Light detection device

Abstract

The objective is to provide a light detection device that reduces design man-hours and manufacturing costs, and enables miniaturization of the device. [Solution] The light detection device 1 comprises a circuit board 2 and an optical device 3. The circuit board 2 has a first surface and a second surface opposite to the first surface, and is provided with a window portion 21 that penetrates the first surface and the second surface. The optical device 3 has a plurality of optical sensors 4a, 4b, and is mounted on the second surface of the circuit board 2 with the surface on which the plurality of optical sensors 4a, 4b are provided facing the second surface of the circuit board 2. The plurality of optical sensors 4a, 4b are arranged at different positions within a range in which they can receive light incident from the side of the first surface of the circuit board 2 through the window portion 21. The optical device 3 detects the direction of light based on the output values ​​of each of the plurality of optical sensors 4a, 4b.

Description

Technical Field

[0001] This disclosure relates to a light detection device.

Background Art

[0002] Patent Document 1 discloses an example in which a solar sensor for detecting the intensity of solar radiation is provided in a vehicle. The solar sensor is installed, for example, at the upper part of the instrument panel of the vehicle, can detect from which direction sunlight is irradiating the vehicle, and is used for control such as adjusting the air conditioning on either the left or right based on the detection result.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0004] [Summary] However, in a light detection device that detects the direction of light such as a solar sensor, a configuration for intentionally controlling the responsiveness of the optical sensor with respect to the incident angle of light is required. Specifically, a light detection device such as a solar sensor includes a substrate, a light transmissive body, and a light shielding body, and intentionally controls the responsiveness of the optical sensor with respect to the incident angle of light by adopting a double - mold structure in which the substrate on which the optical sensor is mounted is covered with the light transmissive body and the light shielding body. Therefore, a light detection device adopting the double - mold structure requires a package with a complex structure, and problems such as an increase in design man - hours, an increase in manufacturing cost, and an increase in component size occur.

[0005] This disclosure has been made to solve the above problems, and its object is to provide a light detection device capable of reducing design man - hours and manufacturing cost and miniaturizing the device.

[0006] A light detection device according to a certain aspect of this disclosure comprises a circuit board and an optical device. The circuit board has a first surface and a second surface opposite to the first surface, and is provided with a window that penetrates the first surface and the second surface. The optical device has a plurality of optical sensors and is mounted on the second surface of the circuit board with the surface on which the plurality of optical sensors are provided facing the second surface of the circuit board. The plurality of optical sensors are each positioned at different locations within a range in which they can receive light incident from the side of the first surface of the circuit board through the window. The optical device detects the direction of light based on the output value of each of the plurality of optical sensors.

[0007] According to this disclosure, it is possible to provide an optical detection device that can reduce design man-hours and manufacturing costs and miniaturize the device. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view of the photodetector according to Embodiment 1. [Figure 2] This is a plan view of the light detection device according to Embodiment 1. [Figure 3] This figure shows the relationship between the detection angle and the detection sensitivity ratio of the light detection device according to Embodiment 1. [Figure 4] This is a cross-sectional view of the photodetector according to Embodiment 2. [Figure 5] This is a plan view of the light detection device according to Embodiment 2. [Figure 6] This figure shows the relationship between the detection angle and the detection sensitivity ratio of the light detection device according to Embodiment 2. [Figure 7] This is a cross-sectional view of the photodetector according to Embodiment 3. [Figure 8] This is a plan view of the photodetector according to Modification 1. [Figure 9] This is a plan view of the photodetector according to Modification 2.

[0009] [Detailed explanation] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the following, the same or corresponding parts in the drawings will be denoted by the same reference numerals, and their descriptions will not be repeated in principle. While multiple embodiments will be described below, it has been intended from the outset that the configurations described in each embodiment may be combined as appropriate.

[0010] <Embodiment 1> Figure 1 is a cross-sectional view of the light detection device 1 according to Embodiment 1. Figure 2 is a plan view of the light detection device 1 according to Embodiment 1. Note that Figure 2 shows a plan view of the light detection device 1 as seen from the circuit board 2 side. Also, Figure 1 is a cross-sectional view of plane II in Figure 2. The light detection device 1 is a solar radiation sensor that is installed, for example, on the upper part of the instrument panel of a vehicle and detects the direction of sunlight in response to the received light. Note that the light detection device 1 is not limited to a solar radiation sensor, but can be any light detection device capable of detecting the direction of light, such as a motion sensor.

[0011] In the following, the structure of the photodetector 1 will be described with reference to Figures 1 and 2. In the following description, the structure of the photodetector 1 will be described with the optical device 3 facing downwards and the device laid flat, so the circuit board 2 will be on the upper side.

