JP5825880B2 - Spectroscopic module - Google Patents

Description

  The present invention relates to a spectroscopic module that spectrally detects light.

  As a conventional spectroscopic module, for example, Patent Document 1 includes a support in which a light incident slit is formed, a light detection element disposed on the support, and a casing provided with a spherical imaging grating. A spectrometer is described in which a casing is attached to a support so that a spherical imaging grating faces the light entrance slit and the light detection element.

JP-T-2006-514277

  However, in the above-described spectrometer, if the distance between the light incident slit and the light detection element is shortened in order to further reduce the size, a part of the light passing through the light incident slit is light as stray light. It may be detected by the detection element, and the detection accuracy as a spectrometer may be reduced.

  Therefore, an object of the present invention is to provide a spectroscopic module that can achieve both reduction in size and improvement in detection accuracy.

The spectroscopic module of the present invention is disposed on a predetermined surface, a main body that transmits light, a spectroscopic unit that splits light incident on the main body from a predetermined surface of the main body and reflects the light to a predetermined surface, A light detection element that detects light that is split and reflected by the spectroscopic unit, a first light passage hole that is provided on a predetermined surface and through which light traveling to the spectroscopic unit passes, and from the spectroscopic unit to the photodetection element A light-shielding layer having a second light passage hole through which traveling light passes, and a light-shielding resin member that fixes the light detection element to a predetermined surface, and the resin member is viewed from the incident direction of light A plurality of protrusions protruding from the outer edge of the light detection element, and the entire first light passage hole is adjacent to the outer side of the outer edge of the light detection element when viewed from the light incident direction. is positioned between the light detecting element, when viewed from the incident direction of light, The protrusions adjacent to each other are formed in a rectangular shape, and are located at the corners adjacent to each other through the short side of the light detection element. In the direction parallel to the short side, the length of the first light passage hole Also, the length of the light detection portion of the light detection element is increased .

In this spectroscopic module, the light detection element is fixed to a predetermined surface of the main body by a light-blocking resin member, and the entire first light passage hole of the light-blocking layer provided on the predetermined surface is light-blocking. It is located between the protrusions which the resin member has. Accordingly, the first light passage hole can be disposed close to the light detection element without being obstructed by the resin member for fixing the light detection element. Furthermore, even if the first light passage hole is disposed close to the light detection element, the protruding portion located so as to sandwich the entire first light passage hole has a light shielding property. A part of the light passing through the passage hole can be prevented from entering the light detection element as stray light. Therefore, according to this spectroscopic module, it is possible to achieve both reduction in size and improvement in detection accuracy.

  In addition, the first light passage hole may be a light incident slit that extends in a direction in which adjacent protrusions are arranged. According to this configuration, the entire first light passage hole can be disposed close to the light detection element, and further miniaturization can be achieved.

  Moreover, the resin member may further have a connection portion that connects adjacent protrusions along the outer edge of the light detection element. In this structure, the connection part which connects adjacent protrusion parts also has light-shielding property. Therefore, according to this structure, it can suppress more reliably that a part of light which passes the 1st light passage hole enters into a photon detection element as stray light, and aims at the improvement of a further detection accuracy. It becomes possible.

Further, each of the protruding portions fit Ri neighbor may project along a line extending at 135 ° an angle less than 90 ° or more with respect to the short side from the respective corners adjacent. For example, when the light detection element is deformed (expanded / contracted) due to a temperature change, the deformation of the light detection element in the longitudinal direction is relatively large. In this configuration, however, the light detection element is moved in the longitudinal direction. The strength for suppressing the deformation of the protrusion is high at the protruding portion. Therefore, according to this configuration, it is possible to reduce the positional deviation between the first light passage hole and the light detection element, and it is possible to suppress deterioration in detection accuracy due to deformation of the light detection element.

  According to the present invention, in the spectroscopic module, both miniaturization and improvement in detection accuracy can be achieved.

It is a top view of the spectroscopy module of one embodiment of the present invention. It is sectional drawing of the spectroscopy module along the II-II line | wire of FIG. It is a figure which shows arrangement | positioning of the resin member in the spectroscopy module of other embodiment of this invention. It is a figure which shows arrangement | positioning of the resin member in the spectroscopy module of other embodiment of this invention.

