposite side from the space S. In this way, even when an external force acts on the end part  13   b  of the wiring  13 , the support  30  is rarely distorted. Thus, it is possible to suppress a decrease in detection accuracy (a shift of a peak wavelength in light detected by the light detection part  22 , etc.) resulting from occurrence of a variance in a positional relationship between the dispersive part  40  and the light detection part  22 . In addition, the end part  13   b  of the wiring  13  is formed on the surface  31   b  of the base wall part  31 , and thus an external force may be inhibited from acting on the light detection element  20  at the time of mounting, and damage to the light detection element  20  may be reduced when compared to a conventional art in which a circuit board is directly connected to the light detection element  20 . Therefore, the spectrometer  1 A may attempt miniaturization while suppressing a decrease in detection accuracy. 
     In addition, in the spectrometer  1 A, the depression  34  open to the space S side is formed in the base wall part  31 , and the dispersive part  40  is provided on the inner surface  34   a  of the depression  34 . In this way, it is possible to obtain the highly reliable dispersive part  40 , and to attempt miniaturization of the spectrometer  1 A. Further, even when reflected light is generated in the light detection part  22 , the reflected light may be inhibited from reaching the light detection part  22  again by a region around the depression  34  on the surface  31   a  of the base wall part  31 . Furthermore, even when an external force acts on the support  30 , an impact may be inhibited from being directly applied to the dispersive part  40  by the region around the depression  34  on the surface  31   a  of the base wall part  31 . 
     In addition, in the spectrometer  1 A, the first reflection part  11  that reflects the light L 1  passing through the light passing part  21  is provided in the support  30 , and the second reflection part  12  that reflects the light L 1 , which is reflected by the first reflection part  11 , to the dispersive part  40  is provided in the light detection element  20 . In this way, an incident direction of the light L 1  entering the dispersive part  40  and a divergence or convergence state of the light L 1  may be easily adjusted. Thus, even when the length of the optical path from the dispersive part  40  to the light detection part  22  is made short, the light L 2  dispersed by the dispersive part  40  may be accurately concentrated on a predetermined position of the light detection part  22 . 
     In addition, in the spectrometer  1 A, the end part  13   a  of the wiring  13  is connected to the terminal  25  of the light detection element  20  in the fixed part of the light detection element  20  and the support  30 . In this way, the electrical connection between the light detection part  22  and the wiring  13  may be secured. 
     In addition, in the spectrometer  1 A, a material of the support  30  is ceramic. In this way, it is possible to suppress expansion and contraction of the support  30  resulting from a temperature change of an environment in which the spectrometer  1 A is used, generation of heat in the light detection part  22 , etc. Therefore, it is possible to suppress a decrease in detection accuracy (a shift of a peak wavelength in light detected by the light, detection part  22 , etc.) resulting from occurrence of a variance in a positional relationship between the dispersive part  40  and the light detection part  22 . Since the spectrometer  1 A is miniaturized, there is concern that a slight change in an optical path may greatly affect an optical system, leading to a decrease in detection accuracy. For this reason, in particular, as described in the foregoing, when the dispersive part  40  is directly formed in the support  30 , it is significantly important to suppress expansion and contraction of the support  30 . 
     In addition, in the spectrometer  1 A, the first reflection part  11  serves as the planar mirror. In this way, when the entrance NA of the light L 1  passing through the light passing part  21  is made small, and an inequality of “the optical path length, from the light passing part  21  to the dispersive part  40 , of the light L 1  having the same spread angle as a spread angle of the light L 1  passing through the light passing part  21 ”&gt;“the optical path length from the dispersive part  40  to the light detection part  22 ” is satisfied (optical reduction system), resolving power of the light L 2  dispersed by the dispersive part  40  may be increased. Details thereof are described below. That is, when the first reflection part  11  is a planar mirror, the dispersive part  40  is irradiated with the light L 1  while the light L 1  spreads. For this reason, the entrance NA of the light L 1  passing through the light passing part  21  needs to be made small from a viewpoint that a region of the dispersive part  40  is inhibited from widening and a viewpoint that a length at which the dispersive part  40  concentrates the light L 2  on the light detection part  22  is inhibited from becoming longer. Therefore, resolving power of the light L 2  dispersed by the dispersive part  40  may be increased by reducing the entrance NA of the light L 1  and setting an optical reduction system. 
