Gas sensing device

Abstract

The utility model provides a gas sensing device, and relates to a gas monitoring technology, the gas sensing device comprises a packaging main body and a gas sensing chip; the packaging main body comprises a base part and a peripheral part connected to the base part, a cavity located in the packaging main body is defined between the peripheral part and the base part, a cavity opening for gas to enter and exit is formed in the side, opposite to the base part, of the cavity, and the base part is provided with a circuit pattern and a plurality of airflow holes which penetrate through the base part and are communicated with the cavity; the gas sensing chip is located in the cavity, is arranged on the base part and is electrically connected with the circuit pattern. According to the gas sensing device provided by the invention, the circulation of the gas in the cavity can be increased, so that the gas is in full contact with the gas sensing chip, and the sensing precision and the sensing efficiency of the gas sensing chip on the gas are further improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gas monitoring, and more particularly to a gas sensing device. BACKGROUND

[0002] The gas sensing device can monitor specific gas or multiple gases in real time, and convert gas concentration into electrical signal output, and is widely used in industrial production, environmental monitoring, medical health, safety protection and other fields.

[0003] At present, the gas sensing device is composed of a packaging structure and a sensing chip arranged in the packaging structure. The packaging structure has a gas hole, and external gas can enter the packaging structure through the gas hole to contact the sensing chip to monitor the gas through the sensing chip.

[0004] However, since the packaging structure is single-sided gas inlet, the flowability of the gas in the packaging structure is poor, and the sensing chip cannot be fully contacted, resulting in poor sensing accuracy of the sensing chip. Innovative content

[0005] The purpose of the embodiment of the application is to provide a gas sensing device to solve the technical problem of poor gas flow in the gas sensing assembly in the prior art.

[0006] To achieve the above purpose, the application provides a gas sensing device, which comprises a packaging body and a gas sensing chip. The packaging body comprises a base portion and a surrounding portion connected to the base portion. The surrounding portion and the base portion form a cavity in the packaging body. The cavity has a cavity opening on the side opposite to the base portion, which allows gas to enter and exit. The base portion is provided with a circuit pattern and a plurality of airflow holes penetrating the base portion. The gas sensing chip is located in the cavity and is arranged on the base portion and electrically connected to the circuit pattern. One of the airflow holes is located directly below the gas sensing chip opposite to the cavity. At least one of the other airflow holes is in communication with the cavity and is not located directly below the gas sensing chip.

[0007] In some embodiments, the gas sensing chip comprises a first electrode layer, a first insulating layer, a heating layer, a second insulating layer, a second electrode layer and a substrate layer arranged along a first direction, the first electrode layer is provided with a first gas sensitive layer, and the first gas sensitive layer is in contact with the first electrode layer, the second electrode layer is provided with a second gas sensitive layer, and the second gas sensitive layer is in contact with the second electrode layer, the first gas sensitive layer is configured to interact with a to-be-detected gas to change its electrical properties, the substrate layer has a hollow area opposite to the second gas sensitive layer, the second gas sensitive layer is in contact with the space in the hollow area, and the hollow area is opposite to the gas flow hole below the gas sensing chip.

[0008] In some embodiments, the packaging body further comprises a top cover portion and a first waterproof and breathable film, the top cover portion is connected to one side of the peripheral portion away from the base portion, and the top cover portion is provided with a first ventilation hole in communication with the cavity, and the first waterproof and breathable film is arranged on the top cover portion and covers the first ventilation hole.

[0009] In some embodiments, a first positioning portion is protruded on the inner wall of the first ventilation hole, and the first waterproof and breathable film is embedded in the first ventilation hole and abuts against one side of the first positioning portion away from the cavity.

[0010] In some embodiments, the packaging body further comprises a bottom cover portion and a second waterproof and breathable film, the bottom cover portion is connected to one side of the base portion away from the peripheral portion, the bottom cover portion is provided with a second ventilation hole in communication with the gas flow hole, and the second waterproof and breathable film is arranged on the bottom cover portion and covers the second ventilation hole.

[0011] In some embodiments, a second positioning portion is protruded on the inner wall of the second ventilation hole, and the second waterproof and breathable film is embedded in the second ventilation hole and abuts against one side of the second positioning portion away from the cavity.

[0012] In some embodiments, the packaging body further comprises a conductive pin, the conductive pin is arranged on the base portion, and the conductive pin is electrically connected with the circuit pattern, and one end of the conductive pin away from the base portion is lower than the base portion.

