Light detection device

Abstract

SOLUTION: A light detection device is provided that comprises: a packaging substrate; and a light sensor device that has a first face on a packaging substrate side and a second face on a side opposite the packaging substrate, and is mounted in the packaging substrate. The light sensor device has: a light sensor that has a light receiving face on a second face side; a signal processing circuit that is electrically connected to the light sensor; and a lead frame that is provided on the second face side with respect to the signal processing circuit, and shields a face on the second face side in the signal processing circuit, and the packaging substrate has a conducive pattern that faces the signal processing circuit, and shields a face on a first face side in the signal processing circuit.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an optical detection device.

Background Art

[0002] Patent Document 1 describes that "as shown in FIGS. 1(a) to 1(d), the infrared sensor member 50 includes a third member 41 having a through opening h2 and a die pad 42, an IR sensor element 43 disposed in the opening h2 of the third member 41, a signal processing IC 44 attached to one surface side (i.e., the surface 41a side) of the die pad 42, wires 45 made of gold (Au) or the like that electrically connect between the IR sensor element 43 and the third member 41, between the signal processing IC 44 and the third member 41, and between the IR sensor element 43 and the signal processing IC 44, and a molding member 46 that covers the third member 41, the IR sensor element 43, the signal processing IC 44, and the wires 45." [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent No. 6039789

Summary of the Invention

[0003] In an aspect of the present invention, an optical detection device is provided. The optical detection device may include a mounting substrate. The optical detection device has a first surface on the mounting substrate side and a second surface opposite to the mounting substrate, and may include an optical sensor device mounted on the mounting substrate. The optical sensor device may include an optical sensor having a light receiving surface on the second surface side. The optical sensor device may include a signal processing circuit electrically connected to the optical sensor. The optical sensor device may include a lead frame provided on the second surface side with respect to the signal processing circuit and shielding the surface on the second surface side of the signal processing circuit. The mounting substrate may face the signal processing circuit and may include a conductive pattern shielding the surface on the first surface side of the signal processing circuit.

[0004] The signal processing circuit may be disposed between the lead frame and the conductive pattern and may have an area smaller than that of the lead frame and the conductive pattern when viewed from the light receiving surface side.

[0005] The lead frame may have an opening to expose the light-receiving surface of the optical sensor to the outside.

[0006] The light sensor is a back-facing light-receiving type and may have a circuit surface on the mounting board side.

[0007] The light sensor may be an infrared sensor.

[0008] The signal processing circuit may be an integrated circuit chip having a circuit surface on the mounting board side.

[0009] The lead frame may be electrically connected to the conductive pattern.

[0010] The lead frame may have a single terminal that is electrically connected to the conductive pattern.

[0011] The lead frame may have two or more terminals that are electrically connected to the conductive pattern.

[0012] The conductive pattern may be electrically connected to the ground of the mounting board.

[0013] The lead frame may have multiple terminals provided at intervals of 2.85 mm or less on at least a portion of the edge of the optical sensor device.

[0014] The conductive pattern may be provided on the surface of the mounting substrate that is on the side facing the optical sensor device.

[0015] The conductive pattern may be provided on at least one of the inner layers of the mounting substrate or on the surface of the mounting substrate opposite to the optical sensor device.

[0016] The conductive pattern may be positioned further opposite the light sensor, further shielding the first surface of the light sensor.

[0017] The lead frame can be thicker than the conductive pattern.

[0018] The optical sensor device may have a structure in which an optical sensor, a signal processing circuit, and a lead frame are integrated by resin encapsulation.

[0019] Note that the above summary of the invention does not enumerate all the features of the present invention. Also, sub-combinations of these feature groups can also be inventions.

Brief Description of the Drawings

[0020] [Figure 1] Shows the structure of the optical sensor device 100 according to this embodiment. [Figure 2] Shows the internal structure of the sensor block 110 according to this embodiment. [Figure 3] It is a schematic diagram of a cross-section of the sensor block 110 according to this embodiment. [Figure 4] It is a schematic diagram of a cross-section of the photodetection device 400 according to this embodiment. [Figure 5] It is a perspective view of the mounting substrate 410 according to this embodiment. [Figure 6] It is a perspective view of the photodetection device 400 according to this embodiment. [Figure 7] Shows the structure of the photodetection device 700 according to the first modification of this embodiment. [Figure 8] Shows the structure of the photodetection device 800 according to the second modification of this embodiment. [Figure 9] Shows the structure of the photodetection device 900 according to the third modification of this embodiment. [Figure 10] Shows the structure of the photodetection device 1000 according to the fourth modification of this embodiment. [Figure 11] Shows the structure of the photodetection device 1100 according to this embodiment. [Figure 12] Shows an example of the thickness of each part of the photodetection device 400 according to this embodiment. [Figure 13] Shows the plate structure 1300 according to the fifth modification of this embodiment.