     In addition, in the spectrometer  1 A, the space S is airtightly sealed by the package  60 A that includes the light detection element  20  and the support  30  as components. In this way, it is possible to suppress a decrease in detection accuracy resulting from deterioration of a member in the space S due to moisture, occurrence of condensation in the space S due to a decrease in ambient temperature, etc. 
     In addition, in the spectrometer  1 A, the second reflection part  12  is provided in the light detection element  20 . In the light detection element  20 , the surface  24   a  of the substrate  24  on which the second reflection part  12  is formed is a flat surface. Further, the second reflection part  12  may be formed in a step of manufacturing the light detection element  20 . Thus, the second reflection part  12  according to a desired NA may be accurately formed by controlling a shape, an area, etc. of the second reflection part  12 . 
     In addition, in the spectrometer  1 A, a flat region (which may be slightly inclined) is present around the depression  34  on the surface  31   a  of the base wall part  31 . In this way, even when reflected light is generated in the light detection part  22 , the reflected light may be inhibited from reaching the light detection part  22  again. Further, when the molded layer  41  is formed on the inner surface  34   a  of the depression  34  by pressing a mold die against, resin, and when the sealing member  15  made of resin is disposed among the surface  24   a  of the substrate  24 , the end surface  32   a  of each side wall part  32 , and the end surface  33   a  of each side wall part  33 , the flat region serves as a shelter for surplus resin. In this instance, when the surplus resin is allowed to flow into the through hole  36  of the base wall part  31 , for example, the sealing member  16  made of the glass beads, etc. is unnecessary, and the resin functions as the sealing member  17 . 
     In addition, in a step of manufacturing the spectrometer  1 A, as described in the foregoing, the molded layer  41 , which is smooth, is formed on the inclined surface  37  of the base wall part  31  using a mold die, and the first reflection part  11  is formed on the molded layer  41 . Normally, a surface of the molded layer  41  is less uneven and smoother than a surface of the support  30 , and thus the first reflection part  11  having the mirror surface may be more accurately formed. However, when the first reflection part  11  is directly formed on the inclined surface  37  of the base wall part  31  without the molded layer  41  interposed therebetween, a molding material used for the molded layer  41  may be reduced, and a shape of the mold die may be simplified. Thus, the molded layer  41  may be easily formed. 
     In addition, in the spectrometer  1 A, the light passing part  21 , the first reflection part  11 , the second reflection part  12 , the dispersive part  40 , and the light detection part  22  are arranged along the reference line RL when viewed from the optical axis direction of the light L 1  passing through the light passing part  21 . Further, the dispersive part  40  has the plurality of grating grooves arranged along the reference line RL, and the light detection part  22  has live plurality of light detection channels arranged along the reference line RL. In this way, the light L 2  dispersed by the dispersive part  40  may be more accurately concentrated on each of the light detection channels of the light detection part  22 . 
     As illustrated in  FIG. 3 , for example, the cover  50  may further include a light shielding film  53  made of a black resist, Al, etc. The light shielding film  53  is formed on a surface  51   b  on the opposite side from the space S side in the light transmitting member  51 . A light transmitting opening  53   a  is formed in the light shielding film  53  to oppose the light passing part  21  of the light detection element  20  in the Z-axis direction. The light transmitting opening  53   a  is a slit formed in the light shielding film  53 , and extends in the Y-axis direction. In this case, the entrance NA of the light L 1  entering the space S may be more accurately defined using the light transmitting opening  53   a  of the light shielding film  53 , the light transmitting opening  52   a  of the light shielding film  52 , and the light passing part  21  of the light detection element  20 . 
     In addition, as illustrated in  FIG. 4 , the cover  50  may further include the above-described light shielding film  53 , and a light transmitting opening  52   b  may be formed in the light shielding film  52  to oppose the zero-order light capture part  23  of the light detection element  20  in the Z-axis direction. In this case, it is possible to more reliably inhibit the zero-order light L 0  entering the zero-order light capture part  23  from returning to the space S. 