[0013] In some embodiments, the base portion and the peripheral portion are integrally formed.

[0014] In some embodiments, the top cover portion and the peripheral portion are integrally formed.

[0015] In some embodiments, the packaging body comprises a circuit board, the base portion is connected to the circuit board, the gas sensing chip is electrically connected to the circuit board, the circuit board is provided with a gas permeable hole, and the airflow hole is in communication with the gas permeable hole.

[0016] The gas sensing device provided by the present application has the beneficial effect that, during use of the gas sensing device, external gas can enter through the cavity opening of the cavity and be discharged from the airflow hole of the base portion, or enter the cavity from the airflow hole of the base portion and be discharged from the cavity opening, thereby forming a gas flow in the cavity that flows from the cavity opening to the airflow hole or from the airflow hole to the cavity opening, improving the flowability of the gas in the cavity, enabling the gas to fully contact the gas sensing chip in the cavity, and improving the sensing accuracy and sensing efficiency of the gas sensing chip for the gas. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0018] Figure 1 FIG. 1 is a structural schematic diagram of a gas sensing device in a first exemplary embodiment of the present application;

[0019] Figure 2 FIG. 2 is an exploded schematic diagram of the gas sensing device in the first exemplary embodiment of the present application; Figure 1 FIG. 3 is a sectional view in the A-A direction of the gas sensing device in the first exemplary embodiment of the present application;

[0020] Figure 3 FIG. 4 is a structural schematic diagram of a gas sensing chip in the first exemplary embodiment of the present application;

[0021] Figure 4 FIG. 5 is a structural schematic diagram of a gas sensing device in a second exemplary embodiment of the present application;

[0022] Figure 5 FIG. 6 is an exploded schematic diagram of the gas sensing device in the second exemplary embodiment of the present application;

[0023] Figure 6 FIG. 7 is a sectional view in the A-A direction of the gas sensing device in the second exemplary embodiment of the present application;

[0024] Figure 7 FIG. 8 is a structural schematic diagram of a gas sensing device in a third exemplary embodiment of the present application;

[0025] Figure 8 FIG. 9 is a structural schematic diagram of the gas sensing device in the third exemplary embodiment of the present application from another perspective;

[0026] In the drawings, reference numerals:

[0027] 100 - package body; 101 - cavity; 110 - base portion; 111 - circuit pattern; 112 - air flow hole; 120 - peripheral portion; 130 - top cover portion; 131 - first vent hole; 132 - first positioning portion; 140 - first waterproof and air permeable film; 150 - bottom cover portion; 151 - second vent hole; 152 - second positioning portion; 160 - second waterproof and air permeable film; 170 - conductive pin; 180 - circuit board; 181 - air permeable hole;

[0028] 200 - gas sensing chip; 210 - first electrode layer; 211 - first gas sensitive layer; 220 - first insulation layer; 230 - heating layer; 240 - second insulation layer; 250 - second electrode layer; 251 - second gas sensitive layer; 260 - base layer. DETAILED DESCRIPTION

[0029] In order to make the technical problems to be solved, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0030] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0031] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0032] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0033] The embodiments of the present application provide a gas sensing device, with reference to Figures 1-8The gas sensing device comprises a package body 100 and a gas sensing chip 200. The package body 100 comprises a base portion 110 and a surrounding portion 120 connected to the base portion 110. The surrounding portion 120 and the base portion 110 jointly define a cavity 101 in the package body 100. The cavity 101 has an opening on a side opposite to the base portion 110, through which gas can enter or exit. The base portion 110 is provided with a circuit pattern 111 and a plurality of airflow holes 112. The gas sensing chip 200 is located in the cavity 101, is arranged on the base portion 110 and is electrically connected to the circuit pattern 111. One of the airflow holes 112 is located directly below the gas sensing chip 200, and at least one other airflow hole 112 is in communication with the cavity 101 and is not located directly below the gas sensing chip 200.

[0034] Specifically, the base portion 110 and the surrounding portion 120 are made of a semiconductor material, such as monocrystalline silicon. The base portion 110 is a component with a certain area, and the shape of the base portion 110 can be arbitrary, for example, the base portion 110 is rectangular. The surrounding portion 120 is composed of a plurality of side walls arranged around the side of the base portion 110. The number of side walls constituting the surrounding portion 120 can be the same as the number of sides of the base portion 110. For example, when the shape of the base portion 110 is rectangular, the surrounding portion can be composed of four side walls arranged around the base portion 110 to jointly define the cavity 101 in the package body 100 with the base portion 110. The base portion 110 and the surrounding portion 120 can be integrally formed.

