Lid for environment sensor and environment sensor

Abstract

To provide a lid for an environment sensor which can improve the waterproofness of an environment sensor at low cost.SOLUTION: A lid 30 for an environment sensor has a lid body 31 made of metal. The lid body 31 is provided with a gas flow passage 35. The cross section of the gas flow passage 35 which is vertical to the longer direction of the gas flow passage 35 is defined by a first length L of a first direction and a second length of a second direction vertical to the first direction. The first length L is not larger than the second length and is 0.1 mm at a maximum.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a lid for an environmental sensor and an environmental sensor.

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2022-56697 (Patent Document 1) discloses a pressure sensor including a MEMS chip and a housing that houses the MEMS chip. The housing includes a lid portion. An opening is provided in the lid portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0004] An object of the present disclosure is to provide a lid for an environmental sensor that is low-cost and improves the waterproofness of the environmental sensor.

[0005] The lid for an environmental sensor of the present disclosure includes a lid body made of metal. A gas passage is provided in the lid body. A cross-section of the gas passage perpendicular to the longitudinal direction of the gas passage is defined by a first length in a first direction and a second length in a second direction perpendicular to the first direction. The first length is less than or equal to the second length and is less than or equal to 0.1 mm.

Brief Description of the Drawings

[0006]

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[0007] Details of embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated. At least a part of the configurations of the embodiments described below may be arbitrarily combined.

[0008] (Embodiment 1)

[0009] The environmental sensor 1 according to Embodiment 1 will be described with reference to FIGS. 1 and 2. The environmental sensor 1 mainly includes a case 10, an environmental sensor chip 23, and a lid 30 for the environmental sensor. The environmental sensor 1 may further include a semiconductor chip 20, bumps 21, conductive wires 26, and a sealing member 28.

[0010] The case 10 is formed of, for example, ceramic. The case 10 includes a base portion 11 and side walls 12. The case 10 may further include external connection pads 16, internal connection pads 17 and 18, and a metal layer 45.

[0011] The side wall 12 is connected to the base portion 11. The case 10 is provided with a storage space 14 and an opening 15 that communicates with the storage space 14. The storage space 14 is a space surrounded by the base portion 11 and the side wall 12. The side of the storage space 14 opposite to the base portion 11 is open.

[0012] The external connection pad 16 is disposed on the outer surface of the base portion 11. The environmental sensor 1 is electrically connected to a printed wiring board (not shown) or the like via the external connection pad 16. The internal connection pad 17 is disposed on the inner surface of the base portion 11. The internal connection pad 17 is electrically connected to the external connection pad 16 by a conductor (not shown) embedded in the base portion 11. A step 13 is formed on the inner surface of the side wall 12. The internal connection pad 18 is disposed on the step 13. The internal connection pad 18 is electrically connected to at least one of the external connection pad 16 or the internal connection pad 17 by a conductor (not shown) embedded in the case 10. The metal layer 45 is disposed at the upper end of the side wall 12.

[0013] The semiconductor chip 20 processes the signal output from the environmental sensor chip 23 and outputs a signal regarding the environment around the environmental sensor 1 to the outside of the environmental sensor 1. The semiconductor chip 20 is disposed in the storage space 14. Specifically, the semiconductor chip 20 is fixed to the internal connection pad 17 by bumps 21 and is electrically connected to the internal connection pad 17. The bumps 21 are formed of, for example, gold.

[0014] The environmental sensor chip 23 outputs a signal according to the environment around the environmental sensor 1. As an example, the environmental sensor chip 23 is a pressure sensor that measures the pressure around the environmental sensor 1, such as a MEMS (Micro Electro Mechanical System) pressure sensor, and outputs a signal related to the pressure around the environmental sensor 1. The environmental sensor chip 23 includes a detection unit 23a that detects the environment around the environmental sensor 1. The environmental sensor chip 23 is disposed within the accommodation space 14. Specifically, the environmental sensor chip 23 is fixed onto the semiconductor chip 20 using an adhesive 24.

[0015] The environmental sensor chip 23 may further include bonding pads 25. The conductive wire 26 is bonded to the bonding pads 25 and the internal connection pads 18. The conductive wire 26 is formed of, for example, gold. The environmental sensor chip 23 is electrically connected to the semiconductor chip 20 by the conductive wire 26, the internal connection pads 18, a conductor (not shown) embedded within the case 10, the internal connection pads 17, and the bumps 21.

[0016] The sealing member 28 seals the semiconductor chip 20 and the environmental sensor 1. The sealing member 28 is formed of a gel such as, for example, silicone gel.