  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 an equivalent part, and the overlapping description is abbreviate | omitted.

  As shown in FIGS. 1 and 2, the spectroscopic module 1 includes a main body 2 that transmits light, and light L1 incident on the main body 2 from the front surface (predetermined surface) 2a of the main body 2 and the front surface 2a. And a photodetecting element 4 that is disposed on the front surface 2a and detects the light L2 that is split and reflected by the spectroscopic unit 3. The spectroscopic module 1 measures the wavelength distribution of the light L1, the intensity of a specific wavelength component, etc. by splitting the light L1 into a plurality of light L2 by the spectroscopic unit 3 and detecting the light L2 by the light detecting element 4. It is.

  The spectral module 1 further includes a light shielding layer 6 provided on the front surface 2a of the main body 2 and a light shielding resin member 10 that fixes the light detection element 4 to the front surface 2a. The light shielding layer 6 includes a light incident slit (first light passage hole) 6a through which light L1 traveling from the outside to the spectroscopic unit 3 passes and a light passage through which light L2 traveling from the spectroscopic unit 3 to the light detection element 4 passes. An opening (second light passage hole) 6b is provided. The resin member 10 is made of a light-absorbing resin material (epoxy-based, acrylic-based, silicone-based, urethane-based resin, organic / inorganic hybrid resin, or a resin in which a light-absorbing pigment is mixed).

The main body 2 includes light transmitting members 2 ₁ to 2 ₃ stacked in the incident direction of the light L1 (here, a direction substantially perpendicular to the front surface 2a). The light transmitting members 2 ₁ and 2 ₂ are formed in a rectangular plate shape by using light transmitting glass such as BK7, Pyrex (registered trademark), or quartz. Light transmitting member 2 _3, the light transmitting member 2 _1, 2 ₂ of the same material, transparent resin, light-transmissive inorganic-organic hybrid materials, or hemispherical shape by light-transmissive low-melting glass for replica molding Is formed. When the light transmitting member 2 ₃ made of a light transmitting member 2 _1, 2 ₂ of the same material, the light transmitting member 2 ₃ is bonded to the light transmitting member 2 ₂ by an optical resin or direct bonding. Incidentally, the outer surface of the light transmitting member 2 ₃ functions as a lens for focusing the light L2 to the light detecting portion 40 of the light detecting element 4 is reflected while being split by the spectroscopic portion 3.

Spectroscopic portion 3 is a reflection type grating has light-transmitting member 2 ₃ diffraction layer formed on the outer surface 14, and a reflective layer 5 formed on the outer surface of the diffracting layer 14. Diffracting layer 14 is blazed gratings serrated cross section, a binary grating rectangular cross section, a holographic grating or the like of the sinusoidal cross-section, for example, a photosensitive resin is applied to the outer surface of the light transmitting member 2 _3, It is formed by UV-curing a photosensitive resin using a light-transmitting mold (grating mold) made of quartz or the like. The diffraction layer 14 becomes a more stable material when heated and cured after UV curing. The reflective layer 5 is in the form of a film, and is formed, for example, by evaporating Al, Au, or the like on the outer surface of the diffraction layer 14. The material of the diffractive layer 14 is not limited to a photosensitive resin, and may be a photosensitive glass, a photosensitive inorganic / organic hybrid material, or a resin, glass or inorganic / organic hybrid material that is deformed by heat. Also good.

The light detection element 4 is a photodiode array, and includes a light detection unit 40 in which long photodiodes are arranged one-dimensionally in a direction substantially perpendicular to the longitudinal direction. The light detection element 4 is arranged so that the one-dimensional arrangement direction of the photodiodes substantially coincides with the longitudinal direction of the light transmitting members 2 ₁ and 2 ₂ and the light detection unit 40 faces the front surface 2 a side of the main body 2. . The light detection element 4 is not limited to a photodiode array, and may be a C-MOS image sensor, a CCD image sensor, or the like.