     In addition, when the spectrometer  1 A is produced, the support  30  provided with the wiring  13 , the first reflection part  11 , and the dispersive part  40  is prepared (first step), the light detection element  20  provided with the light passing part  21 , the second reflection part  12 , and the light detection part  22  is prepared (second step), and then the optical path from the light passing part  21  to the light detection part  22  is formed in the space S, and the wiring  13  is electrically connected to the light detection part  22  by fixing the support  30  to the light, detection element  20  such that the space S is formed (third step). As described above, the optical path from the light passing part  21  to the light detection part  22  is formed in the space S, and the wiring  13  is electrically connected to the light detection part  22  only by fixing the support  30  to the light detection element  20 . Therefore, according to a method for manufacturing the spectrometer  1 A, it is possible to easily produce the spectrometer  1 A which can attempt miniaturization while suppressing a decrease in detection accuracy. The step of preparing the support  30  and the step of preparing the light detection element  20  may be implemented in an arbitrary order. 
     In particular, when the spectrometer  1 A is produced, in addition to the electrical connection between the wiring  13  and the light detection part  22 , fixing of the support  30  to the light detection element  20  and formation of the optical path from the light passing part  21  to the light detection part  22  are implemented only by connecting the end part  13   a  of the wiring  13  provided in the support  30  to the terminal  25  of the light detection element  20 . 
     Second Embodiment 
     As illustrated in  FIGS. 5 and 6 , a spectrometer  1 B is mainly different from the above-described spectrometer  1 A in that a first reflection part  11  is a concave mirror. In the spectrometer  1 B, the first reflection part  11  is provided in a spherical region on an inner surface  34   a  of a depression  34  of a base wall part  31  with a molded layer  41  interposed therebetween. For example, the first reflection part  11  is a concave mirror which is made of a metal evaporated film of Al, Au, etc. and has a mirror surface, and reflects light L 1  passing through a light passing part  21  to a second reflection part  12  in a space S. The first reflection part  11  may be directly formed on the inner surface  34   a  of the depression  34  in a support  30  without the molded layer  41  interposed therebetween. In addition, a cover  50  may have a configuration illustrated in  FIG. 3  and  FIG. 4 . 
     According to the spectrometer  1 B configured as described above, it is possible to attempt miniaturization while suppressing a decrease in detection accuracy due to a similar reason to that in the above-described spectrometer  1 A. Further, in the spectrometer  1 B, the first reflection part  11  is the concave mirror. In this way, a spread angle of the light L 1  is suppressed by the first reflection part  11 , and thus the entrance NA of the light L 1  passing through a light passing part  21  may be increased to increase sensitivity, and the length of an optical path from a dispersive part  40  to a light detection part  22  may be further decreased to further miniaturize the spectrometer  1 B. Details thereof are described below. That is, when the first reflection part  11  is the concave mirror, the dispersive part  40  is irradiated with the light L 1  while the light L 1  is approximately collimated. For this reason, a distance at which the dispersive part  40  concentrates light L 2  on the light detection part  22  is short when compared to a case in which the dispersive part  40  is irradiated with the light L 1  while the light L 1  spreads. Therefore, the entrance NA of the light L 1  may be increased to increase sensitivity, and the optical path length from the dispersive part  40  to the light detection part  22  may be further decreased to further miniaturize the spectrometer  1 B. 
     Third Embodiment 
     As illustrated in  FIGS. 7 and 8 , a spectrometer  1 C is mainly different from the above-described spectrometer  1 A in that a space S is airtightly sealed by a package  60 B that accommodates a light detection element  20  and a support  30 . The package  60 B includes a stem  61  and a cap  62 . For example, the stem  61  is formed in a disc shape using metal. For example, the cap  62  is formed in a cylindrical shape using metal. The stem  61  and the cap  62  are airtightly joined to each other while a flange part  61   a  provided on an outer edge of the stem  61  and a flange part  62   a  provided at an opening end of the cap  62  are in contact, with each other. By way of example, the stem  61  and the cap  62  are airtightly sealed to each other in a nitrogen atmosphere under dew point management (e.g., at −55° C.) or an atmosphere subjected to vacuum drawing. 