[0017] The lid 30 for the environmental sensor covers the opening 15 of the case 10. The lid 30 for the environmental sensor and the case 10 constitute a package that houses the environmental sensor chip 23. The lid 30 for the environmental sensor includes a lid body 31. The lid body 31 is made of metal and is formed of, for example, SUS or the like. The lid body 31 is, for example, a metal plate. The lid body 31 includes a main surface 31a facing the environmental sensor chip 23 and a main surface 31b opposite to the main surface 31a. The main surfaces 31a, 31b extend in the x direction and the y direction perpendicular to the x direction, respectively. The thickness direction of the lid body 31 is the z direction perpendicular to the x direction and the y direction. The outer peripheral region of the main surface 31a is welded to the metal layer 45.

[0018] A gas passage 35 is provided in the lid body 31. The gas passage 35 communicates with the accommodation space 14 of the case 10 and the environment around the environmental sensor 1. The cross-section of the gas passage 35 perpendicular to the longitudinal direction (z-direction) of the gas passage 35 is defined by a first length L in the first direction (x-direction) and a second length in the second direction (y-direction) perpendicular to the first direction. The first length L is less than or equal to the second length and is 0.1 mm or less. The first length L is, for example, 1 μm or more. Therefore, changes in the environment around the environmental sensor 1 can be detected at an appropriate response speed using the environmental sensor chip 23.

[0019] The gas passage 35 is, for example, a through-hole 36 provided in the lid body 31 (metal plate). The longitudinal direction (z-direction) of the gas passage 35 is the thickness direction of the lid body 31 (metal plate). In the present embodiment, the cross-sectional shape of the through-hole 36 is circular, and the first length L and the second length are each the diameter of the through-hole 36 and are equal to each other. The diameter of the through-hole 36 is 0.1 mm or less. The cross-sectional shape of the through-hole 36 may be elliptical, and the first length L may be the length in the minor axis direction of the ellipse. The cross-sectional shape of the through-hole 36 may be square, and the first length L may be the length of one side of the square. The cross-sectional shape of the through-hole 36 may be rectangular, and the first length L may be the length of the short side of the rectangle. The through-hole 36 is formed by machining the lid body 31 using a drill or the like, or by etching the lid body 31.

[0020] The environmental sensor chip 23 is disposed in the accommodation space 14 of the case 10. The accommodation space 14 communicates with the environment around the environmental sensor 1 through the gas passage 35. Therefore, the environmental sensor chip 23 can measure the environment around the environmental sensor 1.

[0021] Referring to FIG. 3, the operation of this embodiment will be described. When the environmental sensor 1 is immersed in the water 50, the water 50 enters the gas passage 35. However, the first length L is 0.1 mm or less. Therefore, due to the surface tension of the water 50 in the gas passage 35, the water 50 does not enter the accommodation space 14. The lid 30 for environmental sensor improves the waterproof property of the environmental sensor 1.

[0022] Also, in the lid 30 for environmental sensor of this embodiment, the lid body 31 is made of metal, and the gas passage 35 can be formed in the lid body 31 by an inexpensive manufacturing method such as machining. Therefore, the cost of the lid 30 for environmental sensor of this embodiment can be reduced. On the other hand, in the lid for environmental sensor of the comparative example, the lid body is made of semiconductor, and the gas passage is formed in the lid body by a photolithography process. Therefore, the cost of the lid for environmental sensor of the comparative example is high.

[0023] Referring to FIGS. 4 and 5, in a modification of this embodiment, a plurality of through holes 36 may be provided in the lid body 31, and the gas passage 35 may be the plurality of through holes 36. Therefore, the volume of the gas moving between the environment around the environmental sensor 1 and the accommodation space 14 per unit time can be increased. As the environmental sensor chip 23, an environmental sensor chip with a higher response speed, such as a humidity sensor chip or a gas sensor chip, can be used. In this modification, the signal regarding the environment output from the environmental sensor chip 23 is taken out of the environmental sensor 1 through the bonding pad 25, the conductive wire 26, the internal connection pad 18, a conductor (not shown) embedded in the case 10, and the external connection pad 16.

[0024] The effects of the lid 30 for environmental sensor and the environmental sensor 1 of this embodiment will be described.

[0025] The lid 30 for the environmental sensor according to this embodiment includes a lid body 31 made of metal. A gas passage 35 is provided in the lid body 31. The cross-section of the gas passage 35 perpendicular to the longitudinal direction (z direction) of the gas passage 35 is defined by a first length L in a first direction (x direction) and a second length in a second direction (y direction) perpendicular to the first direction. The first length L is equal to or less than the second length and is equal to or less than 0.1 mm.

[0026] Therefore, due to the surface tension of the water 50 in the gas passage 35, the water 50 does not enter the accommodation space 14. The lid 30 for the environmental sensor improves the waterproof property of the environmental sensor 1. Further, since the lid body 31 is made of metal, the gas passage 35 can be formed inexpensively in the lid body 31. The cost of the lid 30 for the environmental sensor can be reduced.