Embodiments for Carrying Out the Invention

[0021] The present invention will be described below through embodiments, but these embodiments are not intended to limit the scope of the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0022] Figure 1 shows the structure of the optical sensor device 100 according to this embodiment, viewed from the top, bottom, long side, and short side. The optical sensor device 100 receives light and converts it into an electrical signal. In this embodiment, the optical sensor device 100 is, as an example, an infrared sensor device that receives infrared light and converts it into an electrical signal. Alternatively, the optical sensor device 100 may receive light of other wavelengths and convert it into an electrical signal. Here, for the sake of explanation, the side of the optical sensor device 100 or the sensor block 110 of the optical sensor device 100 that is mounted on the mounting substrate is referred to as the "bottom surface," "first surface," or "mounting surface," and the side of the optical sensor device 100 or the sensor block 110 that receives light is referred to as the "top surface," "second surface," or "light-receiving surface."

[0023] The optical sensor device 100 comprises a sensor block 110 and a filter block 140. The sensor block 110 has a lead frame 120 and incorporates an optical sensor and signal processing circuit as shown in Figure 2 and subsequent figures.

[0024] The lead frame 120 supports or fixes the built-in devices (IC, LSI, or ASIC, etc.) such as the optical sensor and signal processing circuit within the optical sensor device 100, and functions as a terminal for electrically connecting the built-in devices within the optical sensor device 100 to external wiring. The lead frame 120 is formed by etching or pressing a metal plate such as copper. In this embodiment, the lead frame 120 is exposed on the upper surface of the sensor block 110. The lead frame 120 also has a plurality of terminals 130 on at least some or all of the sides of the sensor block 110. Each terminal 130 is exposed from the upper surface to the side and lower surface of the sensor block 110 and is connected to a terminal pattern on the mounting substrate on the lower surface of the sensor block 110. Some of the terminals 130 (in this embodiment, two terminals each on the upper and lower sides in the top view, and the 1st, 2nd, and 7th terminals from the top on the right and left sides) are connected to a rectangular plate portion of the lead frame 120 that is widely exposed on the upper side of the sensor block 110.

[0025] The filter block 140 is fixedly positioned on the upper surface of the sensor block 110, above the optical sensor of the sensor block 110. The filter block 140 allows light in the wavelength band that the optical sensor device 100 should receive to pass through, while filtering out light of wavelengths outside that band. Here, the optical sensor may be an infrared sensor as an example, and the filter block 140 may allow infrared light to pass through. In this embodiment, the optical sensor device 100 is equipped with the filter block 140, but the optical sensor device 100 may also be configured without the filter block 140.

[0026] Figure 2 shows the internal structure of the optical sensor device 100 according to this embodiment, viewed from the bottom. The lead frame 120 has a thickness from the top to the bottom of the sensor block 110 where each terminal 130 is provided on the edge of the sensor block 110. On the other hand, the lead frame 120 forms the bottom of a recessed area when viewed from the bottom of the sensor block 110 and includes a rectangular plate portion that is widely exposed on the top side of the sensor block 110.

[0027] The lead frame 120 has a structure in which a metal plate having the same thickness as the terminals 130 is partially removed by etching or the like from the mounting surface side toward the light-receiving surface side, except for the portion of the terminals 130 that is exposed on the mounting surface, thereby forming a recess, and a rectangular plate portion thinner than the terminals 130 is formed at the bottom of the recess. The area hatched with diagonal lines in Figure 2 indicates the recess carved out by etching or press working. In the area hatched with diagonal lines in the figure, the lead frame 120 is exposed on the upper surface side of the sensor block 110, but it is thinner than the area where each terminal 130 is provided, and there is a gap between it and the lower surface side of the sensor block 110.

[0028] Furthermore, the multiple terminals 130 on the lead frame 120 are separated by completely removing the space between them through etching or the like. For each terminal 130 that is not electrically connected to the rectangular plate portion, the space between the rectangular plate portion on the metal plate and that terminal 130 is completely removed by etching or the like to separate them. In the figure, of the multiple terminals 130, the two terminals on the top and bottom edges of the sensor block 110, and the 1st, 2nd, and 7th terminals from the top on the right and left edges are electrically connected to the rectangular plate portion. In the figure, the 3rd to 6th terminals on the right and left edges of the sensor block 110 are disconnected from the rectangular plate portion.

