Light detection device

Abstract

To provide a photodetector capable of improving the detection accuracy of light.SOLUTION: The light detection device 1 includes a bottom wall portion 2, a sidewall portion 3 that is disposed on the bottom wall portion 2 and defines an opening portion 3c that opens on a side opposite to the bottom wall portion 2, a light detection portion 4 that is disposed on the bottom wall portion 2 and has a plurality of light detection regions 41, and a window structure portion 5 that covers the opening portion 3c. The light detection device includes a plurality of optical members 8 disposed on the first frame portion 6 so as to respectively cover the plurality of first openings 6f, and a second frame portion 7 having a plurality of second openings 7f disposed on a side opposite to the bottom wall portion 2 with respect to the first frame portion 6 in the Z direction and overlapping the plurality of light detection regions 41 when viewed from the Z direction, wherein the plurality of optical members 8 are respectively surrounded by inner surfaces of the plurality of second openings 7f.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a light detection device. [Background technology]

[0002] Patent Document 1 describes an imaging device that includes an imaging element substrate on which a plurality of light receiving elements are provided and a transparent substrate disposed opposite the imaging element substrate. In this imaging device, an optical functional structure such as a polarizing filter is formed on a part of the surface of the transparent substrate that faces the imaging element substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-15444 Summary of the Invention [Problem to be solved by the invention]

[0004] The imaging device described above may be required to have improved light detection accuracy. Therefore, an object of the present invention is to provide a light detection device that can improve light detection accuracy. [Means for solving the problem]

[0005] The photodetector of the present invention is [1] "a photodetector comprising: a bottom wall portion; a side wall portion disposed on the bottom wall portion and defining an opening that opens on the opposite side from the bottom wall portion; a photodetector portion disposed on the bottom wall portion and having a plurality of photodetection regions; and a window structure portion covering the opening, wherein the window structure portion comprises: a first frame portion having a plurality of first openings that overlap with the plurality of photodetection regions when viewed from a direction intersecting with the bottom wall portion; a plurality of optical members that are optically transparent and disposed on the first frame portion so as to cover the plurality of first openings; and a second frame portion disposed on the opposite side of the bottom wall portion from the first frame portion in the direction intersecting with the bottom wall portion and having a plurality of second openings that overlap with the plurality of photodetection regions when viewed from the direction intersecting with the bottom wall portion, wherein the plurality of optical members are each surrounded by the inner surfaces of the plurality of second openings."

[0006] In this photodetector, each optical element is surrounded by the inner surface of the second opening of the second frame. This allows the inner surface of the second opening to block light that would otherwise be incident on the optical elements from the side, thereby reducing variations in the light incidence characteristics of each optical element. Furthermore, the inner surface of the second opening can block light that exits the side of an optical element, thereby reducing crosstalk. For example, light emitted from one optical element can be prevented from entering another adjacent optical element. Furthermore, in this photodetector, the window structure includes a first frame and a second frame. This allows the portion of the first frame located between the first openings to function as a light-blocking wall, thereby reducing crosstalk. For example, light emitted from one optical element can be prevented from entering a light detection region other than the light detection region corresponding to that optical element. As described above, this photodetector can reduce variations in light incidence characteristics and crosstalk, thereby improving light detection accuracy.

[0007] The photodetector of the present invention may be [2] "the photodetector according to [1], wherein in each of the plurality of second openings, the optical member is entirely surrounded by the inner surface of the second opening." In this case, it is possible to further suppress variations in light incidence characteristics and the occurrence of crosstalk.

[0008] The photodetector of the present invention may be [3] "the photodetector according to [1] or [2], wherein the plurality of optical members are configured by a plurality of filters having different light transmission characteristics." In this case, light transmitted through the plurality of filters having different light transmission characteristics can be detected.

[0009] The photodetector of the present invention may be [4] "the photodetector according to any one of [1] to [3], wherein the photodetector section is composed of a plurality of semiconductor photodetector elements separated from one another, each having the photodetection region." In this case, the degree of freedom in arranging the plurality of photodetection regions can be increased compared to, for example, when the photodetector section is composed of a single semiconductor photodetector element on which a plurality of photodetection regions are formed. Also, costs can be reduced.

[0010] The photodetector of the present invention may be [5] "the photodetector according to any one of [1] to [4], wherein the second frame is formed separately from the first frame and is disposed with a gap between it and the first frame in a direction intersecting the bottom wall." In this case, costs can be reduced compared to when the first and second frame are formed as a single member in advance. Furthermore, for example, when the second frame is disposed on the opposite side of the bottom wall with respect to the first frame and then the optical element is disposed on the first frame, the second opening formed in the second frame facilitates positioning of the optical element. On the other hand, when the optical element is disposed on the first frame before the second frame is disposed, the optical element can be easily fixed to the first opening.

[0011] The photodetector of the present invention may be [6] "the photodetector according to any one of [1] to [5], wherein the sidewall has a step formed on the side of the photodetector, and the first frame is disposed on the step." In this case, the first frame can be positioned by being disposed on the step, and the first frame can be easily positioned.

[0012] The photodetector of the present invention may be [7] "the photodetector according to [6], wherein an electrode pad is formed on the step portion, and the electrode pad is electrically connected to the photodetector via a wire, and the first frame portion is formed with a recess, an opening, or a notch for avoiding interference with the wire." In this case, the first frame portion can be positioned by the step portion on which the electrode pad is formed, while preventing the wire from interfering with the first frame portion.

[0013] The photodetector of the present invention may be the photodetector according to [8] "in which the first frame includes a frame-shaped first member and a frame-shaped second member bonded to the first member and positioned on the bottom wall side of the first member, and the recess, the opening, or the notch is formed in the second member." In this case, for example, it is easier to suppress the generation of stray light compared to when the first frame is formed as a single member in advance.