     A light entrance part  63  is provided on a wall part  62   b  of the cap  62  opposing the stem  61  to oppose a light passing part  21  of a light detection element  20  in a Z-axis direction. The light entrance part  63  is configured by airtightly joining a window member  64  to an inner surface of the wall part  62   b  to cover a light transmission hole  62   c  formed in the wall part  62   b . The light transmission hole  62   c  has a shape including the light passing part  21  when viewed in the Z-axis direction. For example, the window member  64  is formed in a plate shape using a material which transmits light L 1  therethrough, examples of which include silica, borosilicate glass (BK7), Pyrex (registered trademark) glass, and Kovar glass. In the spectrometer  1 C, the light L 1  enters the light passing part  21  through the light entrance part  63  from the outside of the package  60 B. When an infrared ray is detected, silicon, germanium, etc. is effective as a material of the window member  64 . In addition, the window member  64  may be provided with an AR coat, and may have such a filter function as to transmit therethrough only a predetermined wavelength of light. Further, at least a portion of the window member  64  may be disposed inside the light transmission hole  62   c  such that an outer surface of the window member  64  and an outer surface of the wall part  62   b  are flush with each other. 
     A plurality of through holes  61   b  is formed in the stem  61 . Lead pins  65  are inserted into the respective through holes  61   b . For example, each of the lead pins  65  is airtightly fixed to each of the through, holes  61   b  through a hermetic seal made of sealing glass such as low-melting glass having electrically-insulating and light-shielding properties. An end part inside the package  60 B in each of the lead pins  65  is connected to an end part  13   b  of each wiring  13  provided in the support  30  on a surface  31   b  of a base wall part  31 . In this way, electrical connection between the lead pin  65  and the wiring  13  corresponding to each other, and positioning of the light detection element  20  and the support  30  with respect to the package  608  are achieved. 
     The end part inside the package  60 B in the lead pin  65  may be connected to the end part  13   b  of the wiring  13  extending inside a through hole formed in the base wall part  31  or inside a depression formed on the surface  31   b  of the base wall part  31  while being disposed inside the through hole or inside the depression. In addition, the end part inside the package  60 B in the lead pin  65  and the end part  13   b  of the wiring  13  may be electrically connected to each other through a circuit board on which the support  30  is mounted by bump bonding, etc. In this case, the end part inside the package  60 B in the lead pin  65  may be disposed to surround the support  30  when viewed in a thickness direction of the stem  61  (that is, the Z-axis direction). In addition, the circuit board may be disposed in the stem  61  while touching the stem  61 , or may be supported by the plurality of lead pins  65  while being separated from the stem  61 . 
     In the spectrometer  1 C, for example, a substrate  24  of the light detection element  20  and the base wall part  31  of the support  30  are formed in hexagonal plate shapes. Further, the light detection element  20  and the support  30  are accommodated in the package  608 . Thus, in the spectrometer  1 C, a connection part  13   c  of each wiring  13  may not be enclosed on a surface  32   b  of each side wall part  32  on the space S side, a surface  31   a  of the base wall part  31 , and an inner surface of each through hole  36  as in the above-described spectrometer  1 A. In the spectrometer  1 C, the connection part  13   c  of each wiring  13  reaches the end part  13   b  from an end part  13   a  on a surface of each side wall part  32  on the opposite side from the space S side and the surface  31   b  of the base wall part  31 . In this way, when the wiring  13  is enclosed on a surface of the support  30  on the opposite side from the space S side, scattering of light due to the wiring  13  exposed to the space S may be prevented. Further, in the spectrometer  1 C, sealing members  15 ,  16 , and  17  may not be disposed, and a cover  50  may not be provided as in the above-described spectrometer  1 A. 
     According to the spectrometer  1 C configured as described above, it is possible to attempt miniaturization while suppressing a decrease in detection accuracy due to a similar reason to that in the above-described spectrometer  1 A. In addition, in the spectrometer  1 C, the space S is airtightly sealed by the package  60 B that accommodates the light detection element  20  and the support  30 . In this way, it is possible to suppress a decrease in detection accuracy resulting from deterioration of a member in the space S due to moisture, occurrence of condensation in the space S due to a decrease in ambient temperature, etc. 
     In addition, in the spectrometer  1 C, a gap is formed among an end surface  32   a  of each side wall part  32  of the support  30 , an end surface  33   a  of each side wall part  33 , and a surface  24   a  of the substrate  24  of the light detection element  20 . In this way, deformation of the light detection element  20  rarely affects the support  30 , and deformation of the support  30  rarely affects the light detection element  20 , and thus an optical path from the light passing part  21  to the light detection part  22  may be accurately maintained. 