[0027] In the lid 30 for the environmental sensor according to this embodiment, the lid body 31 is a metal plate. The gas passage 35 is at least one through hole 36 provided in the metal plate.

[0028] Therefore, the lid 30 for the environmental sensor improves the waterproof property of the environmental sensor 1. Further, since the lid body 31 is a metal plate, the gas passage 35 can be formed inexpensively in the lid body 31. The cost of the lid 30 for the environmental sensor can be reduced.

[0029] The environmental sensor 1 according to this embodiment includes a case 10, an environmental sensor chip 23, and a lid 30 for the environmental sensor. The case 10 is provided with an accommodation space 14 and an opening 15 communicating with the accommodation space 14. The environmental sensor chip 23 is disposed in the accommodation space 14. The lid 30 for the environmental sensor covers the opening 15. The gas passage 35 communicates with the accommodation space 14.

[0030] Since the environmental sensor 1 includes the lid 30 for the environmental sensor, the environmental sensor 1 is low-cost and has improved waterproof property.

[0031] (Embodiment 2)

[0032] Referring to FIGS. 6 and 7, the environmental sensor 1 of Embodiment 2 will be described. The environmental sensor 1 of this embodiment has the same configuration as the environmental sensor 1 of Embodiment 1 shown in FIGS. 1 and 2, but is mainly different from the environmental sensor 1 of Embodiment 1 in the following points.

[0033] The lid 30 for the environmental sensor of this embodiment further includes a water-repellent film 40. The water-repellent film 40 is formed on the gas passage 35. Specifically, the water-repellent film 40 is formed on the surface of the metal plate (lid body 31) that defines the through hole 36. The water-repellent film 40 is formed of an organosilicon compound such as tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane (C 8 H 4 Cl 3 F 13 Si), etc. The water-repellent film 40 is formed by subjecting the surface of the metal plate that defines the through hole 36 to a water-repellent treatment.

[0034] The lid 30 for the environmental sensor of this embodiment has the following effects in addition to the effects of the lid 30 for the environmental sensor of Embodiment 1.

[0035] The lid 30 for the environmental sensor of this embodiment further includes a water-repellent film 40 formed on the surface of the metal plate that defines at least one through hole 36.

[0036] As shown in FIG. 8, even when the environmental sensor 1 is immersed in water 50, the water-repellent film 40 prevents the water 50 from entering the gas passage 35 and the accommodation space 14. Therefore, the lid 30 for the environmental sensor improves the waterproof performance of the environmental sensor 1. As shown in FIG. 9, when the environmental sensor 1 is taken out of the water 50, the water-repellent film 40 prevents the water 50 from remaining in the gas passage 35 and blocking the gas passage 35. Therefore, the environmental sensor 1 can be used immediately after it is taken out of the water 50.

[0037] (Embodiment 3)

[0038] Referring to FIGS. 10 to 12, the environmental sensor 1 of Embodiment 3 will be described. The environmental sensor 1 of the present embodiment has the same configuration as the environmental sensor 1 of the modification of Embodiment 1 shown in FIGS. 4 and 5, but is mainly different from the environmental sensor 1 of the modification of Embodiment 1 in the following points.

[0039] In the present embodiment, the lid body 31 includes a first metal plate 32 and a second metal plate 33. The first metal plate 32 and the second metal plate 33 are formed of, for example, SUS or the like.

[0040] The first metal plate 32 is disposed closer to the environmental sensor chip 23 and the case 10 than the second metal plate 33. The first metal plate 32 includes a main surface 32a facing the environmental sensor 1, a main surface 32b opposite to the main surface 32a, and a side surface 32s. The main surfaces 32a and 32b extend in the x direction and the y direction perpendicular to the x direction, respectively. The thickness direction of the first metal plate 32 is the z direction perpendicular to the x direction and the y direction. The side surface 32s is connected to the main surface 32a and the main surface 32b. The side surface 32s extends in the y direction and the z direction. The outer peripheral region of the main surface 32a is welded to the metal layer 45.

[0041] A through hole 37 is provided in the main surface 32b. The through hole 37 extends from the main surface 32a to the main surface 32b. The diameter d of the through hole 37 is larger than the first length L of the gas passage 35. The diameter d of the through hole 37 is larger than 0.1 mm. The diameter d of the through hole 37 may be 0.2 mm or more, or may be 0.5 mm or more. The through hole 37 is formed, for example, by electrical discharge machining of the first metal plate 32 or by machining the first metal plate 32 using a drill or the like.

[0042] The second metal plate 33 is stacked on the first metal plate 32. The second metal plate 33 includes a main surface 33a facing the main surface 32b and a side surface 33s connected to the main surface 33a. The main surface 33a extends in the x direction and the y direction. The thickness direction of the second metal plate 33 is the z direction. The side surface 33s is connected to the main surface 33a. The side surface 33s extends in the y direction and the z direction.