[0014] The photodetector of the present invention may be [9] "a photodetector according to any one of [1] to [8], wherein the window structure has a vent that connects an internal space defined by the bottom wall, the side wall, and the window structure to an external space, and the vent is located outside the plurality of photodetection regions when viewed from a direction intersecting the bottom wall." In this case, the formation of the vent can prevent damage caused by air expansion in the internal space. Also, it can prevent noise caused by stray light entering through the vent and entering the photodetection region.

[0015] The photodetector of the present invention may be

[10] "the photodetector according to [9], wherein the side wall has a step formed on the side of the photodetector, and the ventilation part overlaps with the step when viewed from a direction intersecting with the bottom wall." In this case, it is possible to further suppress the generation of noise caused by stray light entering through the ventilation part and entering the photodetection region.

[0016] The photodetector of the present invention may be the photodetector according to

[10] ,

[11] "wherein the side wall portion has a pair of first wall portions facing each other and a pair of second wall portions facing each other in a direction perpendicular to the direction in which the pair of first wall portions face each other, the step portion is formed on the pair of first wall portions on the side of the photodetector, and the ventilation portion is connected to a first space formed between the step portion and the first frame portion and is connected via the first space to a second space formed between the pair of second wall portions and the photodetector." In this case, it is possible to further suppress the generation of noise caused by stray light entering through the ventilation portion and entering the photodetection region. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a light detection device that can improve the light detection accuracy. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view of a light detection device according to an embodiment. [Figure 2] 2(a) is a perspective view showing a state in which a first frame, a second frame, and optical members have been removed from the photodetector of Fig. 1. FIG. 2(b) is a perspective view showing a state in which the second frame and optical members have been removed from the photodetector of Fig. 1. [Figure 3] 2(a) is a perspective view of the first frame as viewed from the bottom wall side, and FIG. 2(b) is a perspective view showing the first frame from FIG. 2(b) with the first member removed. [Figure 4] FIG. 2 is a perspective view showing a state in which optical members are removed from the photodetector of FIG. [Figure 5]FIG. 2 is a cross-sectional perspective view taken along line VV in FIG. [Figure 6] FIG. 2 is a cross-sectional perspective view taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. [Figure 10] 2(a) to 2(c) are diagrams illustrating ventilation paths in the photodetector of FIG. 1. [Figure 11] 2(a) and 2(b) are cross-sectional views illustrating ventilation paths in the light detection device of FIG. 1. [Figure 12] 10(a) and 10(b) are enlarged plan views of a part of a photodetector according to a first modified example. [Figure 13] FIG. 10 is a plan view of a photodetector according to a second modified example. [Figure 14] 10(a) to 10(c) are diagrams illustrating ventilation paths in a photodetector according to a second modified example. [Figure 15] FIG. 10 is a cross-sectional view illustrating a ventilation path in a photodetector according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted. [Embodiment]

[0020] As shown in FIGS. 1 to 9, the photodetector 1 includes a bottom wall 2, a side wall 3, a photodetector 4, and a window structure 5. The bottom wall 2, the side wall 3, and the window structure 5 form a package for accommodating the photodetector 4. The photodetector 1 is a surface-mount package that can be directly mounted on the surface of a substrate. For example, terminals for mounting are formed on the back surface of the photodetector 1, and the photodetector 1 is directly mounted on the substrate via these terminals. The photodetector 1 has, for example, a flat, approximately rectangular parallelepiped outer shape.

[0021] As shown in FIGS. 2 and 7, the bottom wall 2 is formed into a rectangular plate shape using, for example, ceramics, and has a flat main surface 2a. Hereinafter, the direction perpendicular to the main surface 2a (thickness direction of the bottom wall 2) will be referred to as the Z direction. The direction perpendicular to the Z direction will be referred to as the X direction, and the direction perpendicular to the X and Z directions will be referred to as the Y direction. When viewed from the Z direction, the bottom wall 2 has a pair of sides along the X direction and a pair of sides along the Y direction. In addition, the side of the bottom wall 2 that faces the window structure 5 (the optical member 8 described later) in the Z direction (the lower side in FIGS. 2 and 7) will be referred to as the lower side, and the side opposite the lower side will be referred to as the upper side. These directions do not limit the manner in which the photodetector 1 is used; the photodetector 1 may be used with the bottom wall 2 facing either up or down in the vertical direction.

[0022] The side wall 3 is disposed on the principal surface 2a of the bottom wall 2. In this example, the side wall 3 is formed integrally with the bottom wall 2 (to constitute a single member) and protrudes from the principal surface 2a in the Z direction. That is, the side wall 3 constitutes a support together with the bottom wall 2. In FIG. 7, the boundary between the side wall 3 and the bottom wall 2 is indicated by a two-dot chain line (the same applies to FIGS. 8, 9, and 11). The side wall 3 is formed, for example, in a rectangular ring shape surrounding the light detection unit 4 when viewed from the Z direction, and is disposed along the outer edge of the bottom wall 2. The side wall 3 defines an opening 3c that opens to the upper side (the side opposite the bottom wall 2). The opening 3c is formed, for example, in a rectangular shape when viewed from the Z direction. The side wall 3 has a top surface 3a and an inner surface 3b that is the surface on the side (inside) of the light detection unit 4.