[0029] The sensor block 110 includes an optical sensor 200 and a signal processing circuit 210. The lead frame 120 has an opening 205 for exposing the light-receiving surface of the optical sensor 200 to the outside of the sensor block 110, and the optical sensor 200 is positioned within the opening 205 with its light-receiving surface facing the upper side in Figure 1.

[0030] The signal processing circuit 210 is positioned on the lower surface of the sensor block 110 in the lead frame 120. The signal processing circuit 210 is electrically connected to the light sensor 200 and some of the multiple terminals 130 by wire bonding or the like. The signal processing circuit 210 processes the electrical signal output by the light sensor 200 in response to light reception and outputs a detection signal from at least one terminal 130 that indicates a digital value corresponding to the light intensity, for example.

[0031] As described above, the lead frame 120 covers the upper side of the signal processing circuit 210 more broadly than the signal processing circuit 210 itself, thus shielding the upper side of the signal processing circuit 210 from external noise.

[0032] Figure 3 is a schematic diagram of the cross-section of the sensor block 110 according to this embodiment, corresponding to A-A' in Figure 2. In this figure, side A in Figure 2 is the left side of the page, and side A' is the right side of the page. Also, in this figure, the light-receiving surface of the sensor block 110 is the bottom side of the page, and the mounting surface of the sensor block 110 to the mounting substrate is the top side of the page.

[0033] The rectangular plate portion of the lead frame 120 is exposed on the light-receiving surface side of the sensor block 110. As shown in Figures 2 and 3, the lead frame 120 has an opening 205, which is a through hole provided in the rectangular plate portion. The light sensor 200 is positioned in the opening 205 such that its light-receiving surface is flush with the lower surface of the lead frame 120. In this embodiment, the light sensor 200 is a back-side light-receiving type and has its circuit surface on the opposite side of the light-receiving surface (the mounting substrate side), i.e., on the upper side of the paper. The signal processing circuit 210 is positioned on the mounting substrate side of the lead frame 120. In this embodiment, the signal processing circuit 210 is an integrated circuit chip with its circuit surface on the mounting substrate side.

[0034] In this embodiment, as described above, both the optical sensor 200 and the signal processing circuit 210 have circuit surfaces on the mounting substrate side. The circuit surface of the optical sensor 200 and the circuit surface of the signal processing circuit 210 are connected by wire bonding.

[0035] The manufacturing method for the optical sensor device 100 is as follows, as an example. First, a lead frame 120 having multiple terminals 130 and an opening 205 is formed on a metal plate by etching or pressing the area that should be included in the sensor block 110. Next, adhesive tape is attached to the lower side of the lead frame 120, and the optical sensor 200 is placed in the opening 205 and fixed to the adhesive tape.

[0036] Next, the signal processing circuit 210 is attached to the upper surface of the lead frame 120 in Figure 3 using adhesive or adhesive tape. Then, the terminals on the circuit surface of the optical sensor 200 and the aperture 205 are electrically connected by wire bonding. Next, the lead frame 120, optical sensor 200, and signal processing circuit 210 are sealed by molding. Finally, the adhesive tape that secures the lead frame 120 and optical sensor 200 is removed.

[0037] As an example, by using such a manufacturing method, an optical sensor device 100 having a structure in which the optical sensor 200, signal processing circuit 210, and lead frame 120 are integrated by resin encapsulation can be manufactured.

[0038] Figure 4 is a schematic cross-sectional view of the photodetector 400 according to this embodiment, corresponding to the section B-B' in Figure 2. The photodetector 400 comprises a photosensor device 100 and a mounting substrate 410 on which the photosensor device 100 is arranged. Note that the filter block 140 of the photosensor device 100 is omitted in this figure.

[0039] The optical sensor device 100 has a mounting surface (first surface) on the mounting substrate 410 side and a light-receiving surface (second surface) on the opposite side of the mounting substrate 410, and is mounted on the mounting substrate 410. The optical sensor device 100 includes a lead frame 120 exposed on the light-receiving surface side (upper side of the paper in the figure) and a signal processing circuit 210 arranged on the mounting surface side of the lead frame 120 inside a recess formed from the mounting surface side. The lead frame 120 is provided on the light-receiving surface side relative to the signal processing circuit 210 and shields the light-receiving surface of the signal processing circuit 210.

