The present invention relates to a gas sensor, in particular to a gas sensor for a handheld device.
Gas sensors are widely used to detect physical properties or chemical properties of gases, and are applied in medical, industrial, environmental protection and other fields.
The related art, such as “portable asthma detection device and stand-alone portable asthma detection device” as mentioned in the Taiwan Publication No. 201219010, relates to a gas sensor which is designed to be applicable in a manner of being externally attached to a handheld device. The gas sensor comprises a housing, a gas detection module including a turbine and a mini airflow sensing component; a gas introducing tube; and a signal delivery unit. In this way, respiratory detection can be performed anytime and anywhere, and the effect of improving the efficiency of monitoring and managing asthma can be achieved.
According to this method, it is possible to detect the gas by the handheld device, however, it is inconvenient and unfavorable to attach the gas sensor to the handheld device.
To fulfill said objective, the present invention provides a gas sensor for a handheld device and assembled in a cavity of the handheld device. The gas sensor comprises the following components: a circuit board having at least one through hole; a sensing chip disposed on the circuit board, the sensing chip having at least one sensing region exposed by the through hole; and a gas channel allowing a to-be-sensed gas to enter the through hole and to contact with the sensing region; the gas channel comprises a first sub-channel adjacent to the through hole, a second sub-channel away from the through hole, and a connection channel connecting the first sub-channel and the second sub-channel; wherein the to-be-sensed gas has a first gas pressure P1 while flowing in the first sub-channel and has a second gas pressure P2 while flowing in the second sub-channel, and the gas channel further has a structure that makes P1 lower than P2.
According to the gas sensor for the handheld device, the first sub-channel has a width D1, the second sub-channel has a width D2, and D1 is less than D2.
According to the gas sensor for the handheld device, the connection channel has an included angle.
According to the gas sensor for the handheld device, the connection channel further comprises a stopper.
According to the gas sensor for the handheld device, a wall of the connection channel further comprises a pressure relief hole.
According to the gas sensor for the handheld device, the sensing region comprises at least two sensing components for detecting different target molecules.
According to the gas sensor for the handheld device, the circuit board is a printed circuit board.
According to the gas sensor for the handheld device, the sensing chip is a flip chip.
The gas sensor for the handheld device further comprises a waterproof breathable membrane disposed between the sensing region and the gas channel.
The gas sensor for the handheld device further comprises a barrier layer which covers one side of the sensing chip and the circuit board opposite to the waterproof breathable membrane.
In summary, the present invention has the following features compared with the prior art:
1. the gas sensor is integrated in the handheld device, particularly in the cavity of the handheld device, e.g., in a cavity capable of accommodating a microphone, but is not limited thereto. The gas sensor can be integrated not only with the existing process of the handheld device but also conveniently for the user to use, without the need to carry other sensors additionally as in the prior art.
2. Through the design of the gas channel, the present invention reduces the gas pressure during blowing without damaging the sensing chip.
3. In an embodiment of the present invention, the gas sensor is provided with the waterproof breathable membrane to block moisture, dust and other tiny substances, so as not to damage the handheld device, and so as to prevent the sensing chip from being inaccurate due to moisture disturbance.
The detailed description and technical content related to the present invention will now be described as follows:
Referring to
Referring to
The sensing chip 20 has a sensing surface 21 on which at least one bonding region 212 and at least one sensing region 211 which is in contact with a to-be-sensed gas G are formed. In an embodiment, the sensing region 211 is formed by a sensing film which is fabricated using an ultra-low concentration sensing film coating technology. In an embodiment, the sensing chip 20 may be a flip chip.
The gas channel 30 is communicated with the sensing region 211 via the through hole 13. The gas channel 30 comprises a first sub-channel 31 adjacent to the through hole 13, a second sub-channel 32 away from the through hole 13, and a connection channel 33 connecting the first sub-channel 31 and the second sub-channel 32. The to-be-sensed gas G has a first gas pressure P1 while flowing in the first sub-channel 31 and has a second gas pressure P2 while flowing in the second sub-channel 32, and the gas channel 30 further has a structure that makes the first gas P1 lower than the second gas pressure P2. In this embodiment, this structure is a right-angle bend by which the to-be-sensed gas G is first blocked by the wall at the connection channel 33 after entering the gas channel 30 and moves upward, and finally passes through the waterproof breathable membrane 40 and reaches the sensing region 211. As such, the first gas pressure P1 is lower than the second gas pressure P2. Therefore, the structure of the sensing region 211 is prevented from being damaged by the stress of the waterproof breathable membrane 40 after repeated use. In other embodiments, the first sub-channel 31 has a width D1, the second sub-channel 32 has a width D2, and D1 is less than D2, e.g., D2=2D1.
In other embodiments of the present invention, the gas sensor further comprises a barrier layer 50 which covers one side of the sensing chip 20 and the circuit board 10 opposite to the waterproof breathable membrane 40. The barrier layer 50 isolates the sensing chip 20 and the circuit board 10 from the handheld device M to prevent a signal of the sensing chip 20 from interfering with the handheld device M so as not to affect the use of the handheld device M.
Referring to
Alternatively, in the third embodiment as shown in
Based on the above structure, the to-be-sensed gas G will pass through the gas channel 30 along a direction of the gas channel 30 (as indicated by the arrow) during the operation, and finally pass through the through hole 13 to reach a position of the sensing chip 20, thereby the composition of the to-be-sensed gas G can be sensed.
Referring to
In summary, the gas sensor for the handheld device M is built in the handheld device M, which is different from the prior art in which the sensor is externally attached to the handheld device M, such that the convenience, stability and dexterity can be improved. Therefore, the gas sensor of the present invention is expected to be widely used by the public.
Number | Date | Country | Kind |
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107207475 | Jun 2018 | TW | national |