[0023] The side wall portion 3 has a pair of first wall portions 31 and a pair of second wall portions 32. The pair of first wall portions 31 face each other in the X direction. In FIG. 7, the boundary between the first wall portion 31 and the second wall portion 32 is indicated by a two-dot chain line (similarly in FIGS. 9 and 11). The first wall portion 31 has an outer portion 33 located on the opposite side (outside) of the light detection unit 4 and an inner portion 34 located inside the outer portion 33. A step portion 35 is formed in the first wall portion 31 because the top surface 34a of the inner portion 34 is located lower than the top surface 33a of the outer portion 33 (the height of the inner portion 34 is lower than the height of the outer portion 33). The step portion 35 is formed by the inner surface 33b of the outer portion 33 and the top surface 34a of the inner portion 34. The step portion 35 can also be considered to be formed on the top surface of the first wall portion 31. In this way, the step portion 35 is formed on the inner side (the side of the light detection unit 4) of the first wall portion 31. The step portion 35 extends along the Y direction. The pair of second wall portions 32 face each other in the Y direction (a direction perpendicular to the direction in which the pair of first wall portions 31 face each other). The second wall portion 32 has a top surface 32a and an inner surface 32b.

[0024] The photodetector 4 is disposed on the main surface 2a of the bottom wall 2. The photodetector 4 is disposed inside the side wall 3 when viewed from the Z direction. The entire photodetector 4 is formed, for example, in the shape of a rectangular plate. The photodetector 4 has multiple (four in this example) photodetection regions 41 and dummy regions 42 (dummy channels). In this example, the photodetector 4 is configured by a single (monolithic) semiconductor detection element in which multiple photodetection regions 41 are formed. The photodetector 4 is formed, for example, from silicon (Si). The photodetection region 41 is configured, for example, by a photodiode (photodetection element) and detects light L incident through the window structure 5. The photodetector 4 in this example is a photodiode array in which multiple photodetection regions 41 are arranged. Each photodetection region 41 is formed, for example, in the shape of a rectangle when viewed from the Z direction. In this example, the four photodetection regions 41 are arranged in a grid (matrix) when viewed from the Z direction, with two of each arranged along the X and Y directions.

[0025] The dummy regions 42 are formed, for example, in a cross shape so as to separate (separate) the multiple photodetection regions 41. In other words, the multiple photodetection regions 41 are arranged in multiple (four in this example) regions separated by the dummy regions 42. The dummy regions 42 are connected to a reference potential (ground) by, for example, a wire 38 described below and are grounded. The dummy regions 42 are pn junctions formed in the semiconductor substrate and are provided as dummy channels for reducing charge crosstalk (electrical crosstalk) between adjacent photodetection regions 41.

[0026] A plurality of electrode pads 36 (ten in this example) are formed on the step portions 35 of the pair of first wall portions 31. Specifically, five electrode pads are formed on each step portion 35. The five electrode pads 36 are formed, for example, on the top surface 34a (bottom surface of the step portion 35) of the inner portion 34 of the first wall portion 31. The five electrode pads 36 are formed, for example, lined up along the Y direction. Of the five electrode pads 36 on one step portion 35, two electrode pads 36 located at both ends in the Y direction are electrically connected via wires 37 to two photodetection regions 41 of the photodetector 4 adjacent to the two electrode pads 36. Of the five electrode pads 36 on the other step portion 35, two electrode pads 36 located at both ends in the Y direction are electrically connected via wires 37 to the remaining two photodetection regions 41 of the photodetector 4 adjacent to the two electrode pads 36. Of the five electrode pads formed on each step portion 35, the central electrode pad 36 is electrically connected to the dummy region 42 of the light detection unit 4 via a wire 38. Note that the wires 37 and 38 are shown only in FIG. 2(a) and are omitted in the other drawings.

[0027] 5 and 7, the window structure 5 covers (blocks) the entire opening 3c of the side wall 3 and faces the light detection unit 4 in the Z direction. The window structure 5 has a first frame 6, a second frame 7, and a plurality of optical members 8 (four in this example).

[0028] As shown in FIGS. 2(b) and 7, the first frame portion 6 is formed, for example, in the shape of a rectangular frame. The first frame portion 6 constitutes the lower portion of the window structure 5. The first frame portion 6 has a lower surface 6a, an upper surface 6b, and an outer surface 6c. The first frame portion 6 is disposed on the step portion 35 (the top surface 34a of the inner portion 34) of the first wall portion 31. More specifically, the lower surface 6a at the outer periphery of the first frame portion 6 contacts the top surface 34a of the inner portion 34 of the pair of first wall portions 31. The first frame portion 6 is located inside the opening 3c of the side wall portion 3 and is surrounded by the inner surface of the opening 3c when viewed from the Z direction. The upper surface 6b of the first frame portion 6 is located slightly lower than the top surface 33a of the outer portion 33 in the Z direction. Each of the four corners of the first frame portion 6 is chamfered (C-chamfered). The first frame portion 6 is made of, for example, a metal material (for example, stainless steel).

[0029] The first frame portion 6 has a frame portion 6d and a partition portion 6e. The frame portion 6d is formed in a rectangular frame shape. The partition portion 6e is formed in a cross shape so as to divide the inside of the frame portion 6d into multiple regions (four in this example). The partition portion 6e is disposed in a position overlapping with the dummy region 42 when viewed from the Z direction, for example.

[0030] A plurality of (four in this example) first openings 6f are formed inside the frame portion 6d, separated by partition portions 6e. That is, the first frame portion 6 has a plurality of first openings 6f. Each of the first openings 6f is formed, for example, in a rectangular shape. The plurality of first openings 6f are respectively formed at positions that overlap with the plurality of photodetection regions 41 when viewed from the Z direction. That is, the plurality of first openings 6f are respectively formed at positions corresponding to the plurality of photodetection regions 41 so that light L that has passed through the first openings 6f can enter the photodetection regions 41.