[0040] The mounting board 410 supports and fixes various electronic components, including the optical sensor device 100. The mounting board 410 has wiring patterns and electrically connects the electronic components. The mounting board 410 may be any type of board capable of mounting the optical sensor device 100, such as a printed circuit board (PCB), a board included in each stacked package in a package-on-package (PoP), or an interposer inserted between an electronic device and a printed circuit board, etc., to convert terminal arrangements between them.

[0041] The mounting substrate 410 has a conductive pattern 420 and one or more conductive patterns 430 on the mounting surface side of the optical sensor device 100 on the insulating substrate body. For example, the conductive pattern 420 and one or more conductive patterns 430 may be formed by etching away areas other than the desired pattern portion of a thin metal film such as copper foil formed on the insulating substrate body. The conductive pattern 420 is provided on the mounting surface side of the mounting substrate 410 on the optical sensor device 100, at a position facing the rectangular plate portion of the lead frame 120 and the signal processing circuit 210. The conductive pattern 420 may be provided on the surface of the mounting substrate 410 on the optical sensor device 100 side. The conductive pattern 420 shields the surface of the signal processing circuit 210 on the mounting surface side of the optical sensor device 100. One or more conductive patterns 430 are each provided at a position facing the corresponding terminal 130 of the optical sensor device 100 and are connected to the corresponding terminal 130.

[0042] According to the photodetector 400 described above, the signal processing circuit 210 is positioned between the lead frame 120 and the conductive pattern 420. Here, the signal processing circuit 210 has a smaller area than either the lead frame 120 or the rectangular plate portion of the lead frame 120, or the conductive pattern 420, when viewed from the light-receiving side of the photosensor device 100. As a result, the signal processing circuit 210 can be shielded from external sources on both the light-receiving side and the mounting side of the photosensor device 100, and thus can be protected from noise. Furthermore, the photodetector 400 shields the light-receiving surface of the photosensor device 100 in the signal processing circuit 210 with a lead frame 120 built into the photosensor device 100, and shields the mounting surface of the photosensor device 100 in the signal processing circuit 210 with a conductive pattern 420 formed on the mounting substrate 410 outside the photosensor device 100. This simplifies the structure of the photosensor device 100 compared to shielding the top and bottom of the signal processing circuit 210 within the photosensor device 100.

[0043] As shown in Figures 1 and 2, the optical sensor device 100 has multiple terminals 130 spaced apart. Even with this configuration, noise from the sides where the spacing between terminals is less than or equal to half the wavelength can be blocked or sufficiently reduced. Therefore, the multiple terminals 130 included in at least a portion of the edges of the lead frame 120 may be spaced at intervals of 2.85 mm or less. This allows the optical sensor device 100 to block or sufficiently reduce noise in the bandwidth of 52.6 GHz or less, where the wavelength is less than or equal to twice 2.85 mm, which is used for communication.

[0044] Furthermore, the photodetector 400 uses a photosensor device in which a lead frame is placed on the mounting surface side and a signal processing circuit is placed on the light-receiving surface side of the lead frame. Instead of employing a structure that covers the light-receiving side with a conductive cover or conductive tape while leaving an opening for the photosensor, the shield is formed using the lead frame 120 and the conductive pattern 420 of the mounting substrate 410. Therefore, the photodetector 400 can form a shield during the process of mounting the photosensor device 100 on the mounting substrate 410 having the conductive pattern 420 by reflow, without using a photosensor device that shields both the light-receiving side and the mounting surface side.

[0045] Figure 5 is a perspective view of the mounting substrate 410 according to this embodiment, and Figure 6 is a perspective view of the light detection device 400 according to this embodiment. In this embodiment, a conductive pattern 420 and one or more conductive patterns 430 are formed on the mounting surface side of the substrate body of the mounting substrate 410 for the light sensor device 100. The conductive pattern 420 has a rectangular pattern facing the rectangular plate portion of the lead frame 120 and the signal processing circuit 210. As shown in Figures 5 and 6, the conductive pattern 420 may further face the light sensor 200 and further shield the surface of the light sensor 200 on the mounting substrate 410 side (first surface side).

[0046] As shown in Figure 5, the conductive pattern 420 may have at least one terminal pattern connected to at least one terminal (such as a ground terminal) of the optical sensor device 100. As shown in Figure 6, each terminal 130 of the optical sensor device 100 may be connected to a conductive pattern 430 which is a corresponding terminal pattern on the optical detection device 400.