     In addition, in the spectrometer  1 C, the support  30  is supported by the plurality of lead pins  65  while being separated from the stem  61 . In this way, deformation of the stem  61 , an external force from the outside of the package  60 B, etc. rarely affect the support  30 , and thus the optical path from the light passing part  21  to the light detection part  22  may be accurately maintained. 
     Fourth Embodiment 
     As illustrated in  FIGS. 9 and 10 , a spectrometer  1 D is mainly different from the spectrometer  1 C in that a first reflection part  11  is a concave mirror. In the spectrometer  1 D, the first reflection part  11  is provided in a spherical region on an inner surface  34   a  of a depression  34  of a base wall part  31  with a molded layer  41  interposed therebetween. For example, the first reflection part  11  is a concave mirror made of a metal evaporated film of Al, Au, etc., and reflects light L 1  passing through a light passing part  21  to a second reflection part  12  in a space S. 
     According to the spectrometer  1 D configured as described above, it is possible to attempt miniaturization while suppressing a decrease in detection accuracy due to a similar reason to that in the above-described spectrometer  1 A. Further, in the spectrometer  1 D, the first reflection part  11  is the concave mirror. In this way, a spread angle of the light L 1  is suppressed by the first reflection part  11 , and thus the entrance NA of the light L 1  passing through the light passing part  21  may be increased to increase sensitivity, and the length of an optical path from a dispersive part  40  to a light detection part  22  may be further decreased to further miniaturize the spectrometer  1 B. In addition, in the spectrometer  1 D, the space S is airtightly sealed by a package  60 B that accommodates a light detection element  20  and a support  30 . In this way, it is possible to suppress a decrease in detection accuracy resulting from deterioration of a member in the space S due to moisture, occurrence of condensation in the space S due to a decrease in ambient temperature, etc. 
     [Relationship Between Miniaturization of Spectrometer and Radius of Curvature of Dispersive Part] 
     As illustrated in  FIG. 11 , in a spectrometer of  FIG. 11( a )  and a spectrometer of  FIG. 11( b ) , light L 1  passing through a light passing part  21  directly enters a dispersive part  40 , and light L 2  dispersed and reflected by the dispersive part  40  directly enters a light detection part  22 . In a spectrometer of  FIG. 11( c ) , the light L 1  passing through the light passing part  21  is reflected by a first reflection part  11  and a second reflection part  12  in sequence, and enters the dispersive part  40 , and the light L 2  dispersed and reflected by the dispersive part  40  directly enters the light detection part  22 . In the spectrometer of  FIG. 11( a ) , the radius of curvature of an inner surface  34   a  on which the dispersive part  40  is formed is 6 mm. In the spectrometer of  FIG. 11( b ) , the radius of curvature of the inner surface  34   a  on which the dispersive part  40  is formed is 3 mm. In the spectrometer of  FIG. 11( c ) , the radius of curvature of the inner surface  34   a  on which the first reflection part  11  and the dispersive part  40  are formed is 4 mm. 
     First, the spectrometer of  FIG. 11( a )  and the spectrometer of  FIG. 11( b )  are compared. The height (height in a Z-axis direction) of the spectrometer of  FIG. 11( b )  a lower than the height of the spectrometer of  FIG. 11( a )  since a distance at which the dispersive part  40  concentrates the light L 2  on the light detection part  22  becomes shorter as the radius of curvature of the inner surface  34   a  on which the dispersive part  40  is formed becomes smaller. 
     However, as the radius of curvature of the inner surface  34   a  on which the dispersive part  40  is formed is made smaller, various problems occur as below. That is, a focus line of the light L 2  (a line connecting positions on which the light L 2  having different wavelengths is concentrated) is easily distorted. In addition, influence of various aberrations becomes great, and thus them is difficulty in making correction by designing a grating. Further, in particular, the angle of diffraction to a long wavelength, side becomes excessive, and thus a grating pitch needs to be narrowed. However, when the grating pitch becomes narrow, there is difficulty in forming a grating. Furthermore, blazing is necessary to increase sensitivity. However, when the grating pitch is narrowed, there is difficulty in blazing. In addition, in particular, the angle of diffraction to the long wavelength side becomes excessive, and thus it is disadvantageous in terms of resolving power of the light L 2 . 