(Here, the front surface of the light transmitting member _{2 1)} the front plane 2a of the body portion 2, the single-layer film such as Al or Au, or Ti-Pt-Au, Cr- Pt-Au, Ti-Ni-Au, Cr A wiring 9 made of a laminated film such as -Au is formed. The wiring 9 includes a plurality of pad portions 9a disposed around the light passage opening 6b, a plurality of pad portions 9b disposed at one end portion in the longitudinal direction of the light transmitting members 2 ₁ and 2 ₂ , and a corresponding pad portion 9a. And a plurality of connecting portions 9c that connect the pad portions 9b. An external terminal of the light detection element 4 is electrically connected to the pad portion 9a by flip chip bonding via a bump 18. A flexible printed board 11 for taking out the output signal of the light detection element 4 to the outside is electrically connected to the pad portion 9b by wire bonding. Further, a light reflection preventing layer 13 made of a single layer film such as CrO or a laminated film such as Cr—CrO is formed on the front surface 2 a side of the wiring 9. Thereby, irregular reflection of stray light by the wiring 9 is prevented.

The light shielding layer 6 is provided on the front surface 2a of the main body 2 so as to cover the connection portion 9c of the wiring 9 and expose the pad portions 9a and 9b of the wiring 9. The light incident slit 6a of the light shielding layer 6 extends in a direction substantially perpendicular to the longitudinal direction of the light transmitting members 2 ₁ and 2 ₂ . The light passage opening 6 b of the light shielding layer 6 faces the light detection unit 40 of the light detection element 4. The light shielding layer 6 is patterned so as to have a light incident slit 6a and a light passage opening 6b, and is integrally formed of a light absorbing material (CrO, a laminated film containing CrO, or a black resist).

Note that an electrical insulating layer made of SiO ₂ , SiN, SiON, or the like may be formed in a film shape on the surface of the wiring 9 opposite to the front surface 2a. For example, when the light shielding layer 6 is made of a black resist, since the light shielding layer 6 contains carbon, the black resist may be altered by the influence of heat or the like to have conductivity. At this time, if an electrical insulating layer is formed, it is possible to prevent a short circuit between the wirings 9 and 9.

A light shielding layer 7 is formed between the light transmitting members 2 ₁ and 2 ₂ adjacent to each other in the incident direction of the light L1. The light shielding layer 7 has a light passage opening 7a through which light L1 traveling to the spectroscopic unit 3 passes, and a light passage opening 7b through which light L2 traveling from the spectroscopic unit 3 to the light detection element 4 passes. Shielding layer 7 is formed on the rear surface of the light transmitting member 2 _1, the light blocking layer 7 light transmitting member 2 ₁ is formed and the light transmitting member 2 ₂ is bonded by an optical resin material 8 for refractive index matching Are combined. The light shielding layer 7 is patterned to have the light passage openings 7a and 7b, and is integrally formed of a light absorbing material (a laminated film containing CrO, CrO, or a black resist). By providing the light shielding layer 7 in this manner, the lights L1 and L2 traveling through the main body 2 while being spread are restricted so as to reach a desired region, and the incidence of stray light on the light detection element 4 is suppressed. The

  As shown in FIG. 1, the resin member 10 has protrusions 15 a and 15 b. The protrusions 15a and 15b have an outer edge (that is, the short side 4a of the light detection element 4) formed in a substantially rectangular shape (for example, about 2 mm × 8 mm) when viewed from the incident direction of the light L1. And protrudes outward from the long side 4b).

  The protrusion 15a is located at each of the corners 4c and 4c adjacent to each other via the short side 4a on the light incident slit 6a side. The protrusion 15b is located at each of the corners 4c and 4c adjacent to each other via the short side 4a opposite to the light incident slit 6a. The protrusions 15a and 15b cover the bump 18 at each corner 4c (see FIG. 2). Thus, the resin member 10 serves as a reinforcing member for the bump 18 that supports the light detection element 4 on the front surface 2 a of the main body 2 and fixes the light detection element 4 to the front surface 2 a of the main body 2.