[0012] The photodetector 1 includes a circuit board 2 and an optical device 3. The circuit board 2 is a mounting substrate for mounting the optical device 3. The circuit board 2 is made of a printed circuit board such as a glass composite substrate, a glass epoxy substrate, or an FR-4 substrate. The circuit board 2 has an upper surface (first surface) and an opposite lower surface (second surface), and the optical device 3 is mounted on the lower surface.

[0013] The optical device 3 is a semiconductor device equipped with optical sensors 4a and 4b, and utilizes a WLCSP (Wafer Level Chip Size Package). Specifically, the optical device 3 has optical sensors 4a and 4b, composed of photodiodes and the like, formed on a semiconductor chip 31 (for example, a silicon chip). When the circuit board 2 is viewed from above, the shapes of the optical sensors 4a and 4b are, for example, rectangular or square. Furthermore, on the surface of the optical device 3 where the optical sensors 4a and 4b are provided, electrode pads 32 are formed that are electrically connected to the optical sensors 4a and 4b.

[0014] The optical device 3 is mounted on the circuit board 2 by a flip-chip connection with the side on which the electrode pads 32 are provided facing the bottom surface of the circuit board 2. Specifically, the optical device 3 is electrically connected to the wiring (not shown) provided on the bottom surface of the circuit board 2 and the electrode pads 32 by solder 33. The optical device 3 has optical sensors 4a and 4b and the electrode pads 32 on the same surface. Therefore, a window portion 21 is provided in the circuit board 2 that penetrates the top and bottom surfaces, and light is introduced to the optical sensors 4a and 4b facing the bottom surface of the circuit board 2. The optical sensors 4a and 4b are positioned at different locations within a range in which they can receive light incident from the top surface side of the circuit board 2 through the window portion 21.

[0015] As shown in Figure 2, when the circuit board 2 is viewed from above, an optical sensor 4a is positioned on one edge of the rectangular window portion 21, and an optical sensor 4b is positioned on the other edge of the window portion 21 opposite to the first edge. The light detection device 1 can detect the direction of light in one dimension with respect to the direction of the optical sensors 4a and 4b which are arranged in a row. However, in order to detect the direction of light, the light detection device 1 needs to intentionally control the responsiveness (direction angle characteristics) of the optical sensors 4a and 4b to the angle of incidence of light, but it does not employ a double mold structure including a light shield as in the conventional method. Instead of providing a light shield, the light detection device 1 positions the optical sensors 4a and 4b near the edge of the window portion 21 of the circuit board 2, as shown in Figure 1. In other words, the light detection device 1 uses the circuit board 2 as a light shield to control the direction angle characteristics of the optical sensors 4a and 4b and detect the direction of light.

[0016] When light is incident on optical sensors 4a and 4b through the window portion 21, the circuit board 2 casts a shadow depending on the angle of incidence, blocking the light illuminating optical sensors 4a and 4b. The thickness of the circuit board 2 is generally about 500um to 1mm. In contrast, the directional angle characteristics of optical sensors 4a and 4b can be changed by adjusting the distance between optical sensors 4a and 4b and the circuit board 2, and the dimensions of optical sensors 4a and 4b. In Figure 1, the distance from the surface on which optical sensors 4a and 4b are provided to the top surface of the circuit board 2 is defined as the first distance d1, the distance from the edge of the window portion 21 to the side of the optical sensor 4a and 4b closest to it when viewed from the top surface of the circuit board 2 is defined as the second distance d2, and the distance from the edge of the window portion 21 to the side of the optical sensor 4a and 4b furthest from it is defined as the third distance d3.

[0017] Specifically, the relationship between the detection angle and the detection sensitivity ratio of the light detection device 1 is determined by setting the first distance d1 to 500 μm, the second distance d2 to 100 μm, and the third distance d3 to 200 μm. Figure 3 is a diagram showing the relationship between the detection angle and the detection sensitivity ratio of the light detection device 1 according to Embodiment 1. In Figure 3, the detection angle is the angle of incidence of light with respect to the normal direction (detection angle = 0 degrees) of the optical sensors 4a and 4b. Specifically, the detection angle is the angle of incidence θ with respect to the normal direction of the optical sensor 4b shown in Figure 1, where the angle to the left is shown as a negative angle and the angle to the right is shown as a positive angle. In Figure 3, the detection sensitivity ratio is the ratio of the light ray amounts when the light ray amount when light is received from the normal direction is set to 1.0 for the optical sensors 4a and 4b.

[0018] Figure 3 shows, as an example, detection examples of optical sensors 4a and 4b. In Figure 3, the detection characteristics of optical sensor 4a are shown by a solid line, and the detection characteristics of optical sensor 4b are shown by a dashed line. As shown in Figure 3, optical sensor 4a has a detection angle range of, for example, approximately -30 degrees to 90 degrees. Optical sensor 4a obtains the maximum peak value of the detection sensitivity ratio at a detection angle of, for example, 0 degrees. Thus, optical sensor 4a mainly detects light incident from the right of the light detection device 1. Optical sensor 4b has a detection angle range of, for example, approximately -90 degrees to 30 degrees. Optical sensor 4b obtains the maximum peak value of the detection sensitivity ratio at a detection angle of 0 degrees. Optical sensor 4b mainly detects light incident from the left of the light detection device 1.