[0047] In the photodetector 400 according to this embodiment, the lead frame 120 may be electrically connected to the conductive pattern 420 via at least one terminal 130. Here, the conductive pattern 420 may have a predetermined potential, and the rectangular plate portion of the lead frame 120 may be connected to the conductive pattern 420 and be at approximately the same potential as the conductive pattern 420. For example, the conductive pattern 420 may be electrically connected to the ground of the mounting substrate 410, and the rectangular plate portion of the lead frame 120 and the conductive pattern 420 may be at the ground potential. Alternatively, the rectangular plate portion of the lead frame 120 and the conductive pattern 420 may be at the power supply potential, or an intermediate potential between the ground and the power supply potential. Alternatively, the rectangular plate portion of the lead frame 120 and the conductive pattern 420 may be connected to different fixed potentials (e.g., ground potential and power supply potential). Furthermore, at least one of the rectangular plate portion of the lead frame 120 and the conductive pattern 420 may not be connected to a fixed potential and may be at a floating potential.

[0048] Figure 7 shows the structure of a photodetector 700 according to the first modified example of this embodiment. In this modified example, the photodetector 700 has a configuration in which the photosensor device 100 shown in Figures 1 to 3 is mounted on a mounting substrate 710 instead of the mounting substrate 410 shown in Figures 4 to 6.

[0049] The mounting substrate 710 has a conductive pattern 720 corresponding to the conductive pattern 420 on the mounting substrate 410, and conductive patterns 730a to 730b corresponding to the conductive pattern 430. Below, the differences between conductive patterns 720 and 730a to 730b and conductive patterns 420 and 430 will be explained, while the similarities between conductive patterns 420 and 430 will not be explained.

[0050] The conductive pattern 720 is provided on an inner layer of the mounting substrate 710, rather than on the surface of the mounting substrate 710 facing the optical sensor device 100. Even when the conductive pattern 720 is provided on an inner layer of the mounting substrate 710, it can broadly cover and shield the surface of the signal processing circuit 210 facing the mounting surface of the optical sensor device 100. Alternatively, or in addition to this, the conductive pattern 720 may be provided on the surface of the mounting substrate 710 opposite to the optical sensor device 100.

[0051] In the example shown in this figure, the mounting substrate 710 has one or more conductive patterns 730a to b corresponding to at least one terminal 130 of the optical sensor device 100 that is connected to the rectangular plate portion of the lead frame 120. As shown in this figure, the conductive pattern 720 may be connected to at least one conductive pattern 730a via conductive vias. In addition, the conductive pattern 720 may be formed so that the conductive patterns face each other with respect to at least one conductive pattern 730b, and may be electrically coupled with such conductive pattern 730b by capacitive coupling (parasitic capacitor).

[0052] Figure 8 shows the structure of a photodetector 800 according to a second modified example of this embodiment. In this modified example, the photodetector 800 has a configuration in which the photosensor device 100 shown in Figures 1 to 3 is mounted on a mounting substrate 810 instead of the mounting substrate 710 shown in Figure 7.

[0053] The mounting substrate 810 has a conductive pattern 820 corresponding to the conductive pattern 720 on the mounting substrate 710, and conductive patterns 830a to b corresponding to conductive patterns 730a to b. Below, the differences between conductive patterns 820 and 830a to b and conductive patterns 720 and 730a to b will be explained, and conductive patterns 720 and 730a to b will be explained. a I will omit the explanation of the similarities with ~b.

[0054] The conductive pattern 820 is provided in the inner layer of the mounting substrate 810. The conductive pattern 820 broadly covers and shields the mounting side of the optical sensor device 100 in the signal processing circuit 210. In the example shown in this figure, the mounting substrate 810 has one or more conductive patterns 830a to b corresponding to terminals 130 of the optical sensor device 100 that are connected to the rectangular plate portion of the lead frame 120. As shown in this figure, the conductive pattern 820 may be connected to at least one conductive pattern 830a via conductive vias. Alternatively, the conductive pattern 820 may be formed in the inner layer of the mounting substrate 810 with respect to at least one conductive pattern 830b, or connected to conductive pattern 830b via electronic components such as a capacitor 840 mounted on the mounting substrate 810. Such electronic components may be other electronic components such as resistors or coils.

[0055] Figure 9 shows the structure of a photodetector 900 according to a third modified example of this embodiment. In this modified example, the photodetector 900 has a configuration in which the photosensor device 100 shown in Figures 1 to 3 is mounted on a mounting substrate 910 instead of the mounting substrate 410 shown in Figures 4 to 6.

