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JP-7855377-B2 - Gas detection device

JP7855377B2JP 7855377 B2JP7855377 B2JP 7855377B2JP-7855377-B2

Inventors

  • 古屋 貴明
  • 一色 翔太

Assignees

  • 旭化成エレクトロニクス株式会社

Dates

Publication Date
20260508
Application Date
20220322
Priority Date
20210329

Claims (12)

  1. A light-emitting unit that emits light in a wavelength band that includes the wavelength absorbed by the detected gas, A light-receiving unit having sensitivity in the aforementioned wavelength band, A package containing the light-emitting unit and the light-receiving unit, A light guide unit that guides the aforementioned light to the light receiving unit, A joint that joins the package and the light guide portion, A thermal insulating portion provided on the surface of the package and in the gap between the package and the light guide portion, Equipped with, A portion of the surface of the package facing the light guide portion has a proximity region where the distance between the package and the light guide portion is 500 μm or less. A gas detection device is provided adjacent to a portion of the adjacent region, with at least a part of the thermal insulation portion and at least a part of the joint portion.
  2. The thermal insulation portion has a thermal conductivity of 0.1 W/m·K or less. The gas detection device according to claim 1.
  3. The thermal insulation portion has a thickness of 2 μm or more and 500 μm or less. The gas detection device according to claim 1 or 2.
  4. The coverage ratio, which is the ratio of the area of the thermal insulating part covering the adjacent region to the area of the adjacent region, is 30% or more. The gas detection device according to claim 1.
  5. The aforementioned package has a metal component content of 25% or more. A gas detection device according to any one of claims 1 to 4.
  6. The package has a protrusion that contacts the light guide portion, A gas detection device according to any one of claims 1 to 5.
  7. The light guide portion has a protrusion that contacts the package. A gas detection device according to any one of claims 1 to 5.
  8. The aforementioned thermal insulation part is a gas. A gas detection device according to any one of claims 1 to 7.
  9. The system further comprises a control unit that controls the light-emitting unit and the light-receiving unit, The package contains the control unit, A gas detection device according to any one of claims 1 to 8.
  10. The thermal conductivity of the thermal insulation portion is lower than that of the joint portion. A gas detection device according to any one of claims 1 to 9.
  11. The light guide unit has a gas port for introducing the gas to be detected. A gas detection device according to any one of claims 1 to 10.
  12. The thermal insulation portion is arranged around the light-emitting portion and the light-receiving portion. A gas detection device according to any one of claims 1 to 11.

Description

This invention relates to a gas detection device. Conventionally, gas detection devices have been used in various fields. For example, a gas detection device is known in which a light-emitting unit that emits infrared radiation and a detector that detects infrared radiation of a specific wavelength are arranged inside a case having an ellipsoidal mirror to detect the gas to be detected (see, for example, Patent Document 1). In recent years, gas detection devices have become smaller and thinner due to increasing demand for integration into portable devices such as smartphones (see, for example, Patent Document 2). Electronic components mounted in portable devices are extremely densely packed, resulting in high heat density. Furthermore, the device casings are highly airtight for waterproofing purposes, leading to heat buildup. Additionally, heat generated by heat sources such as power supplies, cameras, and computing devices in portable devices primarily diffuses to the surrounding environment via the circuit board. U.S. Patent Application Publication No. 2018/0348121U.S. Patent No. 9955244 This is a schematic cross-sectional view showing an example of the configuration of a gas detection device according to one embodiment of the present invention.This is a perspective view showing an example of the configuration of a gas detection device according to one embodiment of the present invention.This is a plan view showing an example of the configuration of a gas detection device according to one embodiment of the present invention.This is a schematic cross-sectional view showing an example of the configuration of a gas detection device according to a modified example.This is a schematic cross-sectional view showing an example of the configuration of a conventional gas detection device. The following describes in detail one embodiment of the present invention with reference to the drawings. In principle, identical components are given the same reference numeral, and redundant explanations are omitted. For the sake of clarity, the aspect ratios of each component in the drawings are exaggerated from their actual proportions. Furthermore, for the sake of clarity in the following explanation, "upper" will refer to the light guide side as depicted in the drawing, and "lower" will refer to the substrate side as depicted in the drawing. However, "upper" and "lower" are merely terms defined for convenience and should not be interpreted restrictively. <Gas detection device> An example of the configuration of the gas detection device 1 according to this embodiment will be described with reference to Figures 1, 2A, and 2B. The gas detection device 1 is mounted on a substrate 100 and is an NDIR (Non-Dispersive Infrared) type device that detects the concentration of a gas based on the amount of infrared radiation absorbed by the introduced gas. The gas detection device 1 is a small device, for example, measuring 7 mm (length) x 5 mm (width) x 3 mm (height). Examples of gases to be detected include carbon dioxide, methane, water vapor, propane, formaldehyde, carbon monoxide, nitric oxide, ammonia, sulfur dioxide, and alcohol. The gas detection device 1 comprises a light-emitting unit 10, a light-receiving unit 20, a control unit 30, a package 40, a light-guiding unit 50, a connecting unit 60, and a thermal insulation unit 70. [Light-emitting part] The light-emitting unit 10 emits light in a wavelength band that includes the wavelength absorbed by the detected gas, in accordance with the drive current or drive voltage supplied from the control unit 30. For example, the light-emitting unit 10 emits light in a wavelength band of 2.0 μm or more and 12.0 μm or less. The light-emitting unit 10 may be, for example, an LED (Light Emitting Diode), a lamp, a laser (light amplification by stimulated emission of radiation), an organic light-emitting element, a MEMS (Micro Electro Mechanical Systems) heater, or a VCSEL (Vertical Cavity Surface Emitting Laser). The light-emitting unit 10 is enclosed within the package 40. In the gas detection device 1, a thermal insulation unit 70a is provided in the gap S1 between the package 40 and the light guide unit 50, resulting in high thermal insulation between the package 40 and the light guide unit 50. Therefore, even if a heat flow enters the gas detection device 1, the heat flow is less likely to flow into the light guide unit 50, causing the temperature inside the package 40 to quickly become uniform, and the temperature of the light-emitting unit 10 enclosed within the package 40 to quickly stabilize. The light-emitting section 10 may have its upper surface in contact with the thermal insulation section 70b. By providing the thermal insulation section 70b on the upper surface of the light-emitting section 10, the temperature of the light-emitting section 10 can be further stabilized. The light-emitting unit 10 is preferably enclosed within the package 40, but it may be provided outside the pac