[0019] When there is no circuit board 2 used as a light-shielding body, the relationship between the sensitivity S1 of the optical sensor 4a, the sensitivity S2 of the optical sensor 4b, and the incident angle θ follows an ideal COS (cosine) curve. That is, the sensitivity S1 = sensitivity S2 = COSθ. The length of the shadow (d_shadow1) formed on the semiconductor chip 31 by the circuit board 2 on the left side of FIG. 1 is expressed as d_shadow1 = d1 × MAX(0, tan(-θ)). The length of the formed shadow covering the optical sensor 4a is d_shadow1 - d2. Therefore, the ratio of the area where no shadow is cast on the optical sensor 4a can be expressed as (d3 - d_shadow1 + d2) / d3 = (d3 - d1 × MAX(0, tan(-θ)) + d2) / d3. Thus, the relationship between the sensitivity S1 of the optical sensor 4a and the incident angle θ can be expressed as COSθ × (d3 - d1 × MAX(0, tan(-θ)) + d2) / d3. Similarly, the relationship between the sensitivity S2 of the optical sensor 4b and the incident angle θ can be expressed as COSθ × (d3 - d1 × MAX(0, tan(θ)) + d2) / d3.

[0020] In the optical sensors 4a and 4b, each optical sensor can detect the amount of light, and by analyzing the amounts of light detected by the plurality of optical sensors (the output values of each of the plurality of optical sensors), it is possible to specify the incident direction of the light.

[0021] The responsiveness (directional angle characteristics) of the optical sensors 4a and 4b with respect to the incident angle of light can be adjusted by the positional relationship between the window portion 21 provided on the circuit board 2 that blocks the light irradiated to the optical sensors 4a and 4b and the optical sensors �a and 4b. In this way, by controlling the directional angle characteristics of the optical sensors 4a and 4b, the light detection device 1 can detect the direction of light without adopting a double-molded structure including a light-shielding body and without securing additional space such as covering the optical device 3 with a transparent resin package.

[0022] Furthermore, it is preferable that each of the optical sensors 4a and 4b is positioned such that, for example, the second distance d2 is less than or equal to the first distance d1 (d2 ≤ d1). By positioning each of the optical sensors 4a and 4b in such a way that the second distance d2 is less than or equal to the first distance d1, the angle of light incident on a portion of the optical sensors 4a and 4b near the edge of the window portion 21 can be limited to 45 degrees or less.

[0023] Furthermore, it is preferable that each of the optical sensors 4a and 4b is positioned such that, for example, the second distance d2 is less than or equal to half of the first distance d1 (d2 ≤ d1 × 0.5). By positioning each of the optical sensors 4a and 4b in such a way that the second distance d2 is less than or equal to half of the first distance d1, the angle of light incident on a portion of the optical sensors 4a and 4b near the edge of the window portion 21 can be limited to approximately 26.56 degrees (tanθ = 0.5) or less.

[0024] Furthermore, it is preferable that each of the optical sensors 4a and 4b is positioned such that, for example, the sum of the second distance d2 and the third distance d3 is less than or equal to the first distance d1 ((d2+d3)≦d1). By positioning each of the optical sensors 4a and 4b in such a way that the sum of the second distance d2 and the third distance d3 is less than or equal to the first distance d1, the angle of light incident on the parts of the optical sensors 4a and 4b that are far from the edge of the window portion 21 can be limited to 45 degrees or less.

[0025] Furthermore, it is preferable that each of the optical sensors 4a and 4b is positioned such that, for example, the sum of the second distance d2 and the third distance d3 is less than or equal to half of the first distance d1 ((d2+d3)≦d1×0.5). By positioning each of the optical sensors 4a and 4b in such a way that the sum of the second distance d2 and the third distance d3 is less than or equal to half of the first distance d1, the angle of light incident on the parts of the optical sensors 4a and 4b that are far from the edge of the window portion 21 can be limited to approximately 26.56 degrees (tanθ=0.5) or less.

[0026] Furthermore, optical sensors 4a and 4b may be positioned such that the distance to the center of the sensor (d2 + (d3 / 2)) is less than or equal to the first distance d1, or they may be positioned such that the distance (d2 + (d3 / 2)) is less than or equal to half of the first distance d1.

[0027] In this way, the circuit board 2 can adjust the directional angle characteristics of optical sensors 4a and 4b by changing the position of the window portion 21 relative to optical sensors 4a and 4b. Although not shown, circuit elements that are electrically connected to the optical device 3 may be mounted on the circuit board 2. Furthermore, since the light detection device 1 uses the circuit board 2 to block the light irradiated onto optical sensors 4a and 4b without providing a separate light shield, it has a simple structure with the optical device 3 mounted on the circuit board 2, which allows for a reduction in the size of the device.