[0056] The mounting substrate 910 has a conductive pattern 920 that corresponds to the conductive pattern 420 on the mounting substrate 410. Below, the differences between the conductive pattern 920 and the conductive pattern 420 will be explained, while the similarities with the conductive pattern 420 will not be explained.

[0057] In this modified example, the lead frame 120 has a single terminal 130 that is electrically connected to the conductive pattern 920, and the rectangular plate portion of the lead frame 120 is connected to the conductive pattern 920 via this terminal 130. The conductive pattern 920 may be connected to a fixed potential such as ground, similar to the conductive pattern 420.

[0058] In this modified photodetector 900, the lead frame 120 is connected to the conductive pattern 920 at a single point. Therefore, the photodetector 900 does not have a loop structure that can generate resonance such as a ground loop, and the fixed potential can be stabilized.

[0059] Figure 10 shows the structure of a photodetector 1000 according to a fourth modified example of this embodiment. In this modified example, the photodetector 1000 has a configuration in which the photosensor device 100 shown in Figures 1 to 3 is mounted on a mounting substrate 1010 instead of the mounting substrate 410 shown in Figures 4 to 6.

[0060] The mounting substrate 1010 has a conductive pattern 1020 that corresponds to the conductive pattern 420 on the mounting substrate 410. Below, the differences between the conductive pattern 1020 and the conductive pattern 420 will be explained, while the similarities with the conductive pattern 420 will not be explained.

[0061] In this modified example, the lead frame 120 has two or more terminals 130 that are electrically connected to the conductive pattern 1020, and the rectangular plate portion of the lead frame 120 is connected to the conductive pattern 1020 via these two or more terminals 130. In this example, two or more terminals 130 located on two opposing sides of the optical sensor device 100 are connected to the conductive pattern 1020. The conductive pattern 1020 may be connected to a fixed potential such as ground, similar to the conductive pattern 420.

[0062] In the modified photodetector 1000, the rectangular plate portion of the lead frame 120 is connected to the conductive pattern 1020 at two or more points, forming a loop structure such as a ground loop. On the other hand, since the rectangular plate portion of the lead frame 120 is connected to the conductive pattern 1020 at multiple points, when the fixed potential of the conductive pattern 1020 is sufficiently suppressed, the photodetector 1000 can further stabilize the potential of the rectangular plate portion of the lead frame 120.

[0063] Figure 11 shows the structure of the photodetector 1100 according to this embodiment. The photodetector 1100 may be, for example, a light-based gaseous component detection device such as an alcohol detection device. The photodetector 1100 comprises a plurality of photosensor devices 100a to 100b, a mounting substrate 1110, and a cover 1115. In this embodiment, the photosensor device 100a has a sensor block 110a and a filter block 140a, and the photosensor device 100b has a sensor block 110b and a filter block 140b. Each of the photosensor devices 100a to 100b is the same as the photosensor device 100 shown in Figures 1 to 3, except that the wavelength bands through which light is passed in the filter blocks 140a and 140b differ from each other, so the following explanation will be omitted except for the differences.

[0064] The mounting board 1110 mounts a plurality of optical sensor devices 100a to b (also referred to as "optical sensor device 100"). The mounting board 1110 has conductive patterns 1120a and one or more conductive patterns 1130a for mounting optical sensor device 100a, and conductive patterns 1120b and one or more conductive patterns 1130b for mounting optical sensor device 100b. Here, the mounting board 1110 corresponds to the mounting board 410 shown in Figures 4 to 6, and conductive patterns 1120a to b (also referred to as "conductive pattern 1120") are the same as conductive pattern 420, and conductive patterns 1130a to b (also referred to as "conductive pattern 1130") are the same as conductive pattern 430, so the explanation will be omitted below except for the differences.

[0065] The cover 1115 is provided on the mounting surface side of the mounting substrate 1110 for the multiple optical sensor devices 100a to b, and covers the multiple optical sensor devices 100a to b. The cover 1115 may have an opening for taking in outside air into the space between the cover 1115 and the optical sensor devices 100a to b.

[0066] The photodetector 1100 detects light generated from an infrared light source (not shown) using photosensor devices 100a and 100b. Here, photosensor device 100a has a filter block 140a that selectively passes one of the infrared absorption bands absorbed by the gas to be detected, and photosensor device 100b has a filter block 140b that selectively passes one of the other infrared absorption bands absorbed by the gas to be detected. Therefore, when the concentration of the gas to be detected increases, photosensor devices 100a and 100b reduce the output value of the detection signal, which represents the intensity of the light.