     The above-mentioned various problems occur since it is practical to configure the light passing part  21  such that, the light L 1  passes in a direction perpendicular to surfaces  24   a  and  24   b  of a substrate  24  of a light detection element  20  when the light passing part  21  is provided as a slit on the substrate  24 . In addition, the problems occur since there is a restriction that zero-order light L 0  should be reflected on the opposite side to the light detection part  22  side. 
     On the other hand, in the spectrometer of  FIG. 11( c ) , even though tire radius of curvature of the inner surface  34   a  on which the first reflection part  11  and the dispersive part  40  are formed is 4 mm, the height of the spectrometer of  FIG. 11( c )  is lower than the height of the spectrometer of  FIG. 11( b )  since an incident direction of the light L 1  entering the dispersive part  40  and a divergence or convergence state of the light L 1  may be adjusted using the first reflection part  11  and the second reflection part  12  in the spectrometer of  FIG. 11( c ) . 
     As described in the foregoing, it is practical to configure the light passing part  21  such that the light L 1  passes in the direction perpendicular to the surfaces  24   a  and  24   b  of the substrate  24  of the light detection element  20  when the light passing part  21  is provided as a slit on the substrate  24 . In this case, when the first reflection part  11  and the second reflection part  12  are used, miniaturization of the spectrometer may be attempted. In the spectrometer of  FIG. 11( c ) , the fact that the zero-order light L 0  can be captured by a zero-order light capture part  23  which is positioned between the second reflection part  12  and the light detection part  22  is a great feature in attempting miniaturization of the spectrometer while suppressing a decrease in detection accuracy of the spectrometer. 
     [Superiority in Optical Path from Dispersive Part to Light Detection Part] 
     First, a spectrometer will be examined. Here, as illustrated in  FIG. 12 , the spectrometer adopts an optical path that reaches a light detection part  22  from a light passing part  21  via a first reflection part  11 , a dispersive part  40 , and a second reflection part  12  in sequence. In the spectrometer of  FIG. 12 , light L 1  is dispersed and reflected by the dispersive part  40  which is a planar grating. Then, light L 2  dispersed and reflected by the dispersive part  40  is reflected by the second reflection part  12  which is a concave mirror, and enters the light defection part  72 . In this case, respective rays of the light L 2  enter the light detection part  22  such that, positions, on which the respective rays of the light L 2  are concentrated, are close to one another. 
     In the spectrometer of  FIG. 12 , when a wavelength range of detected light L 2  is attempted to be widened, the radius of curvature of the inner surface  34   a  on which the dispersive part  40  is formed and a distance between the second reflection part  12  and the light detection part  22  need to be increased. Further, since the respective rays of the light L 2  enter the light detection part  22  such that positions, on which the respective rays of the light L 2  are concentrated, are close to one another, the radius of curvature of the inner surface  34   a  and the distance between the second reflection part  12  and the light detection part  22  need to be increased. When a distance between the positions, on which the respective rays of the light L 2  are concentrated, is excessively widened by narrowing a grating pitch (a distance between grating grooves), there is difficulty in adjusting a focus line of the light L 2  to the light detection part  22 . In this way, the optical path, which reaches the light detection part  22  from the light passing part  21  via the first reflection part  11 , the dispersive part  40 , and the second reflection part  12  in sequence, can be regarded as an unfit optical path for miniaturization. 
     On the other hand, as illustrated in  FIG. 11( c ) , in the spectrometer that adopts an optical path that reaches the light detection part  22  from the light passing part  21  via the first reflection part  11 , the second reflection part  12 , and the dispersive part  40  in sequence (that is, a spectrometer corresponding to the spectrometer  1 A to  1 D described above), respective rays of light L 2  enter the light detection part  22  such that positions, on which the respective rays of the light L 2  are concentrated, are separated from one another. Therefore, the optical path that reaches the light detection part  22  from the light passing part  21  via the first reflection part  11 , the second reflection part  12 , and the dispersive part  40  in sequence can be regarded as a suitable optical path for miniaturization. The above description can be understood from the fact that the radius of curvature of the inner surface  34   a  is 4 mm, and the height (height in the Z-axis direction) is about 2 mm in the spectrometer of  FIG. 11( c )  while the radius of curvature of the inner surface  34   a  is 12 mm, and the height, is 7 mm in the spectrometer of  FIG. 12 . 