[0028] <Embodiment 2> Figure 4 is a cross-sectional view of the photodetector 1A according to Embodiment 2. Figure 5 is a plan view of the photodetector 1A according to Embodiment 2. Note that Figure 4 shows a plan view of the photodetector 1A as seen from the circuit board 2 side. Also, Figure 4 is a cross-sectional view of the IV-IV plane in Figure 5. As explained, the photodetector 1 according to Embodiment 1 has two optical sensors 4a and optical sensor 4b, but the photodetector 1A according to Embodiment 2 has even more optical sensors. In the photodetector 1A shown in Figures 4 and 5, the same reference numerals are used for components that are the same as those in the photodetector 1 shown in Figures 1 and 2, and detailed explanations are not repeated.

[0029] The light detection device 1A includes a circuit board 2 and an optical device 3A. The circuit board 2 is a mounting board for mounting the optical device 3A. The circuit board 2 has an upper surface (first surface) and an opposite lower surface (second surface), and the optical device 3A is mounted on the lower surface.

[0030] Optical device 3A is a semiconductor device equipped with optical sensors 4a, 4b, 4c, and 4d, and employs WLCSP. Specifically, optical device 3A has optical sensors 4a, 4b, 4c, and 4d, each composed of a photodiode or the like, formed on a semiconductor chip 31 (for example, a silicon chip). When the circuit board 2 is viewed from above, the shapes of optical sensors 4a to 4d are, for example, rectangular or square. Furthermore, on the surface of optical device 3A where optical sensors 4a to 4d are provided, electrode pads 32 are formed that are electrically connected to optical sensors 4a to 4d.

[0031] The optical device 3A is mounted on the circuit board 2 by a flip-chip connection with the side on which the electrode pads 32 are located facing the bottom surface of the circuit board 2. Specifically, the optical device 3A is electrically connected to the wiring (not shown) on the bottom surface of the circuit board 2 and the electrode pads 32 by solder 33. For this reason, a window portion 21 is provided in the circuit board 2 that penetrates the top and bottom surfaces, allowing light to be introduced to the optical sensors 4a to 4d facing the bottom surface of the circuit board 2.

[0032] As shown in Figure 5, when the circuit board 2 is viewed from above, optical sensors 4a and 4c are arranged sequentially from one edge of the rectangular window portion 21, and optical sensors 4b and 4d are arranged sequentially on the other edge of the window portion 21 opposite to the first edge. The light detection device 1A can detect the direction of light with respect to the direction of the optical sensors 4a to 4d arranged in a row. However, in order to detect the direction of light, the light detection device 1A needs to intentionally control the directional angle characteristics of the optical sensors 4a to 4d, and instead of providing a light shield, optical sensors 4a to 4d are arranged near the edge of the window portion 21 of the circuit board 2, as shown in Figure 4. In other words, the light detection device 1A uses the circuit board 2 as a light shield to control the directional angle characteristics of optical sensors 4a to 4d and detect the direction of light. Since the light detection device 1A has two more optical sensors than the light detection device 1 shown in Figure 1, it can detect the direction of light with greater precision.

[0033] In Figure 4, the distance from the surface on which optical sensors 4a to 4d are provided to the top surface of the circuit board 2 is defined as the first distance d1. When viewed from the top surface of the circuit board 2 in a plan view, the distance from the edge of the window portion 21 to one side of the optical sensor 4a and optical sensor 4b that are closest to it is defined as the second distance d2, and the length of one side of each optical sensor 4a and optical sensor 4b is defined as the third distance d3. Furthermore, the distance from the edge of the window portion 21 to one side of the optical sensor 4c and optical sensor 4d that are closest to it is defined as the fourth distance d4, and the length of one side of each optical sensor 4c and optical sensor 4d is defined as the fifth distance d5. In other words, the distance from the edge of the window portion 21 to one side of the optical sensor 4c and optical sensor 4d that are furthest from it is the fourth distance d4 + the fifth distance d5.

[0034] Specifically, the relationship between the detection angle and the detection sensitivity ratio of the light detection device 1A is determined by setting the first distance d1 to 500 μm, the second distance d2 to 100 μm, the third distance d3 to 200 μm, and the fourth distance d4 + fifth distance d5 to 1000 μm. Figure 6 is a diagram showing the relationship between the detection angle and the detection sensitivity ratio of the light detection device 1A according to Embodiment 2. In Figure 6, the detection angle is the angle of incidence of light with respect to the normal direction (detection angle = 0 degrees) of optical sensors 4a to 4d. Specifically, the detection angle is the angle of incidence θ with respect to the normal direction of optical sensor 4b shown in Figure 4, where the angle to the left is shown as a negative angle and the angle to the right is shown as a positive angle. In Figure 6, the detection sensitivity ratio is the ratio of the light ray amounts when the light ray amount when light is received from the normal direction is set to 1.0 for optical sensors 4a to 4d.