[0067] A detection circuit (not shown) mounted on the mounting substrate 1110 detects the presence of a gas to be detected when the detection signals from the optical sensor devices 100a to 100b fall below their respective thresholds. According to the optical detection device 1100 of this embodiment, by providing a signal processing circuit 210 between the lead frame 120 on the light-receiving surface side of each of the multiple optical sensor devices 100 and the conductive pattern 1120 of the mounting substrate 1110, it is possible to prevent external noise from being applied to the signal processing circuit 210.

[0068] Figure 12 shows an example of the thickness of each part of the light detection device 400 according to this embodiment. Here, Figure 12 shows an example of the thickness of each part on a schematic cross-sectional view of the light detection device 400 according to this embodiment, corresponding to A-A' in Figure 2.

[0069] In the example shown in this figure, the optical sensor device 100 has a thickness of 0.4 ± 0.1 mm. The signal processing circuit 210 has a thickness of 0.1 mm ± 0.01 mm. The lead frame 120 has a thickness of 0.1 mm ± 0.05 mm. The distance between the side of the signal processing circuit 210 facing the mounting substrate 410 and the first side of the optical sensor device 100 is the thickness of the optical sensor device 100 minus the thickness of the lead frame 120 and the signal processing circuit 210, which in this example is 0.2 ± 0.16 mm.

[0070] As shown in this figure, the signal processing circuit 210 can be positioned so that it is in contact with the lead frame 120, which functions as an electromagnetic shield, on the second side of the optical sensor device 100, and so that it is as close as possible to the conductive pattern 420, which also functions as a shield, on the first side of the optical sensor device 100. This allows the optical sensor device 100 to more effectively block external electromagnetic waves compared to cases where a shield is formed using a conductive cover or conductive tape.

[0071] Furthermore, as shown in this figure, the lead frame 120 may be thicker than the conductive pattern 420. Such an optical sensor device 100 can more effectively block electromagnetic noise from the light-receiving surface side of the optical sensor 200 than electromagnetic noise from the opposite side of the light-receiving surface of the optical sensor 200. As a result, the optical sensor device 100 can effectively block electromagnetic noise from the light source side of the light to be detected, enabling more accurate detection of the light to be detected.

[0072] For example, when the optical sensor device 100 is used in an NDIR (Non-Dispersive Infrared) gas sensor, an infrared light source that emits infrared light is placed on the light-receiving surface side of the optical sensor 200. The infrared light source may be driven by a pulse drive circuit that operates with a square wave. By making the lead frame 120 thicker than the conductive pattern 420, the optical sensor device 100 can more effectively block electromagnetic noise from such an infrared light source drive circuit.

[0073] Figure 13 shows a plate structure 1300 according to a fifth modification of this embodiment. At least one of the lead frame 120, conductive pattern 420, conductive pattern 720, conductive pattern 820, conductive pattern 920, or conductive pattern 1020 may be a conductive plate 1310 having a plurality of openings 1320, as shown in this figure, instead of a conductive plate without openings.

[0074] In the example shown in this figure, the multiple openings 1320 are arranged in a mesh pattern on the surface of the conductive plate 1310. In this example, the conductive plate 1310 has a structure in which 0.5600 mm square openings 1320 are arranged within a 5.6000 mm square surface, with conductive frames 0.1250 mm wide placed between adjacent openings 1320. Alternatively, the multiple openings 1320 may be arranged in a honeycomb pattern on the surface of the conductive plate 1310, randomly, or at any other arbitrary position. Furthermore, although each opening 1320 is square in this example, it may be rectangular, triangular, hexagonal, circular, or any other arbitrary shape. The area of ​​the lead frame 120 or conductive pattern 420, etc., provided with such multiple openings 1320 is represented by the total area of ​​the region within the outer shape of the conductive plate 1310 including the multiple openings 1320.

[0075] Even when the conductive plate 1310 is used as a lead frame 120 or conductive pattern 420, the optical sensor device 100 can at least partially block electromagnetic waves from the outside. The smaller the aperture ratio of the conductive plate 1310 (the ratio of the area of ​​the opening to the area of ​​the conductive plate 1310), the higher the electromagnetic wave blocking rate by the conductive plate 1310. When the conductive plate 1310 is used as a lead frame 120 or conductive pattern 420, the aperture ratio may be 90% or less, and more preferably 64% or less.