[0031] As shown in FIGS. 2(b), 3(a), and 3(b), the first frame 6 includes a first member 61 and a second member 62 located below the first member 61. The first member 61 is formed, for example, in the shape of a rectangular frame. The first member 61 has a frame portion 61a and a partition portion 61b. The frame portion 61a is formed, for example, in the shape of a rectangular frame. The frame portion 61a constitutes a portion of the upper side of the frame portion 6d of the first frame 6. The partition portion 61b is formed in a cross shape so as to divide the inside of the frame portion 61a into four sections. The partition portion 61b constitutes a portion of the upper side of the partition portion 6e of the first frame 6. Four openings 61c separated by the partition portions 61b are formed inside the frame portion 61a. The openings 61c constitute a portion of the upper side of the first opening 6f of the first frame 6.

[0032] The second member 62 is located below the first member 61 (FIG. 7). In this example, the second member 62 is formed separately from the first member 61 and is bonded to the first member 61 with, for example, an adhesive.

[0033] The second member 62 is formed, for example, in the shape of a rectangular frame. The second member 62 has a frame portion 62a and partition portions 62b. The frame portion 62a is formed, for example, in the shape of a rectangular frame. The frame portion 62a constitutes a portion of the lower side of the frame portion 6d of the first frame portion 6. The partition portions 62b are formed in a cross shape so as to divide the inside of the frame portion 62a into four sections. The partition portions 62b constitute a portion of the lower side of the partition portion 6e of the first frame portion 6. A plurality of openings 62c (four in this example) are formed inside the frame portion 62a, separated by the partition portions 62b. The multiple openings 62c are formed to be slightly larger than the opening 61c of the first member 61 when viewed from the Z direction. The openings 62c constitute a portion of the lower side of the first opening 6f of the first frame portion 6.

[0034] A plurality of openings 62d (six in this example) are formed in the frame portion 62a of the second member 62. The plurality of openings 62d include four openings 62e and two openings 62f. The four openings 62e are formed at four corners of the frame portion 62a of the second member 62 and are connected to the corners of the four openings 62c, respectively. The four openings 62e are formed at positions overlapping with the four wires 37 described above when viewed from the Z direction. When viewed from the Z direction, each opening 62e is formed in an oval shape extending, for example, along the X direction.

[0035] The two openings 62f are formed on a pair of sides of the frame portion 62a of the second member 62 along the Y direction, respectively, and are formed in the center of the sides in the Y direction. One of the openings 62f is formed at a position overlapping with the wire 38 when viewed from the Z direction. When viewed from the Z direction, each opening 62e is formed in an oval shape extending along the X direction, for example.

[0036] The upper sides of the multiple openings 62d are blocked by the lower surface 61g of the frame portion 61a of the first member 61. By blocking the openings 62d by the lower surface 61g in this manner, multiple (six in this example) recesses 6h are formed in the lower surface 6a of the first frame portion 6. The recesses 6h are provided to avoid interference between the first frame portion 6 (window structure portion 5) and the wires 37 and 38. In other words, by arranging the wires 37 and 38 in the recesses 6h, it is possible to prevent the wires 37 and 38 from coming into contact with the first frame portion 6.

[0037] As shown in FIGS. 4 and 7 , the second frame 7 is disposed on the opposite side of the first frame 6 from the bottom wall 2 in the Z direction. The second frame 7 has a lower surface 7a and an upper surface 7b. The second frame 7 is formed separately from the first frame 6 and disposed with a gap G between it and the first frame 6 in the Z direction. From a different perspective, the second frame 7 is disposed on the upper surface 6b of the first frame 6 via the gap G at its lower surface 7a. The second frame 7 is formed, for example, in the shape of a rectangular frame. The second frame 7 is disposed on the top surface 3a of the side wall 3 and fixed to the top surface 3a with, for example, an adhesive. Specifically, the outer periphery of the second frame 7 rests on the top surfaces 33a of the outer portions 33 of the pair of first wall portions 31 and the top surfaces 32a of the pair of second wall portions 32. Each of the four corners of the second frame 7 is chamfered (C-chamfered). The second frame 7 is formed from the same material as the first frame 6. The lower surface 7a of the second frame 7 may be bonded to the upper surface 6b of the first frame 6 with an adhesive. In other words, the second frame 7 may be disposed on the first frame 6 without any gaps.

[0038] The second frame portion 7 has a frame portion 7d and a partition portion 7e. The frame portion 7d is formed in a rectangular frame shape. The partition portion 7e is formed in a cross shape so as to divide the inside of the frame portion 7d into multiple regions (four in this example). The partition portion 7e is disposed in a position overlapping with the dummy region 42 when viewed from the Z direction, for example.

[0039] A plurality of second openings 7f (four in this example) are formed inside the frame portion 7d, separated by partition portions 7e. That is, the second frame portion 7 has a plurality of second openings 7f. Each second opening 7f is formed, for example, in a rectangular shape. The plurality of second openings 7f are formed at positions overlapping with the plurality of photodetection regions 41 when viewed from the Z direction. That is, the plurality of second openings 7f are formed at positions corresponding to the plurality of photodetection regions 41 so that light L passing through the second openings 7f can enter the photodetection regions 41. Furthermore, the plurality of second openings 7f are formed at positions overlapping with the plurality of first openings 6f when viewed from the Z direction. The four corners of each second opening 7f are recessed in a rounded shape toward the outside to avoid the corners (edges) of the optical member 8. Furthermore, a plurality of ventilation portions 9 are formed in the frame portion 7d of the second frame portion 7. Details of the ventilation portions 9 will be described later.

[0040] As shown in FIGS. 1 and 7 , the optical members 8 are arranged on the first frame 6 so as to cover the first openings 6f of the first frame 6, respectively, and face the light detection unit 4. When viewed from the Z direction, the optical members 8 are arranged on a step portion (a step portion formed by the upper surface 6b of the first frame 6 and the inner surface of the second opening 7f) formed by the second opening 7f of the second frame 7 being slightly larger than the first opening 6f of the first frame 6. The optical members 8 are formed, for example, in the shape of a rectangular plate. When viewed from the Z direction, each optical member 8 is formed slightly larger than the corresponding first opening 6f of the first frame 6. The optical members 8 have a lower surface 8a, an upper surface 8b, and an outer surface 8c. The lower surface 8a is in contact with the upper surface 6b of the first frame 6.