[0035] Figure 6 shows, as an example, detection examples of optical sensors 4a to 4d. In Figure 6, the detection characteristics of optical sensor 4a are shown by a solid line, the detection characteristics of optical sensor 4b are shown by a dashed line, the detection characteristics of optical sensor 4c are shown by a dashed line, and the detection characteristics of optical sensor 4d are shown by a double dashed line.

[0036] As shown in Figure 6, the optical sensor 4a has a detection angle range of, for example, approximately -30 degrees to 90 degrees. The optical sensor 4a obtains the maximum peak value of the detection sensitivity ratio at, for example, a detection angle of 0 degrees. Thus, the optical sensor 4a mainly detects light incident from the right of the light detection device 1A. The optical sensor 4c has a detection angle range of, for example, approximately -55 degrees to 90 degrees. The optical sensor 4c obtains the maximum peak value of the detection sensitivity ratio at, for example, a detection angle of 0 degrees. Thus, the optical sensor 4c detects light incident from the right of the light detection device 1A over a wider range than the optical sensor 4a.

[0037] As shown in Figure 6, the optical sensor 4b has a detection angle range of, for example, -90 degrees to approximately 30 degrees. The optical sensor 4b obtains the maximum peak value of its detection sensitivity ratio at a detection angle of 0 degrees. The optical sensor 4b mainly detects light incident from the left of the light detection device 1A. The optical sensor 4d has a detection angle range of, for example, -90 degrees to approximately 55 degrees. The optical sensor 4d obtains the maximum peak value of its detection sensitivity ratio at a detection angle of, for example, 0 degrees. Thus, the optical sensor 4d detects light incident from the left of the light detection device 1A over a wider range than the optical sensor 4b.

[0038] Similar to the relationship between the sensitivity S1 of optical sensor 4a and the sensitivity S2 of optical sensor 4b and the incident angle θ described in the light detection device 1 according to Embodiment 1, the relationship between the sensitivity S1 of optical sensor 4a to the sensitivity S4 of optical sensor 4d and the incident angle θ can be determined as follows: The relationship between the sensitivity S1 of optical sensor 4a and the incident angle θ can be expressed as COSθ × (d3 - d1 × MAX(0, tan(-θ)) + d2) / d3. The relationship between the sensitivity S2 of optical sensor 4b and the incident angle θ can be expressed as COSθ × (d3 - d1 × MAX(0, tan(θ)) + d2) / d3. The relationship between the sensitivity S3 of optical sensor 4c and the incident angle θ can be expressed as COSθ × (d5 - d1 × MAX(0, tan(-θ)) + d4) / d5. The relationship between the sensitivity S4 of the optical sensor 4d and the incident angle θ can be expressed as COSθ × (d5 - d1 × MAX(0, tan(θ)) + d4) / d5.

[0039] Optical sensors 4a to 4d can detect the amount of light, and by analyzing the amount of light detected by multiple optical sensors (the output values ​​of each optical sensor), it is possible to determine the direction of incident light. As shown in Figure 6, the light detection device 1A can detect the direction of light with more precision than the light detection device 1.

[0040] Furthermore, it is preferable that optical sensors 4c and 4d are positioned such that, for example, the sum of the fourth distance d4 and the fifth distance d5 (d4+d5) is approximately 1.732 times (=3^0.5) or less the first distance d1 ((d4+d5)≦d1×3^0.5). By positioning optical sensors 4c and 4d in such a way that the sum of the fourth distance d4 and the fifth distance d5 is approximately 1.732 times or less the first distance d1, the angle of light incident on the parts of optical sensors 4c and 4d that are far from the edge of the window portion 21 can be limited to approximately 60 degrees or less.

[0041] Furthermore, it is preferable that each of the optical sensors 4c and 4d be positioned such that the distance to the midpoint between them (d4 + (d5 / 2)) is approximately 1.732 times (=3^0.5) or less of the first distance d1 (d4 + (d5 / 2)) ≤ d1 × 3^0.5. By positioning each of the optical sensors 4c and 4d such that the distance to the midpoint between them is approximately 1.732 times (=3^0.5) or less of the first distance d1, the angle of light incident on the midpoint between the optical sensors 4c and 4d can be limited to approximately 60 degrees or less.

[0042] Furthermore, it is preferable that each of the optical sensors 4c and 4d be positioned such that, for example, the sum of the fourth distance d4 and the fifth distance d5 (d4+d5) is less than or equal to the first distance d1 ((d4+d5)≦d1). By positioning each of the optical sensors 4c and 4d in such a position where the sum of the fourth distance d4 and the fifth distance d5 is less than or equal to the first distance d1, the angle of light incident on the parts of the optical sensors 4c and 4d that are far from the edge of the window portion 21 can be limited to 45 degrees or less.