[0076] By using the conductive plate 1310 as the lead frame 120 or conductive pattern 420, the amount of conductive material used can be reduced, although the electromagnetic shielding effect is reduced. Therefore, by increasing the aperture ratio of the conductive plate 1310 within the range where the required shielding effect is obtained, it becomes possible to reduce the weight or cost of the optical sensor device 100.

[0077] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0078] It should be noted that the execution order of operations, procedures, steps, and stages in the apparatus, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before," "prior to," etc., and that these can be implemented in any order unless the output of a previous process is used in a later process. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," "next," etc. for convenience, it does not mean that it is essential to perform the operations in that order. [Explanation of Symbols]

[0079] 100 Optical Sensor Devices 110 Sensor Block 120 Lead Frames 130 terminals 140 filter blocks 200 Light Sensors 205 Aperture 210 Signal Processing Circuit 400 Light detection device 410 Mounting board 420 conductive patterns 430 conductive patterns 700 Light detection device 710 Mounting board 720 conductive patterns 730 Conductive Patterns 800 Light detection device 810 Mounting board 820 conductive patterns 830 Conductive Patterns 840 Capacitors 900 Light detection device 910 Mounting board 920 conductive patterns 1000 Light detection device 1010 Mounting board 1020 Conductive Pattern 1100 Light detection device 1110 Mounting board 1115 Cover 1120 Conductive Pattern 1130 Conductive Pattern 1300 plate structure 1310 Conductive plate 1320 Aperture

Claims

1. Implemented circuit board and The optical sensor device has a first surface on the mounting substrate side and a second surface on the opposite side from the mounting substrate, and is mounted on the mounting substrate. Equipped with, The aforementioned optical sensor device is A light sensor having a light-receiving surface on the second side, A signal processing circuit electrically connected to the first surface side of the optical sensor by wire bonding, A lead frame provided on the second side of the signal processing circuit, which shields the second side of the signal processing circuit. It has, The lead frame has an opening to expose the light-receiving surface of the optical sensor to the outside. The light sensor is positioned within the aperture. The mounting substrate has a conductive pattern formed on at least one of its surface or inner layer, which faces the signal processing circuit and shields the first side of the signal processing circuit. The lead frame is electrically connected to the conductive pattern. Light detection device.

2. The light detection device according to claim 1, wherein the signal processing circuit is arranged between the lead frame and the conductive pattern, and has a smaller area than the lead frame and the conductive pattern when viewed from the light-receiving surface side of the light sensor.

3. The light detection device according to claim 1 or 2, wherein the light sensor is of the back-surface light-receiving type and has a circuit surface on the mounting substrate side.

4. The light detection device according to any one of claims 1 to 3, wherein the light sensor is an infrared sensor.

5. The light detection device according to any one of claims 1 to 4, wherein the signal processing circuit is an integrated circuit chip having a circuit surface on the mounting substrate side.

6. The photodetector according to any one of claims 1 to 5, wherein the lead frame has a single terminal electrically connected to the conductive pattern.

7. The photodetector according to any one of claims 1 to 5, wherein the lead frame has two or more terminals electrically connected to the conductive pattern.

8. The photodetector according to any one of claims 1 to 7, wherein the conductive pattern is electrically connected to the ground of the mounting substrate.

9. The light detection device according to any one of claims 1 to 8, wherein the lead frame has a plurality of terminals provided at intervals of 2.85 mm or less on at least a portion of the edge of the light sensor device.

10. The photodetector according to any one of claims 1 to 9, wherein the conductive pattern is provided on the surface of the mounting substrate on the side of the photosensor device.

11. The photodetector according to any one of claims 1 to 10, wherein the conductive pattern is provided on at least one of the inner layers of the mounting substrate or on the surface of the mounting substrate opposite to the photosensor device.

12. The light detection device according to any one of claims 1 to 11, wherein the conductive pattern further faces the light sensor and further shields the surface on the first side of the light sensor.

13. The light detection device according to any one of claims 1 to 12, wherein the lead frame is thicker than the conductive pattern.

14. The optical sensor device has a structure in which the optical sensor, the signal processing circuit, and the lead frame are integrated by resin encapsulation, as described in any one of claims 1 to 13.

15. The photodetector according to any one of claims 1 to 14, wherein the conductive pattern has at least one terminal pattern connected to at least one terminal of the photosensor device.

16. The light detection device according to any one of claims 1 to 15, comprising a cover provided on the mounting surface side of the mounting substrate for the light sensor device and covering the light sensor device.

Images