[0043] A recess 38 is formed in the main surface 33a. The recess 38 has a width w (see FIG. 10) and a depth. The depth of the recess 38 is smaller than the width w of the recess 38. The recess 38 is formed, for example, by electrical discharge machining the second metal plate 33 or by machining the second metal plate 33 using a drill or the like. The recess 38 is connected to the side surface 33s.

[0044] The gas passage 35 is formed by stacking the first metal plate 32 and the second metal plate 33 in which the recess 38 is formed. That is, the gas passage 35 is formed between the main surface 32b and the main surface 33a by the recess 38. The recess 38 communicates with the through hole 37.

[0045] The cross-section of the gas passage 35 perpendicular to the longitudinal direction (y direction) of the gas passage 35 is defined by a first length L in a first direction (z direction) and a second length in a second direction (y direction) perpendicular to the first direction. The first length L is smaller than the second length and is 0.1 mm or less. In the present embodiment, the first length L of the gas passage 35 is the depth of the recess 38. The second length of the gas passage 35 is the width w of the recess 38. When the depth of the recess 38 changes, the first length L is the maximum depth of the recess 38. The depth of the recess 38 is 0.1 mm or less. The width w of the recess 38 is greater than 0.1 mm. The width w of the recess 38 may be 0.2 mm or more, or may be 0.5 mm or more.

[0046] The environmental sensor chip 23 is disposed in the accommodation space 14 of the case 10. The accommodation space 14 communicates with the environment around the environmental sensor 1 through the gas passage 35 and the through hole 37. Therefore, the environmental sensor chip 23 can measure the environment around the environmental sensor 1.

[0047] Referring to FIG. 13, the operation of the present embodiment will be described. When the environmental sensor 1 is immersed in water 50, the water 50 enters the gas passage 35. However, the first length L (depth of the recess 38) is 0.1 mm or less. Therefore, due to the surface tension of the water 50 in the gas passage 35, the water 50 does not enter the through hole 37 and the accommodation space 14. The lid 30 for the environmental sensor improves the waterproof property of the environmental sensor 1. Further, since the lid body 31 is made of metal, the gas passage 35 can be formed in the lid body 31 by an inexpensive manufacturing method such as machining. Therefore, the cost of the lid 30 for the environmental sensor can be reduced.

[0048] Referring to FIGS. 14 and 15, in a modification of the present embodiment, the recess 38 is formed in the main surface 32b and is connected to the side surface 32s. The recess 38 may be formed in both the main surface 32a and the main surface 32b, and may be connected to the side surfaces 32s, 33s.

[0049] Referring to FIG. 16, in another modification of the present embodiment, the lid 30 for the environmental sensor may further include a water-repellent film 40. The water-repellent film 40 is formed on the gas passage 35. Specifically, the water-repellent film 40 is formed on the recess 38. For example, in a plan view of the main surface 32b, the water-repellent film 40 extends at least from the side surface (side surface 32s or side surface 33s) of the lid body 31 to the through hole 37.

[0050] The lid 30 for the environmental sensor of the present embodiment exhibits the following effects similar to those of the lid 30 for the environmental sensor of Embodiment 1.

[0051] In the lid 30 for an environmental sensor according to this embodiment, the lid body 31 includes a first metal plate 32 and a second metal plate 33 stacked on the first metal plate 32. The first metal plate 32 includes a first main surface (main surface 32b) and a first side surface (side surface 32s) connected to the first main surface. The second metal plate 33 includes a second main surface (main surface 33a) facing the first main surface and a second side surface (side surface 33s) connected to the second main surface. A through hole 37 is provided in the first main surface. A recess 38 is formed in at least one of the first main surface and the second main surface. The recess 38 forms a gas passage 35 between the first main surface and the second main surface. The gas passage 35 communicates with the through hole 37 and is connected to at least one of the first side surface and the second side surface.

[0052] The first length L (depth of the recess 38) is 0.1 mm or less. Therefore, due to the surface tension of the water 50 in the gas passage 35, the water 50 does not penetrate into the through hole 37 and the accommodation space 14. The lid 30 for an environmental sensor improves the waterproof property of the environmental sensor 1. Further, since the lid body 31 is made of metal, the gas passage 35 can be inexpensively formed in the lid body 31. The cost of the lid 30 for an environmental sensor can be reduced.

[0053] The lid 30 for an environmental sensor according to this embodiment further includes a water-repellent film 40 formed on the recess 38.