[0041] Each optical member 8 is disposed inside the second opening 7f of the second frame 7. The outer surface 8c of the optical member 8 faces the inner surface of the second opening 7f around the entire periphery. That is, the optical member 8 is surrounded by the inner surface of the second opening 7f. In this example, the entire optical member 8 is surrounded by the inner surface of the second opening 7f. That is, the entire optical member 8 is housed in the second opening 7f, and the optical member 8 does not protrude from the second opening 7f. The upper surface 8b of the optical member 8 is located lower (towards the bottom wall 2) than the upper surface 7b of the second frame 7 in the Z direction.

[0042] The optical members 8 are light-transmitting members such as polarizing filters. In this example, the optical members 8 are configured by a plurality of filters (window materials) having different light transmission characteristics. For example, the optical members 8 are polarizing filters that transmit light in different wavelength ranges.

[0043] As shown in FIGS. 5 to 11 (particularly FIG. 9), the photodetector 1 has an internal space S defined by a bottom wall 2, a side wall 3, and a window structure 5. The internal space S includes, for example, a pair of spaces S1 (first spaces), a pair of spaces S2, a pair of spaces S3, and a pair of spaces S4 (second spaces). The pair of spaces S1 are spaces formed between a step portion 35 in the X direction and the first frame 6, and are disposed on one side and the other in the X direction, extending along the Y direction (FIGS. 5 and 7). More specifically, the space S1 is formed between an inner surface 33b of an outer portion 33 of the side wall 3 that constitutes the step portion 35 and an outer surface 6c of the first frame 6.

[0044] The pair of spaces S2 are spaces formed between the pair of second wall portions 32 and the first frame portion 6 in the Y direction, and are arranged on one side and the other side in the Y direction, extending along the X direction (FIGS. 6 and 8). More specifically, the space S2 is formed between the inner surface 32b of the second wall portion 32 and the outer surface 6c of the first frame portion 6. The space S2 is connected to the space S1 at a position corresponding to a corner of the first frame portion 6, for example (FIG. 10(b)). That is, the spaces S1 and S2 define an annular space surrounding the first frame portion 6 when viewed from the Z direction.

[0045] The pair of spaces S3 are spaces formed between the pair of first wall portions 31 and the light detection unit 4 in the X direction, and are arranged on one side and the other side in the X direction, and extend along the Y direction (FIGS. 5 and 7). More specifically, the space S3 is formed between the inner surface 3b of the inner portion 34 of the first wall portion 31 and the outer surface of the light detection unit 4.

[0046] The pair of spaces S4 are spaces formed between the pair of second wall portions 32 and the photodetector 4 in the Y direction. They are disposed on one side and the other side in the Y direction and extend along the X direction (FIGS. 6 and 8). The space S4 is formed, for example, between the inner surface 32b of the second wall portion 32 and the outer surface of the photodetector 4. The space S4 overlaps with the space S2 when viewed from the Z direction and is connected to the space S2. As described above, the space S2 is connected to the space S1, and therefore the space S4 is also connected to the space S1 via the space S2. The space S4 is also connected to the space S3 at a position corresponding to a corner of the photodetector 4, for example. That is, the spaces S3 and S4 define an annular space surrounding the photodetector 4 when viewed from the Z direction. A gap is formed between the first frame portion 6 and the photodetector 4, and the spaces S3 and S4 are connected to the light receiving surface in the photodetection region 41 and the space inside the first opening 6f via the gap.

[0047] The frame portion 7d of the second frame portion 7 of the window structure 5 has a plurality of (four in this example) ventilation portions 9 formed therein that connect the internal space S to the external space outside the photodetector 1 ( FIG. 1 ). The ventilation portions 9 are, for example, cylindrical through-holes that penetrate the frame portion 7d in the Z direction. The ventilation portions 9 are formed, for example, at the four corners of the frame portion 7d of the second frame portion 7. When viewed from the Z direction, the ventilation portions 9 are located outside the plurality of photodetection regions 41 (photodetection units 4) and are formed in positions that overlap with the space S1. That is, when viewed from the Z direction, the ventilation portions 9 overlap with the step portion 35 (the top surface 34a of the inner portion 34). As a result, for example, the step portion 35 and the first frame portion 6 can prevent stray light that has entered through the ventilation portions 9 from entering the photodetection region 41.

[0048] 10(a) to (c) and 11(a) and (b) are diagrams for explaining ventilation paths in the internal space S. FIG. 10(a) is a plan view showing an enlarged corner of the light-detecting device 1. FIG. 10(b) is a perspective view showing an enlarged corner of the light-detecting device 1. The second frame 7 and the optical member 8 are omitted from FIG. 10(b). FIG. 10(c) is a perspective view showing an enlarged corner of the light-detecting device 1 with the second frame 7 and the optical member 8 attached. FIG. 11(a) is a partial enlarged view of the cross-sectional view of FIG. 8. FIG. 11(b) is a partial enlarged view of the cross-sectional view of FIG. 9.

[0049] As shown in FIGS. 10(a) to 10(c), air present in the internal space S can move, for example, through space S4 to space S2 (arrow M1 in the figure), from space S2 to space S1 (arrow M2 in the figure), and from space S1 through the ventilation section 9 to the external space (arrow M3 in the figure). More specifically, as shown in FIG. 11(a), space S4 is connected to space S2, so air in space S4 can move to space S2 (arrow M1 in the figure). Furthermore, as shown in FIG. 11(b), space S1 and the ventilation section 9 are connected, so air that has moved to space S1 through space S2 can move to the external space through the ventilation section 9. In this way, the ventilation section 9 is connected to space S1 and is also connected to space S4 via space S1.