[0043] In this way, the circuit board 2 can adjust the directional angle characteristics of optical sensors 4a to 4d by changing the position of the window portion 21 relative to optical sensors 4a to 4d.

[0044] <Embodiment 3> Figure 7 is a cross-sectional view of the photodetector 1B according to Embodiment 3. Nothing is provided on the optical sensors 4a and 4b of the photodetector 1 according to Embodiment 1, nor on the optical sensors 4a to 4d of the photodetector 1A according to Embodiment 2. However, in the photodetector 1B according to Embodiment 3, a light-transmitting body 5 is formed to cover the upper surfaces of the optical sensors 4a to 4d. Note that in the photodetector 1B shown in Figure 7, the same reference numerals are used for components that are the same as those in the photodetector 1 shown in Figure 1 and the photodetector 1A shown in Figure 4, and detailed explanations will not be repeated.

[0045] The light-transmitting body 5 is formed to cover the upper surfaces of optical sensors 4a to 4d. A convex lens-shaped lens portion is provided in the center of the upper surface of the light-transmitting body 5, protruding upward. The lens portion of the light-transmitting body 5 has an upward-protruding shape, which allows it to collect more light from above the light detection device 1B and send it to the multiple sensors on optical sensors 4a to 4d.

[0046] The light-transmitting body 5 is integrally molded using, for example, a heat-resistant thermosetting resin such as a silicone-based or epoxy-based resin. In addition to a thermosetting resin, the light-transmitting body 5 may also be a curable resin such as an ultraviolet-curable resin. The light-transmitting body 5 may be provided so as to cover the upper surfaces of the optical sensors 4a and 4b of the light detection device 1 according to Embodiment 1, or so as to cover the upper surfaces of the optical sensors in the following modified examples.

[0047] <Variation> In the light detection devices 1, 1A, and 1B according to the embodiments described above, the optical sensors 4a and 4b, or optical sensors 4a to 4d, are arranged in a line to detect the direction of light in one dimension. However, the light detection device may also be configured to detect the direction of light in two dimensions by arranging multiple optical sensors on a plane. Figure 8 is a plan view of the light detection device 1C according to Modification 1. In the light detection device 1C shown in Figure 8, the same reference numerals are used for components that are the same as those in the light detection device 1 shown in Figure 2 and the light detection device 1A shown in Figure 5, and detailed explanations are not repeated.

[0048] Optical device 3C is a semiconductor device equipped with optical sensors 4a to 4d, and employs WLCSP. Specifically, optical device 3C has optical sensors 4a to 4d, which are composed of photodiodes and the like, formed on a semiconductor chip 31 (for example, a silicon chip). When the circuit board 2 is viewed from above, the shapes of optical sensors 4a to 4d are, for example, rectangular or square.

[0049] As shown in Figure 8, when the circuit board 2 is viewed from above, optical sensors 4a to 4d are positioned at the four corners of the rectangular window section 21. The light detection device 1C can detect the direction of light in two dimensions using the optical sensors 4a to 4d positioned at the four corners of the window section 21. However, in order to detect the direction of light, the light detection device 1C needs to intentionally control the responsiveness (direction angle characteristics) of the optical sensors 4a to 4d to the angle of incidence of light. Therefore, as shown in Figure 8, the light detection device 1C uses the circuit board 2 as a light shield by positioning the optical sensors 4a to 4d at the four corners of the window section 21 of the circuit board 2, thereby controlling the direction of light and detecting the direction of light.

[0050] The responsiveness (directional angle characteristics) of optical sensors 4a to 4d to the angle of incident light can be adjusted by the positional relationship between the window portion 21 provided on the circuit board 2 that blocks the light irradiated onto optical sensors 4a to 4d and the optical sensors 4a to 4d. Therefore, it is preferable that the positional relationship between each of the optical sensors 4a to 4d, which are arranged at the four corners of the window portion 21, and two sides of the edge of the adjacent window portion 21, satisfies the positional relationship between the edge of the window portion 21 and optical sensors 4a and 4b described in Embodiment 1. Note that the optical sensors provided on the optical device 3C are not limited to the four optical sensors 4a to 4d, and more optical sensors may be provided.

[0051] In the light detection device 1C according to Modification 1, optical sensors 4a to 4d are arranged at the four corners of the window portion 21 to detect the direction of light in two dimensions. However, the arrangement of optical sensors 4a to 4d is not limited to this. Figure 9 is a plan view of the light detection device 1D according to Modification 2. In the light detection device 1D shown in Figure 9, the same reference numerals are used for components that are the same as those in the light detection device 1 shown in Figure 2 and the light detection device 1A shown in Figure 5, and detailed explanations are not repeated.