[0054] Even when the environmental sensor 1 is immersed in the water 50, the water-repellent film 40 prevents the water 50 from penetrating into the gas passage 35, the through hole 37, and the accommodation space 14. Therefore, the lid 30 for an environmental sensor improves the waterproof property of the environmental sensor 1. Further, when the environmental sensor 1 is taken out of the water 50, the water-repellent film 40 prevents the water 50 from remaining in the gas passage 35 and blocking the gas passage 35. Therefore, the environmental sensor 1 can be used immediately after being taken out of the water 50.

[0055] (Embodiment 4)

[0056] Referring to FIGS. 17 and 18, the environmental sensor 1 of Embodiment 4 will be described. The environmental sensor 1 of the present embodiment has the same configuration as the environmental sensor 1 of Embodiment 3 shown in FIGS. 10 to 12, but is mainly different from the environmental sensor 1 of Embodiment 3 in the following points.

[0057] In the lid 30 for the environmental sensor of the present embodiment, a rough surface 39 is formed on the main surface 33a instead of the concave portion 38 (see FIGS. 10 to 12). The rough surface 39 is formed, for example, by sandblasting the main surface 33a. The rough surface 39 is connected to the side surface 33s.

[0058] The gas passage 35 is formed by stacking the first metal plate 32 and the second metal plate 33 having the rough surface 39 formed thereon. That is, the gas passage 35 is formed between the main surface 32b and the main surface 33a by the rough surface 39. The gas passage 35 communicates with the through hole 37.

[0059] The cross-section of the gas passage 35 perpendicular to the longitudinal direction (y direction) of the gas passage 35 is defined by a first length L in a first direction (z direction) and a second length in a second direction (x direction) perpendicular to the first direction. The first length L is smaller than the second length and is 0.1 mm or less. In the present embodiment, the first length L of the gas passage 35 is the surface roughness of the rough surface 39. The surface roughness of the rough surface 39 is 0.1 mm or less. In this specification, the surface roughness is the maximum height Rz defined by Japanese Industrial Standard (JIS) B 0601:2013. The second length of the gas passage 35 is the length in the second direction (y direction) of the region of the second metal plate 33 where the rough surface 39 is formed. The second length is greater than 0.1 mm. The second length may be 0.2 mm or more, or may be 0.5 mm or more.

[0060] The operation of this embodiment will be described. When the environmental sensor 1 is immersed in the water 50, the water 50 enters the gas passage 35. However, the first length L (the surface roughness of the rough surface 39) is 0.1 mm or less. Therefore, due to the surface tension of the water 50 in the gas passage 35, the water 50 does not enter the through hole 37 and the accommodation space 14. The lid 30 for the environmental sensor improves the waterproof property of the environmental sensor 1. Further, since the lid body 31 is made of metal, the gas passage 35 can be formed in the lid body 31 by an inexpensive manufacturing method such as machining. Therefore, the cost of the lid 30 for the environmental sensor can be reduced.

[0061] Referring to FIG. 19, in a modification of this embodiment, the rough surface 39 is formed on the main surface 32b and is connected to the side surface 32s. The rough surface 39 may be formed on both the main surface 32a and the main surface 32b, and may be connected to the side surfaces 32s and 33s.

[0062] Referring to FIG. 20, in another modification of this embodiment, the lid 30 for the environmental sensor may further include a water-repellent film 40. The water-repellent film 40 is formed on the gas passage 35. Specifically, the water-repellent film 40 is formed on the rough surface 39. For example, in a plan view of the main surface 32b, the water-repellent film 40 extends at least from the side surface (side surface 32s or side surface 33s) of the lid body 31 to the through hole 37.

[0063] The lid 30 for the environmental sensor of this embodiment has the following effects similar to those of the lid 30 for the environmental sensor of Embodiment 3.

[0064] In the lid 30 for an environmental sensor according to this embodiment, the lid body 31 includes a first metal plate 32 and a second metal plate 33 stacked on the first metal plate 32. The first metal plate 32 includes a first main surface (main surface 32b) and a first side surface (side surface 32s) connected to the first main surface. The second metal plate 33 includes a second main surface (main surface 33a) facing the first main surface and a second side surface (side surface 33s) connected to the second main surface. A through hole 37 is provided in the first main surface. A rough surface 39 is formed on at least one of the first main surface and the second main surface. A gas passage 35 is formed between the first main surface and the second main surface by the rough surface 39. The gas passage 35 communicates with the through hole 37 and is connected to at least one of the first side surface and the second side surface.

[0065] The first length L (surface roughness of the rough surface 39) is 0.1 mm or less. Therefore, due to the surface tension of the water 50 in the gas passage 35, the water 50 does not enter the through hole 37 and the accommodation space 14. The lid 30 for an environmental sensor improves the waterproof property of the environmental sensor 1. Also, since the lid body 31 is made of metal, the gas passage 35 can be inexpensively formed in the lid body 31. The cost of the lid 30 for an environmental sensor can be reduced.