[0050] Therefore, even if the air in the internal space S expands, the expanded air can be released to the external space via the ventilation section 9. This makes it possible to prevent damage to the internal space S due to the expansion of the air. In other words, if the ventilation section 9 is not formed, for example, the pressure in the internal space S may increase due to the expansion of the air due to the influence of heat during the manufacturing process of the photodetector 1 (for example, during the reflow process in surface mounting), which may damage the package including the bottom wall 2, the side wall 3, and the window structure 5. On the other hand, in this embodiment, the ventilation section 9 allows the air in the internal space S to escape to the external space, so that the increase in pressure in the internal space S can be prevented. This makes it possible to prevent damage to the internal space S due to the expansion of the air.

[0051] When the above-described photodetector 1 is in use, light L is incident on the upper surface 8b of the optical member 8. The light L passes through the optical member 8, exits from the lower surface 8a of the optical member 8, and enters the corresponding photodetection region 41 of the photodetector 4. The photodetector 1 detects the light L incident on each photodetection region 41. [Action and effect]

[0052] In the photodetector 1, each optical member 8 is surrounded by the inner surface of the second opening 7f of the second frame 7. This allows the inner surface of the second opening 7f to block light L that would otherwise be incident on the optical members 8 from the side, thereby reducing variations in the light incidence characteristics of each optical member 8. Furthermore, the inner surface of the second opening 7f can block light emitted from the outer surface 8c of each optical member 8, thereby reducing the occurrence of crosstalk. For example, this prevents light emitted from one optical member 8 from entering another adjacent optical member 8. Furthermore, in the photodetector 1, the window structure 5 has a first frame 6 and a second frame 7. This allows the portion of the first frame 6 between the first openings 6f (the partition portion 6e) to function as a light-blocking wall, thereby reducing the occurrence of crosstalk. For example, this prevents light emitted from one optical member 8 from entering a photodetection region 41 other than the photodetection region 41 corresponding to that optical member 8. As described above, the photodetector 1 can suppress variations in light incidence characteristics and the occurrence of crosstalk, thereby improving the light detection accuracy.

[0053] In the photodetector 1, the entire optical member 8 is surrounded by the inner surface of the second opening 7f. In other words, the entire optical member 8 is housed in the second opening 7f. This makes it possible to further suppress variations in light incidence characteristics and the occurrence of crosstalk.

[0054] The optical members 8 are configured by a plurality of filters having different light transmission characteristics, thereby making it possible to detect light that has passed through a plurality of filters having different light transmission characteristics.

[0055] The second frame portion 7 is formed separately from the first frame portion 6 and is disposed with a gap G between it and the first frame portion 6 in the Z direction (the direction intersecting the bottom wall portion 2). This reduces the cost of the window structure 5 compared to, for example, when the first frame portion 6 and the second frame portion 7 are formed as a single member in advance. Furthermore, for example, when the optical member 8 is disposed on the first frame portion 6 after the second frame portion 7 is disposed on the opposite side of the bottom wall portion 2 with respect to the first frame portion 6, the second opening 7f formed in the second frame portion 7 makes it easy to position the optical member 8. On the other hand, when the optical member 8 is disposed on the first frame portion 6 before the second frame portion 7 is disposed, it is easy to fix the optical member 8 to the first opening 6f of the first frame portion 6.

[0056] The first frame portion 6 is disposed on the step portion 35. This allows the first frame portion 6 to be positioned by disposing it on the step portion 35, and the first frame portion 6 can be easily positioned.

[0057] The first frame portion 6 is formed with recesses 6h for avoiding interference with the wires 37, 38. This prevents the wires 37, 38 from interfering with the first frame portion 6, and allows the first frame portion 6 to be positioned by the step portions 35 on which the electrode pads 36 are formed.

[0058] The first frame 6 includes a frame-shaped first member 61 and a frame-shaped second member 62 that is bonded to the first member 61 and is positioned below the first member 61, and the recess 6h is formed in the second member 62. This makes it easier to suppress the generation of stray light compared to, for example, when the first frame 6 is formed as a single member in advance. This will be further explained below with reference to Figures 12(a) and (b).

[0059] 12(a) and 12(b) are enlarged plan views of a corner of a photodetector 100 according to a first modification. In the photodetector 100 according to the first modification, the first frame 106 does not include a first member and is formed only by the second member. In this case, the opening 162d formed in the second member to avoid interference with the wires is not blocked by the first frame. Therefore, as shown in FIG. 12(a), a portion of the bottom wall 2 may be exposed through the opening 162d of the second member when viewed from the Z direction, and may also be exposed through a gap between the second opening 107f of the second frame 107 and the optical member 108. Furthermore, as shown in FIG. 12(b), a portion of the photodetector 4 may be exposed through the opening 162d of the second member when viewed from the Z direction, and may also be exposed through a gap between the second opening 107f of the second frame 107 and the optical member 108. As described above, in the photodetector 100 according to the first modification, the bottom wall 2 and a portion of the photodetector 4 are exposed through the opening 162d, which may allow stray light to enter the device through the opening 162d. To prevent this stray light from entering, it is possible to reduce the size of the opening in the first frame 106 at the portion that overlaps with the photodetection region of the photodetector, or to increase the size of the optical member 108 so that the bottom wall 2 and a portion of the photodetector 4 are not exposed. However, reducing the size of the opening in the first frame 106 may reduce the amount of light incident on the photodetector 4, potentially resulting in a decrease in output from the photodetector 4. Furthermore, increasing the size of the optical member 108 may increase costs.