  Each of the adjacent protrusions 15a and 15a extends along a line extending at an angle of 90 ° to 135 ° with respect to the short side 4a on the light incident slit 6a side (a line indicated by a one-dot chain line in FIG. 1). And protrude from each of the adjacent corners 4c, 4c. Similarly, each of the adjacent protrusions 15b, 15b is adjacent to the corner portion along a line extending at an angle of 90 ° to 135 ° with respect to the short side 4a opposite to the light incident slit 6a. It protrudes from each of 4c and 4c.

  The light incident slit 6a formed in the light shielding layer 6 extends in a direction in which adjacent protrusions 15a and 15a are arranged (here, a direction substantially parallel to the short side 4a) and is viewed from the incident direction of the light L1. Are located between the adjacent protrusions 15a, 15a. In the extending direction of the light incident slit 6a, the length of the light incident slit 6a is, for example, 0.5 mm to 1 mm, and the length of the light detection unit 40 of the light detection element 4 is, for example, about 1 mm. In the extending direction of the light incident slit 6a, if the length of the light detection unit 40 is larger than the length of the light incident slit 6a, the width of the light L2 imaged on the light detection unit 40 by the spectroscopic unit 3 is increased. Even if it becomes large or a slight shift occurs in the image forming position of the light L2 with respect to the light detection unit 40, the light L2 reliably enters the light detection unit 40, and a decrease in detection sensitivity is prevented.

In the spectroscopic module 1 configured as described above, the light L1 enters the main body 2 from the front surface 2a of the main body 2 through the light incident slit 6a of the light shielding layer 6. Light L1 having entered the main unit 2, the light transmitting member 2 _1, the light passage opening 7a of the light shielding layer 7, and travels on the optical transmitting member 2 _2, 2 ₃ reaches the spectroscopic unit 3, it is dispersed by the spectroscopic portion 3 And reflected to the front surface 2a side of the main body 2. The light L2 that is split and reflected by the spectroscopic unit 3 travels through the light transmitting members 2 ₃ and 2 ₂ , the light passage opening 7b of the light shielding layer 7, the light transmission member 2 ₁ , and the light passage opening 6b of the light shielding layer 6. Then, the light reaches the light detection unit 40 of the light detection element 4 and is detected by the light detection element 4.

  As described above, in the spectroscopic module 1, the light detection element 4 is fixed to the front surface 2a of the main body 2 by the light-shielding resin member 10, and the light incident slit 6a of the light-shielding layer 6 provided on the front surface 2a. However, it is located between the protrusions 15a and 15a in a state where the protrusions 15a and 15a of the light-shielding resin member 10 extend in the direction in which the light-shielding resin members 10 are arranged. Accordingly, the entire light incident slit 6 a can be disposed close to the light detection element 4 without being obstructed by the resin member 10 for fixing the light detection element 4. Furthermore, even if the entire light incident slit 6a is arranged close to the light detection element 4, the protrusions 15a and 15a positioned so as to sandwich the light incident slit 6a have a light shielding property, and therefore the light incident slit 6a. It is possible to prevent a part of the light L1 passing through the light from entering the light detection element 4 as stray light. Therefore, according to the spectroscopic module 1, it is possible to achieve both reduction in size and improvement in detection accuracy.