[0066] The lid 30 for an environmental sensor according to this embodiment may further include a water-repellent film 40 formed on the rough surface 39.

[0067] Even when the environmental sensor 1 is immersed in the water 50, the water-repellent film 40 prevents the water 50 from entering the gas passage 35, the through hole 37, and the accommodation space 14. Therefore, the lid 30 for an environmental sensor improves the waterproof property of the environmental sensor 1. Also, when the environmental sensor 1 is taken out of the water 50, the water-repellent film 40 prevents the water 50 from remaining in the gas passage 35 and blocking the gas passage 35. Therefore, the environmental sensor 1 can be used immediately after being taken out of the water 50.

[0068] (Embodiment 5)

[0069] Referring to FIGS. 21 to 23, the environmental sensor 1 of Embodiment 5 will be described. The environmental sensor 1 of the present embodiment has the same configuration as the environmental sensor 1 of Embodiment 1, but mainly differs from the environmental sensor 1 of Embodiment 1 in the following points.

[0070] The environmental sensor 1 of the present embodiment includes an environmental sensor chip 23 and an environmental sensor lid 30. The environmental sensor 1 may further include conductive wires 26 and sealing members 48 and 49.

[0071] The environmental sensor lid 30 is stacked on the environmental sensor chip 23 and covers the detection unit 23a. The environmental sensor lid 30 provides a chip size package (CSP) for the environmental sensor chip 23.

[0072] The environmental sensor lid 30 includes a lid body 31. The lid body 31 is made of metal, for example, formed of SUS. The lid body 31 is, for example, a metal plate. The lid body 31 includes a main surface 31a facing the environmental sensor chip 23 and a side surface 31s connected to the main surface 31a. A rough surface 39 is formed on the main surface 31a. The rough surface 39 of the present embodiment is the same as the rough surface 39 of Embodiment 4. The rough surface 39 is connected to the side surface 31s.

[0073] The gas passage 35 is formed by stacking the environmental sensor chip 23 and the environmental sensor lid 30 on which the rough surface 39 is formed. The rough surface 39 forms the gas passage 35 between the environmental sensor chip 23 and the main surface 31a. The gas passage 35 communicates with the detection unit 23a and is connected to the side surface 31s.

[0074] The cross-section of the gas passage 35 perpendicular to the longitudinal direction (y direction) of the gas passage 35 is defined by a first length L in a first direction (z direction) and a second length in a second direction (x direction) perpendicular to the first direction. The first length L is smaller than the second length and is 0.1 mm or less. In the present embodiment, the first length L of the gas passage 35 is the surface roughness of the rough surface 39. The surface roughness of the rough surface 39 is 0.1 mm or less. The surface roughness is the maximum height Rz defined by Japanese Industrial Standard (JIS) B 0601:2013. The second length of the gas passage 35 is, for example, the distance between the sealing member 48 and the sealing member 49 in the second direction. The second length is greater than 0.1 mm. The second length may be 0.2 mm or more, or may be 0.5 mm or more.

[0075] The environmental sensor chip 23 may include bonding pads 25. The bonding pads 25 are disposed on the surface of the environmental sensor chip 23 exposed from the environmental sensor lid 30. The conductive wire 26 is bonded to the bonding pad 25. A signal regarding the environment output from the environmental sensor chip 23 is taken out of the environmental sensor 1 through the bonding pad 25 and the conductive wire 26.

[0076] The sealing members 48 and 49 seal the connection portion between the bonding pad 25 and the conductive wire 26. The sealing members 48 and 49 are, for example, epoxy resins. The sealing members 48 and 49 may also be formed on the environmental sensor lid 30, and the environmental sensor lid 30 may be fixed to the environmental sensor chip 23. The sealing members 48 and 49 may be formed between the environmental sensor chip 23 and the main surface 31a.

[0077] The operation of this embodiment will be described. When the environmental sensor 1 is immersed in the water 50, the water 50 enters the gas passage 35. However, the first length L (the surface roughness of the rough surface 39) is 0.1 mm or less. Therefore, due to the surface tension of the water 50 in the gas passage 35, the water 50 does not enter the detection unit 23a. The lid 30 for the environmental sensor improves the waterproof property of the environmental sensor 1. Further, since the lid body 31 is made of metal, the gas passage 35 can be formed in the lid body 31 by an inexpensive manufacturing method such as machining. Therefore, the cost of the lid 30 for the environmental sensor can be reduced.

[0078] Referring to FIG. 24, in a modification of this embodiment, a recess 38 is formed on the main surface 31a instead of the rough surface 39. The recess 38 of this embodiment is the same as the recess 38 of Embodiment 3. The recess 38 is connected to the side surface 31s. The gas passage 35 is formed by stacking the first metal plate 32 and the second metal plate 33 in which the recess 38 is formed. That is, the gas passage 35 is formed between the environmental sensor chip 23 and the main surface 31a by the recess 38. The recess 38 communicates with the detection unit 23a.