     Hereinbefore, the first to fourth embodiments of the invention have been described. However, the invention is not restricted to the above respective embodiments. For example, even though the entrance NA of the light L 1  entering the space S is defined by the shapes of the light passing part  21  of the light detection element  20  and the light transmitting opening  52   a  of the light shielding film  52  (the light transmitting opening  53   a  of the light shielding film  53  depending on cases) in the first and second embodiments, the entrance NA of the light L 1  entering the space S may be practically defined by adjusting a shape of a region of at least one of the first reflection part  11 , the second reflection part  12 , and the dispersive part  40 . The light L 2  entering the light detection part  22  is diffracted light, and thus the entrance NA may be practically defined by adjusting a shape of a predetermined region in which the grating pattern  41   a  is formed in the molded layer  41 . 
     In addition, even though the terminal  25  of the light detection element  20  and the end part  13   a  of the wiring  13  opposing each other are connected to each other by the bump  14  in the above respective embodiments, the terminal  25  of the light detection element  20  and the end part  13   a  of the wiring  13  opposing each other may be connected to each other by soldering. Further, the terminal  25  of the light detection element  20  and the end part  13   a  of the wiring  13  opposing each other may be connected to each other on the end surface  33   a  of each side wall part  33  of the support  30  rather than only on the end surface  32   a  of each side wall part  32  of the support  30 . Alternatively, the terminal  25  and the end part  13   a  may be connected to each other on the end surface  32   a  of each side wall part  32  and the end surface  33   a  of each side wall part  33  of the support  30 . Furthermore, in the spectrometers  1 A and  1 B, the wiring  13  may be enclosed on a surface on the opposite side from the space S side in the support  30 . In addition, in the spectrometers  1 C and  1 D, the wiring  13  may be enclosed on a surface on the space S side in the support  30 . 
     In addition, the material of the support  30  is not restricted to ceramic, and another molding material, for example, resin such as LCP, PPA, and epoxy, and glass for molding may be used as the material. Further, the package  60 B may have a shape of a rectangular parallelepiped box. Furthermore, when the space S is airtightly sealed by the package  60 B that accommodates the light, detection element  20  and the support  30 , the support  30  may have a plurality of pillar parts or a plurality of side wall parts separated from one another in place of the pair of aide wall parts  32  and the pair of side wall parts  33  which surround the space S. In this way, materials and shapes of respective components of the spectrometers  1 A to  1 D are not restricted to the above-described materials and shapes, and various materials and shapes may be applied thereto. 
     In addition, in the spectrometers  1 A,  1 B,  1 C, and  1 D, the light L 1  passing through the light passing part  21  may be directly let into the dispersive part  40 , and the light L 2  dispersed and reflected by the dispersive part  40  may be directly let into the light detection part  22  without using the first reflection part  11  and the second reflection part  12 . Even in this case, it is possible to sufficiently miniaturize the dispersive part while suppressing a decrease in detection accuracy of the spectrometer. 
     In addition, the end part  13   b  of the wiring  13  may be positioned in the region around the depression  34  on the surface  31   a  of the base wall part  31  when viewed in a thickness direction of the base wall part  31  (that is the Z-axis direction). In this case, it is possible to inhibit the dispersive part  40  from being deformed due to an external force acting on the end part  13   b  of the wiring  13 . 
     INDUSTRIAL APPLICABILITY 
     The invention can provide a spectrometer which can attempt miniaturization while suppressing a decrease in detection accuracy, and a method for manufacturing a spectrometer capable of easily manufacturing such a spectrometer. 
     REFERENCE SIGNS LIST 
       1 A,  1 B,  1 C,  1 D: spectrometer;  11 : first reflection part;  12 : second reflection part;  13 : wiring;  13   a : end part (first end part);  13   b : end part (second end part);  20 : light detection element;  21 : light passing part;  22 : light detection part;  25 : terminal;  30 : support;  31 ; base wall part;  31   a : surface (first surface);  31   b : surface (second surface);  34 ; depression;  34   a : inner surface;  40 : dispersive part;  60 A,  60 B: package; S: space; RL: reference line.