[0060] On the other hand, in the photodetector 1 according to the embodiment, the first member 61 closes the opening 62d of the second member 62. That is, the opening 62d of the second member 62 is closed by the first member 61, thereby forming a recess 6h in the second member 62 (first frame 6). This prevents a portion of the bottom wall 2 or the photodetector 4 from being exposed through the opening 62d when viewed from the Z direction, thereby suppressing the generation of stray light. Furthermore, compared to, for example, increasing the size of the optical member 8, forming the first frame 6 into a two-layer structure including the first member 61 and the second member 62 reduces costs. Therefore, compared to, for example, increasing the size of the optical member 8, the generation of stray light can be more easily suppressed.

[0061] The window structure 5 is formed with a ventilation section 9 that connects the internal space S defined by the bottom wall 2, the side wall 3, and the window structure 5 to the external space, and the ventilation section 9 is located outside the multiple light detection areas 41 when viewed from the Z direction. By forming the ventilation section 9 in this manner, it is possible to suppress damage caused by air expansion in the internal space S. Furthermore, by positioning the ventilation section 9 outside the multiple light detection areas 41, it is possible to suppress the generation of noise caused by stray light entering through the ventilation section 9 entering the light detection areas 41.

[0062] When viewed from the Z direction, the ventilation portion 9 overlaps with the step portion 35. This makes it possible to further suppress the generation of noise caused by stray light entering through the ventilation portion 9 and entering the light detection region 41.

[0063] The ventilation section 9 is connected to a space S1 (first space) formed between the step section 35 and the first frame section 6, and is also connected via the space S1 to a space S4 (second space) formed between the pair of second wall sections 32 and the light detection section 4. This makes it possible to further suppress the generation of noise caused by stray light entering through the ventilation section 9 and entering the light detection region 41. [Variations]

[0064] A light-detecting device 1A according to a second modified example will be described with reference to Figures 13 to 15. The light-detecting device 1A shown in Figure 13 differs from the light-detecting device 1 according to the embodiment in that the ventilation portion 9A is formed by a relief portion 7h rather than a through-hole, and that the first frame portion 6A does not have a first member 61 but is formed only by a second member 62A. In Figure 15, the boundaries between the side wall portion 3 and the bottom wall portion 2 and the boundaries between the first wall portion 31 and the second wall portion 32 are indicated by two-dot chain lines.

[0065] The ventilation portion 9A according to the second modification is formed by enlarging the recess 7h formed at the corner of the second opening 7f of the second frame portion 7A compared to the embodiment. The recess 7h is, for example, a U-shaped notch recessed toward the outside of the second opening 7f at the corner of the second opening 7f. From a different perspective, the recess 7h is an opening defined by the notch. In this example, the ventilation portion 9A is a space formed between the inner surface of the recess 7h and the outer surface 8c of the optical member 8.

[0066] The first frame 6A according to the second modification has openings 62e at the four corners of the first frame 6A that have a different shape than the first frame 6 of the embodiment. In the openings 62e according to the second modification, for example, part of the inner surface of the opening 62c is recessed (cut out) outward in a generally U-shape.

[0067] 14(a) to 14(c) and 15 are diagrams illustrating ventilation paths in the internal space S in a modified light-detecting device 1A. FIG. 14(a) is a plan view showing an enlarged corner of the light-detecting device 1A. FIG. 14(b) is a perspective view showing an enlarged corner of the light-detecting device 1A. The second frame 7 and the optical member 8 are omitted from FIG. 14(b). FIG. 14(c) is a perspective view showing an enlarged corner of the light-detecting device 1A with the second frame 7 and the optical member 8 attached. FIG. 15 is an enlarged cross-sectional view taken along a diagonal line of the light-detecting device 1A.

[0068] 14(a) to 14(c) and 15, the air in the internal space S in the modified example can move, for example, through space S4 to space S2 (arrow M1 in the figure), from space S2 to space S1 (arrow M2 in the figure), and from space S1 to the external space through the ventilation section 9A (arrow M3 in the figure), similar to the embodiment. Therefore, similar to the embodiment, the air in the internal space S can be released to the external space through the ventilation section 9A, and damage due to expansion of the internal space S can be suppressed.

[0069] The photodetector 1A according to the above-described modified example can also suppress variations in light incidence characteristics and the occurrence of crosstalk, as can the photodetector 1 according to the above-described embodiment, and can improve the light detection accuracy.

[0070] The present invention is not limited to the above-described embodiment and modified examples. For example, the materials and shapes of the components are not limited to those described above, and various materials and shapes can be adopted.

[0071] The photodetector 4 may be configured with a plurality of semiconductor photodetector elements (e.g., discrete semiconductor elements) that are separated from one another and each have a photodetection region 41. This allows for greater flexibility in arranging the plurality of photodetection regions 41 compared to, for example, the photodetector device 1 according to the embodiment, where the photodetector 4 is configured with a single semiconductor detector element on which a plurality of photodetection regions 41 are formed. This also allows for cost reduction. One photodetection region 41 may be configured with a plurality of photodiodes. In this case, the first opening 6f of the first frame 6 may overlap with a plurality of photodiodes when viewed from the Z direction. From a different perspective, the first opening 6f may overlap with a plurality of photodetection regions 41 when viewed from the Z direction. The same applies to the second opening 7f of the second frame 7 and the optical member 8.

[0072] The number of first openings 6f does not have to be four, and may be two or more (for example, five). In this case, for example, four first openings 6f may be arranged to surround one first opening 6f. The first openings 6f do not have to be rectangular, and may have any shape such as a polygon, a rhombus, or a circle. The multiple first openings 6f do not have to have the same shape, and at least one opening may have a shape different from the others.