[0079] The cross-section of the gas passage 35 perpendicular to the longitudinal direction (y direction) of the gas passage 35 is defined by the first length L in the first direction (z direction) and the second length in the second direction (x direction) perpendicular to the first direction. The first length L is smaller than the second length and is 0.1 mm or less. In the modification of this embodiment, the first length L of the gas passage 35 is the depth of the recess 38. The second length of the gas passage 35 is the width w of the recess 38. When the depth of the recess 38 changes, the first length L is the maximum depth of the recess 38. The depth (first length L) of the recess 38 is 0.1 mm or less. The width w of the recess 38 is larger than 0.1 mm. The width w of the recess 38 may be 0.2 mm or more, or may be 0.5 mm or more.

[0080] As shown in FIGS. 25 and 26, in another modification of the present embodiment, the lid 30 for the environmental sensor may include a water-repellent film 40. The water-repellent film 40 is formed on the gas passage 35. Specifically, as shown in FIG. 25, the water-repellent film 40 may be formed on the rough surface 39. As shown in FIG. 26, the water-repellent film 40 may be formed on the concave portion 38. For example, in a plan view of the main surface 31a, the water-repellent film 40 extends at least from the side surface 31s to the detection portion 23a.

[0081] In addition to the effects of the environmental sensor 1 of the first embodiment, the environmental sensor 1 of the present embodiment has the following effects.

[0082] The environmental sensor 1 of the present embodiment includes an environmental sensor chip 23 and a lid 30 for the environmental sensor. The environmental sensor chip 23 includes a detection portion 23a. The lid 30 for the environmental sensor is stacked on the environmental sensor chip 23 and covers the detection portion 23a. The lid 30 for the environmental sensor includes a lid body 31 made of metal. The lid body 31 includes a main surface 31a facing the environmental sensor chip 23 and a side surface 31s connected to the main surface 31a. A concave portion 38 or a rough surface 39 is formed on the main surface 31a. The gas passage 35 is formed between the environmental sensor chip 23 and the main surface 31a by the concave portion 38 or the rough surface 39. The gas passage 35 communicates with the detection portion 23a and is connected to the side surface 31s. The depth of the concave portion 38 or the surface roughness of the rough surface 39 is 0.1 mm or less.

[0083] The depth of the concave portion 38 or the surface roughness of the rough surface 39 is 0.1 mm or less. Therefore, due to the surface tension of the water 50 in the gas passage 35, the water 50 does not enter the detection portion 23a. The lid 30 for the environmental sensor improves the waterproof property of the environmental sensor 1. Further, since the lid body 31 is made of metal, the gas passage 35 can be inexpensively formed in the lid body 31. The cost of the environmental sensor 1 can be reduced. Further, since a chip size package becomes possible, the environmental sensor 1 can be miniaturized.

[0084] The lid 30 for the environmental sensor according to this embodiment includes a water-repellent film 40 formed on the concave portion 38 or the rough surface 39.

[0085] Even when the environmental sensor 1 is immersed in water 50, the water-repellent film 40 prevents the water 50 from entering the gas passage 35 and the detection unit 23a. Therefore, the lid 30 for the environmental sensor improves the waterproof property of the environmental sensor 1. Further, when the environmental sensor 1 is taken out of the water 50, the water-repellent film 40 prevents the water 50 from remaining in the gas passage 35 and blocking the gas passage 35. Therefore, the environmental sensor 1 can be used immediately after being taken out of the water 50.