[0052] The optical device 3D is a semiconductor device in which multiple optical sensors are arranged in a tile-like pattern, and utilizes WLCSP (Whole-Land Spectrometer Spatial Design). Specifically, the optical device 3D has optical sensors 4a to 4d and optical sensors 41 to 52, each composed of a photodiode or the like, formed on a semiconductor chip 31 (for example, a silicon chip). When the circuit board 2 is viewed from above, the shapes of the optical sensors 4a to 4d and optical sensors 41 to 52 are, for example, rectangular or square.

[0053] As shown in Figure 9, the optical device 3D has 4x4=16 optical sensors 4a to 4d and optical sensors 41 to 52 arranged in a tile pattern. When the circuit board 2 is viewed from above, rectangular window sections 21 are provided at the positions where optical sensors 4a to 4d are located. The light detection device 1D can detect the direction of light in two dimensions using the optical sensors 4a to 4d arranged in the window sections 21 and the optical sensors 41 to 52 arranged around optical sensors 4a to 4d.

[0054] However, in order to detect the direction of light, the light detection device 1D needs to intentionally control the responsiveness (direction angle characteristics) of optical sensors 4a to 4d and optical sensors 41 to 52 to the angle of incidence of light. Therefore, as shown in Figure 9, the light detection device 1D uses the circuit board 2 as a light shield to control the direction of light by controlling the direction of light by the optical sensors 4a to 4d and optical sensors 41 to 52.

[0055] <Note> The embodiment described above includes the following technical concept.

[0056] [Configuration 1] A circuit board having a first surface and a second surface opposite to the first surface, with a window portion provided that penetrates the first surface and the second surface, An optical device having multiple optical sensors, the surface on which the multiple optical sensors are provided is mounted on the second surface of the circuit board facing the second surface of the circuit board, and comprising The plurality of optical sensors are arranged at different positions within a range in which they can receive light incident from the first surface side of the circuit board through the window portion. The optical device is a light detection device that detects the direction of light based on the output values ​​of each of the plurality of optical sensors.

[0057] By adopting this configuration, it is possible to provide a light detection device that reduces design man-hours and manufacturing costs, and enables miniaturization of the device.

[0058] [Configuration 2] The optical device is a semiconductor device on which the plurality of optical sensors are formed, and is mounted on the circuit board by flip-chip connection, as described in Configuration 1.

[0059] By adopting this configuration, it is possible to provide a light detection device that can be miniaturized.

[0060] [Configuration 3] The distance from the surface on which the plurality of optical sensors are provided to the first surface of the circuit board is defined as the first distance, and the distance from the edge of the window portion to one side of each of the plurality of optical sensors closest to it when viewed from the first surface of the circuit board is defined as the second distance. The optical detection device according to configuration 1 or configuration 2, wherein each of the plurality of optical sensors is positioned such that the second distance is less than or equal to the first distance.

[0061] By adopting this configuration, it is possible to provide a light detection device that reduces design man-hours and manufacturing costs without requiring a light shield, and that can be made smaller.

[0062] [Configuration 4] The distance from the surface on which the plurality of optical sensors are provided to the first surface of the circuit board is defined as the first distance, and the distance from the edge of the window portion to one side of each of the plurality of optical sensors closest to it when viewed from the first surface of the circuit board is defined as the second distance. The light detection device according to configuration 1 or configuration 2, wherein each of the plurality of optical sensors is positioned such that the second distance is half or less of the first distance.

[0063] By adopting this configuration, it is possible to provide a light detection device that reduces design man-hours and manufacturing costs without requiring a light shield, and that can be made smaller.

[0064] [Configuration 5] The distance from the surface on which the plurality of optical sensors are provided to the first surface of the circuit board is defined as the first distance, the distance from the edge of the window to the side of each of the plurality of optical sensors closest to it when viewed from the first surface of the circuit board is defined as the second distance, and the distance between the edge of the window and the side of each of the plurality of optical sensors furthest from it is defined as the third distance. The optical detection device according to configuration 1 or configuration 2, wherein each of the plurality of optical sensors is positioned such that the sum of the second distance and the third distance is less than or equal to the first distance.

[0065] By adopting this configuration, it is possible to provide a light detection device that reduces design man-hours and manufacturing costs without requiring a light shield, and that can be made smaller.

[0066] [Configuration 6] The distance from the surface on which the plurality of optical sensors are provided to the first surface of the circuit board is defined as the first distance, the distance from the edge of the window to the side of each of the plurality of optical sensors closest to it when viewed from the first surface of the circuit board is defined as the second distance, and the distance between the edge of the window and the side of each of the plurality of optical sensors furthest from it is defined as the third distance. The light detection device according to configuration 1 or configuration 2, wherein each of the plurality of optical sensors is positioned such that the sum of the second distance and the third distance is less than or equal to half of the first distance.

[0067] By adopting this configuration, it is possible to provide a light detection device that reduces design man-hours and manufacturing costs without requiring a light shield, and that can be made smaller.