  The light detecting element 4 is formed in a substantially rectangular shape when viewed from the incident direction of the light L1. And the adjacent protrusion parts 15a and 15a are located in the corner | angular parts 4c and 4c adjacent via the short side 4a by the side of the light-incidence slit 6a, and each of the adjacent protrusion parts 15a and 15a is an adjacent corner | angular. Each of the portions 4c and 4c protrudes along a line extending at an angle of 90 ° to 135 ° with respect to the short side 4a. Similarly, the adjacent protrusions 15b and 15b are located at the corners 4c and 4c adjacent via the short side 4a opposite to the light incident slit 6a, and the adjacent protrusions 15b and 15b are respectively Each of the adjacent corners 4c, 4c protrudes along a line extending at an angle of 90 ° to 135 ° with respect to the short side 4a. For example, when the light detection element 4 is deformed (expanded / contracted) due to a temperature change, the deformation in the longitudinal direction of the light detection element 4 is relatively large. The strength that suppresses deformation in the longitudinal direction is higher in the protruding portion 15a and the protruding portion 15b. Therefore, according to this configuration, it is possible to reduce the positional deviation between the light incident slit 6a and the light detection element 4, and it is possible to suppress the deterioration of detection accuracy due to the deformation of the light detection element 4. Such a reduction in the positional deviation in the longitudinal direction of the photodetecting element 4 is a reduction in the positional deviation in the one-dimensional arrangement direction of the photodiodes in the photodetecting section 40. It is extremely important.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to said each embodiment. For example, as shown in FIG. 3, adjacent protrusions 15 a and 15 a may be connected by a connection portion 16 along the outer edge of the light detection element 4 (here, the short side 4 a on the light incident slit 6 a side). Good. In this case, since the connecting portion 16 that connects the adjacent protruding portions 15a and 15a also has a light shielding property as a part of the resin member 10, a part of the light L1 that passes through the light incident slit 6a enters the light detecting element 4 as stray light. This can be suppressed more reliably, and the detection accuracy can be further improved.

Further, as shown in FIG. 4, (a), in the order referred to (b), for example, the amount of the resin material may be suppressed protrusions 15a. FIG. 4C is a reference example in which a part of the light incident slit 6a is positioned between adjacent protrusions 15a and 15a when viewed from the incident direction of the light L1. Further, the protruding portion 15b located on the opposite side of the light detection slit 6a with respect to the light detection element 4 is one along the outer edge of the light detection element 4 (here, the short side 4a opposite to the light incidence slit 6a). It may be a continuation.

Further, an optical resin material for refractive index matching may be filled as an underfill resin between the light detection part 40 of the light detection element 4 and the front surface 2a of the main body part 2. Further, the light transmitting member 2 ₃ and the diffraction layer 14 may be integrally formed by a light transmitting low melting glass for replica molding. The material and shape of each component of the spectroscopic module 1 are not limited to the materials and shapes described above, and various materials and shapes can be applied.

  DESCRIPTION OF SYMBOLS 1 ... Spectroscopic module, 2 ... Main-body part, 2a ... Front surface (predetermined surface), 3 ... Spectroscopic part, 4 ... Photodetection element, 4a ... Short side (outer edge), 4b ... Long side (outer edge), 4c ... Corner part 6, light shielding layer, 6a ... light incident slit (first light passage hole), 6b ... light passage opening (second light passage hole), 10 ... resin member, 15a, 15b ... projection, 16 ... connection portion .

Claims (4)

A main body that transmits light;
A spectroscopic unit that splits light incident on the main body from a predetermined surface of the main body and reflects the light to the predetermined surface;
A light detection element that is disposed on the predetermined surface and detects the light that is split and reflected by the spectroscopic unit;
A light blocking member provided on the predetermined surface and having a first light passage hole through which light traveling to the spectroscopic section passes, and a second light passage hole through which light traveling from the spectroscopic section to the light detection element passes. Layers,
A light-shielding resin member for fixing the photodetecting element to the predetermined surface,
The resin member has a plurality of protrusions protruding from the outer edge of the light detection element when viewed from the incident direction of light,
The entirety of the first light passage hole is located between the adjacent protrusions on the outer side of the outer edge of the light detection element when viewed from the incident direction of light ,
The light detection element is formed in a substantially rectangular shape when viewed from the incident direction of light,
The adjacent protrusions are positioned at adjacent corners via short sides in the light detection element,
The spectroscopic module , wherein a length of a light detection portion of the light detection element is larger than a length of the first light passage hole in a direction parallel to the short side .   The spectroscopic module according to claim 1, wherein the first light passage hole is a light incident slit extending in a direction in which the adjacent protrusions are arranged.   3. The spectroscopic module according to claim 1, wherein the resin member further includes a connection portion that connects the protruding portions along and adjacent to the outer edge of the light detection element. Each of the protruding portions fit Ri neighboring claims, characterized in that projecting from each of the corners adjacent along a line extending at an angle of 90 ° or more 135 ° or less with respect to the short side Item 4. The spectral module according to any one of Items 1 to 3.

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