[0086] Hereinafter, aspects of the present disclosure will be collectively described as appendices. (Appendix 1) Comprising a lid body made of metal, A gas passage is provided in the lid body, The cross-section of the gas passage perpendicular to the longitudinal direction of the gas passage is defined by a first length in a first direction and a second length in a second direction perpendicular to the first direction, The first length is less than or equal to the second length and is 0.1 mm or less, a lid for an environmental sensor. (Appendix 2) The lid body is a metal plate, The gas passage is at least one through-hole provided in the metal plate, the lid for an environmental sensor according to Appendix 1. (Appendix 3) Further comprising a water-repellent film formed on the surface of the metal plate defining the at least one through-hole, the lid for an environmental sensor according to Appendix 2. (Appendix 4) The lid body includes a first metal plate and a second metal plate stacked on the first metal plate, The first metal plate includes a first main surface and a first side surface connected to the first main surface, The second metal plate includes a second main surface facing the first main surface and a second side surface connected to the second main surface, A through-hole is provided in the first main surface, At least one of the first main surface or the second main surface is formed with a concave portion or a rough surface, The gas passage is formed between the first main surface and the second main surface by the concave portion or the rough surface, The gas passage according to Appendix 1, which communicates with the through hole and is connected to at least one of the first side surface or the second side surface. (Appendix 5) The lid for an environmental sensor according to Appendix 4, further comprising a water-repellent film formed on the concave portion or the rough surface. (Appendix 6) A case, An environmental sensor chip, And the lid for an environmental sensor according to any one of Appendices 1 to 5, The case is provided with a housing space and an opening communicating with the housing space, The environmental sensor chip is disposed in the housing space, The lid for an environmental sensor covers the opening, The environmental sensor, wherein the gas passage communicates with the housing space. (Appendix 7) An environmental sensor chip including a detection unit, And a lid for an environmental sensor stacked on the environmental sensor chip and covering the detection unit, The lid for an environmental sensor includes a lid body made of metal, The lid body includes a main surface facing the environmental sensor chip and a side surface connected to the main surface, A concave portion or a rough surface is formed on the main surface, A gas passage is formed between the environmental sensor chip and the main surface by the concave portion or the rough surface, The gas passage communicates with the detection unit and is connected to the side surface, The environmental sensor, wherein the depth of the concave portion or the surface roughness of the rough surface is 0.1 mm or less. (Appendix 8) The environmental sensor lid is the environmental sensor according to Supplementary Note 7, including a water-repellent film formed on the concave portion or the rough surface.

[0087] The embodiments 1-5 and their modified examples disclosed this time should be considered illustrative in all respects and not restrictive. As long as there is no contradiction, at least two of the embodiments 1-5 and their modified examples disclosed this time may be combined. The scope of the present disclosure is indicated by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

Explanation of Reference Numerals

[0088] 1 Environmental sensor, 10 Case, 11 Base portion, 12 Side wall, 13 Step, 14 Accommodation space, 15 Opening, 16 External connection pad, 17, 18 Internal connection pad, 20 Semiconductor chip, 21 Bump, 23 Environmental sensor chip, 23a Detection portion, 24 Adhesive, 25 Bonding pad, 26 Conductive wire, 28 Sealing member, 30 Environmental sensor lid, 31 Lid body, 31a, 31b Main surface, 32 First metal plate, 32a, 32b Main surface, 32s Side surface, 33 Second metal plate, 33a Main surface, 33s Side surface, 35 Gas passage, 36, 37 Through hole, 38 Concave portion, 39 Rough surface, 40 Water-repellent film, 45 Metal layer, 48, 49 Sealing member, 50 Water.

Claims

1. Comprising a metal lid body, a gas passage is provided in the lid body, the cross-section of the gas passage perpendicular to the longitudinal direction of the gas passage is defined by a first length in a first direction and a second length in a second direction perpendicular to the first direction, the first length is less than or equal to the second length and is less than or equal to 0.1 mm, a lid for an environmental sensor.

2. The lid body is a metal plate, the gas passage is at least one through-hole provided in the metal plate, the lid for an environmental sensor according to claim 1.

3. Further comprising a water-repellent film formed on the surface of the metal plate defining the at least one through-hole, the lid for an environmental sensor according to claim 2.

4. The lid body includes a first metal plate and a second metal plate stacked on the first metal plate, the first metal plate includes a first main surface and a first side surface connected to the first main surface, the second metal plate includes a second main surface facing the first main surface and a second side surface connected to the second main surface, a through-hole is provided in the first main surface, at least one of the first main surface or the second main surface is formed with a recess or a rough surface, the gas passage is formed between the first main surface and the second main surface by the recess or the rough surface, the gas passage communicates with the through-hole and is connected to at least one of the first side surface or the second side surface, the lid for an environmental sensor according to claim 1.

5. Further comprising a water-repellent film formed on the recess or the rough surface, the lid for an environmental sensor according to claim 4.

6. A case, an environmental sensor chip, and the lid for an environmental sensor according to any one of claims 1 to 5, the case is provided with a housing space and an opening communicating with the housing space, the environmental sensor chip is disposed in the housing space, the lid for an environmental sensor covers the opening, the gas passage communicates with the housing space, an environmental sensor.

7. An environmental sensor chip including a detection unit, and a lid for an environmental sensor stacked on the environmental sensor chip and covering the detection unit, the lid for an environmental sensor includes a metal lid body, the lid body includes a main surface facing the environmental sensor chip and a side surface connected to the main surface, The main surface is formed with a concave portion or a rough surface, and a gas passage is formed between the environmental sensor chip and the main surface by the concave portion or the rough surface, the gas passage communicates with the detection portion and is connected to the side surface, and the depth of the concave portion or the surface roughness of the rough surface is 0.1 mm or less. An environmental sensor.

8. The environmental sensor lid according to claim 7, comprising a water-repellent film formed on the concave portion or the rough surface.

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