[0073] The optical member 8 does not have to be entirely surrounded by the inner surface of the second opening, and a portion of the optical member 8 may protrude from the second opening 7f in the Z direction. That is, the upper surface 8b of the optical member 8 may be located higher than the upper surface 7b of the second frame portion 7. Furthermore, the optical members 8 do not have to be made up of multiple filters having different light transmission characteristics, and may be made up of multiple filters having the same light transmission characteristics. The optical member 8 does not have to be made up of a filter, and may be made up of a window member (e.g., a glass plate) that does not have a filtering function.

[0074] The electrode pad 36 does not have to be formed on the step portion 35, and may be formed, for example, on the main surface 2a of the bottom wall portion 2. The first wall portion 31 does not have to have the step portion 35, and for example, the first wall portion 31 may have only the outer portion 33 without the inner portion 34. The first frame portion 6 does not have to have a recess, opening, or notch to avoid interference with the wires 37 and 38. The first frame portion 6 does not have to include the first member 61 and the second member 62, and may be formed in advance as a single member.

[0075] The ventilation portion 9 does not have to overlap with the step portion 35 when viewed from the Z direction. For example, it may be formed outside the light detection area at a position that does not overlap with the step portion 35. The ventilation portion 9 may connect the internal space S to the external space via a ventilation path other than the above. The ventilation portion 9 does not have to be formed in the window structure 5. The side wall portion 3 does not have to be formed integrally with the bottom wall portion 2, but may be formed separately from the bottom wall portion 2 and disposed on the bottom wall portion 2. Alternatively, the side wall portion 3 may be formed integrally with the window structure 5 (e.g., the first frame portion 6). The second frame portion 7 does not have to be formed separately from the first frame portion 6, but the first frame portion 6 and the second frame portion 7 may be formed in advance as a single member. Furthermore, the second frame portion 7 does not have to be disposed with a gap between it and the first frame portion 6 in the Z direction, and the lower surface 7a may be in contact with the upper surface 6b of the first frame portion 6.

[0076] The first opening 6f and the second opening 7f only need to overlap with the light detection region 41 when viewed from a direction intersecting the bottom wall 2, and this direction does not necessarily have to be a direction (Z direction) perpendicular to the bottom wall 2. In other words, it is only necessary that the light L that has passed through the first opening 6f and the second opening 7f can be incident on the light detection region 41. [Explanation of symbols]

[0077] 1, 1A...photodetector, 2...bottom wall portion, 3...side wall portion, 3c...opening, 4...photodetector portion, 5...window structure portion, 6...first frame portion, 6f...first opening, 6h...recess, 7, 7A...second frame portion, 7f...second opening, 8...optical member, 9, 9A...ventilation portion, 32...second wall portion, 35...step portion, 36...electrode pad, 37, 38...wire, 41...photodetector region, 61...first member, 62, 62A...second member, S...internal space, S1...space (first space), S4...space (second space).

Claims

1. A bottom wall portion; a side wall portion disposed on the bottom wall portion and defining an opening on a side opposite the bottom wall portion; a light detection unit disposed on the bottom wall and having a plurality of light detection regions; a window structure covering the opening, The window structure includes: a first frame portion having a plurality of first openings that overlap with the plurality of light detection regions when viewed from a direction intersecting the bottom wall portion; a plurality of optical members that are optically transparent and that are arranged on the first frame portion so as to cover the plurality of first openings, respectively; a second frame portion that is disposed on the opposite side of the bottom wall portion with respect to the first frame portion in a direction intersecting the bottom wall portion, and has a plurality of second openings that respectively overlap with the plurality of light detection regions when viewed from the direction intersecting the bottom wall portion; The optical members are each surrounded by the inner surfaces of the second openings.

2. The light detection device according to claim 1 , wherein in each of the plurality of second openings, the optical member is entirely surrounded by an inner surface of the second opening.

3. 3. The photodetector according to claim 1, wherein the plurality of optical members are constituted by a plurality of filters having different light transmission characteristics.

4. 3. The photodetector according to claim 1, wherein the photodetector section is composed of a plurality of semiconductor photodetector elements separated from one another, each of which has the photodetection region.

5. 3. The photodetector according to claim 1, wherein the second frame portion is formed separately from the first frame portion and is disposed with a gap between the second frame portion and the first frame portion in a direction intersecting the bottom wall portion.

6. the sidewall portion has a step portion formed on the side of the light detection portion, The light detection device according to claim 1 , wherein the first frame portion is disposed on the step portion.

7. An electrode pad is formed on the step portion, the electrode pad is electrically connected to the light detection unit via a wire, The photodetector according to claim 6 , wherein the first frame portion has a recess, an opening, or a notch formed therein to avoid interference with the wire.

8. the first frame portion includes a frame-shaped first member and a frame-shaped second member bonded to the first member and positioned on the bottom wall portion side of the first member, The light detection device according to claim 7 , wherein the recess, the opening, or the notch is formed in the second member.

9. a ventilation section is formed in the window structure section, the ventilation section connecting an internal space defined by the bottom wall section, the side wall section, and the window structure section to an external space; The light detection device according to claim 1 , wherein the ventilation portion is located outside the plurality of light detection regions when viewed from a direction intersecting the bottom wall portion.

10. the sidewall portion has a step portion formed on the side of the light detection portion, The light detecting device according to claim 9 , wherein the ventilation portion overlaps the step portion when viewed from a direction intersecting the bottom wall portion.

11. the side wall portion has a pair of first wall portions facing each other and a pair of second wall portions facing each other in a direction perpendicular to the direction in which the pair of first wall portions face each other, the step portion is formed on the pair of first wall portions on the side of the light detection portion, 11. The light detection device according to claim 10, wherein the ventilation portion is connected to a first space formed between the step portion and the first frame portion, and is connected to a second space formed between the pair of second wall portions and the light detection portion via the first space.

Images