[0068] [Configuration 7] The plurality of optical sensors include a first optical sensor and a second optical sensor, The first optical sensor is positioned on one edge side of the window portion, The light detection device according to any one of configurations 1 to 6, wherein the second optical sensor is positioned on the other edge side facing one edge of the window portion.

[0069] This configuration allows for the one-dimensional detection of the direction of light with respect to the direction in which the first optical sensor and the second optical sensor are located.

[0070] [Configuration 8] The plurality of optical sensors further comprises a third optical sensor and a fourth optical sensor, The third optical sensor is positioned close to the first optical sensor on a straight line where the first optical sensor and the second optical sensor are aligned. The light detection device according to configuration 7, wherein the fourth optical sensor is positioned close to the second optical sensor on a straight line where the first optical sensor and the second optical sensor are aligned.

[0071] This configuration allows for precise detection of the direction of light using the third and fourth optical sensors.

[0072] [Configuration 9] The plurality of optical sensors have four optical sensors, The four optical sensors are arranged at the four corners of the window portion, in a light detection device according to any of configurations 1 to 6.

[0073] This configuration allows for the detection of the direction of light in two dimensions using four optical sensors.

[0074] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols]

[0075] 1, 1A~1D: Light detection device, 2: Circuit board, 3, 3A, 3C, 3D: Optical device, 4a~4d, 41~52: Optical sensor, 5: Light-transmitting material, 21: Window section, 31: Semiconductor chip, 32: Electrode pad, 33: Solder.

Claims

1. A circuit board having a first surface and a second surface opposite to the first surface, with a window portion provided that penetrates the first surface and the second surface, An optical device having multiple optical sensors, the surface on which the multiple optical sensors are provided is mounted on the second surface of the circuit board facing the second surface of the circuit board, and comprising The plurality of optical sensors are arranged at different positions within a range in which they can receive light incident from the first surface side of the circuit board through the window portion. The optical device is a light detection device that detects the direction of light based on the output values ​​of each of the plurality of optical sensors.

2. The optical device is a semiconductor device on which the plurality of optical sensors are formed, and is mounted on the circuit board by flip-chip connection, as described in claim 1.

3. The distance from the surface on which the plurality of optical sensors are provided to the first surface of the circuit board is defined as the first distance, and the distance from the edge of the window portion to one side of each of the plurality of optical sensors closest to it, when viewed from the first surface of the circuit board in plan view, is defined as the second distance. The light detection device according to claim 1 or claim 2, wherein each of the plurality of optical sensors is positioned such that the second distance is less than or equal to the first distance.

4. The distance from the surface on which the plurality of optical sensors are provided to the first surface of the circuit board is defined as the first distance, and the distance from the edge of the window portion to one side of each of the plurality of optical sensors closest to it, when viewed from the first surface of the circuit board in plan view, is defined as the second distance. The light detection device according to claim 1 or claim 2, wherein each of the plurality of optical sensors is positioned such that the second distance is half or less of the first distance.

5. The distance from the surface on which the plurality of optical sensors are provided to the first surface of the circuit board is defined as the first distance, the distance from the edge of the window to the side of each of the plurality of optical sensors closest to it when viewed from the first surface of the circuit board is defined as the second distance, and the distance from the edge of the window to the side of each of the plurality of optical sensors furthest from it is defined as the third distance. The light detection device according to claim 1 or claim 2, wherein each of the plurality of optical sensors is positioned such that the sum of the second distance and the third distance is less than or equal to the first distance.

6. The distance from the surface on which the plurality of optical sensors are provided to the first surface of the circuit board is defined as the first distance, the distance from the edge of the window to the side of each of the plurality of optical sensors closest to it when viewed from the first surface of the circuit board is defined as the second distance, and the distance from the edge of the window to the side of each of the plurality of optical sensors furthest from it is defined as the third distance. The light detection device according to claim 1 or claim 2, wherein each of the plurality of optical sensors is positioned such that the sum of the second distance and the third distance is less than or equal to half of the first distance.

7. The plurality of optical sensors include a first optical sensor and a second optical sensor. The first optical sensor is positioned on one edge side of the window portion, The light detection device according to claim 1 or claim 2, wherein the second optical sensor is arranged on the other edge side of the window portion opposite to one edge.

8. The aforementioned plurality of optical sensors further comprises a third optical sensor and a fourth optical sensor, The third optical sensor is positioned close to the first optical sensor on a straight line where the first optical sensor and the second optical sensor are aligned. The light detection device according to claim 7, wherein the fourth optical sensor is positioned close to the second optical sensor on a straight line where the first optical sensor and the second optical sensor are aligned.

9. The aforementioned plurality of optical sensors have four optical sensors, The light detection device according to claim 1 or claim 2, wherein the four optical sensors are arranged at the four corners of the window portion.

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