[0035] The circuit pattern 111 is a conductive structure embedded on the surface of the base portion 110 facing the cavity 101, which is made of conductive material. After the gas sensing chip 200 is fixed on the base portion 110, the circuit pattern 111 is electrically connected to the gas sensing chip 200. The shape of the circuit pattern 111 can be arbitrary and can be adapted according to the connection mode of the circuit pattern 111 and the gas sensing chip 200.

[0036] The airflow hole 112 is a through hole structure arranged through the base portion 110. The shape of the airflow hole 112 can also be arbitrary, for example, the shape of the airflow hole 112 is circular. The number of airflow holes 112 can be arranged in the base portion 110 in an interval, which reserves more installation space for the gas sensing chip 200 under the premise of ensuring the gas flow area.

[0037] The gas sensing chip 200 is an integrated electronic device for detecting gas. The gas sensing chip 200 can be fixed on the base portion 110 by means of adhesion, welding or the like, and electrically connected with the circuit pattern 111 of the base portion 110. After the gas sensing device is connected in an electronic device, the gas sensing chip 200 can be electrically connected with the circuit in the electronic device through the circuit pattern 111. In use, the gas from the outside can enter the cavity 101 through the cavity opening and be discharged from the airflow hole 112, or enter the cavity 101 from the airflow hole 112 and be discharged from the cavity opening, so as to improve the flowability of the gas in the cavity 101, and enable the gas to fully enter the cavity 101 and contact the gas sensing chip 200 in the cavity 101, thereby improving the sensing accuracy and efficiency of the gas.

[0038] With reference to Figure 4 In some embodiments, the gas sensing chip 200 comprises a first electrode layer 210, a first insulating layer 220, a heating layer 230, a second insulating layer 240, a second electrode layer 250 and a base layer 260 arranged in a first direction. The first electrode layer 210 is provided with a first gas sensitive layer 211, and the first gas sensitive layer 211 is in contact with the first electrode layer 210. The second electrode layer 250 is provided with a second gas sensitive layer 251, and the second gas sensitive layer 251 is in contact with the second electrode layer 250. The first gas sensitive layer 211 is configured to interact with the gas to be detected, so that the electrical properties thereof are changed. The base layer 260 has a hollow area opposite to the second gas sensitive layer 251. The second gas sensitive layer 251 is in contact with the space in the hollow area, and the hollow area is opposite to the airflow hole 112 directly below the gas sensing chip 200.

[0039] The first gas sensitive layer 211 and the second gas sensitive layer 251 are both used to interact with the gas to be detected, and change the electrical properties of the first gas sensitive layer 211 and the second gas sensitive layer 251. Specifically, the electrical properties of the first gas sensitive layer 211 and the second gas sensitive layer 251 will change when they are in contact with the gas to be detected. When the concentration of the gas to be detected changes, the electrical properties of the first gas sensitive layer 211 and the second gas sensitive layer 251 will also change.

[0040] The first gas sensitive layer 211 and the second gas sensitive layer 251 can be a metal oxide semiconductor material layer, for example, an N-type metal oxide semiconductor material, a P-type metal oxide semiconductor material, or a PN dual metal oxide semiconductor material. The N-type metal oxide semiconductor material can be MgO, CaO, TiO2, ZrO2, V2O5, Nb2O5, Ta2O5, MoO3, WO3, ZnO, Al2O3, Ga2O3, In2O3, or SnO2. The P-type metal oxide semiconductor material can be Y2O3, La2O3, CeO2, Mn2O3, Co3O4, NiO, PdO, Ag2O, Bi2O3, Sb2O3, or TeO2. The PN dual metal oxide semiconductor material can be HfO2, Cr2O3, Fe2O3, or CuO. In addition, the first gas sensitive layer 211 and the second gas sensitive layer 251 can also be zinc oxide or titanium dioxide, which can detect carbon monoxide, hydrogen, oxygen, and other gases.

[0041] The electrical property can be resistance, capacitance, inductance, or the like. For example, when the gas sensitive layer of zinc oxide is exposed to oxygen, the resistance of the gas sensitive layer will change with the increase of the oxygen concentration. By measuring the change of the electrical property of the gas sensitive layer, it can be indirectly inferred or calculated whether the to-be-detected gas exists and the concentration change of the to-be-detected gas.

[0042] The first electrode layer 210 is made of a conductive material and is in contact with the first gas sensitive layer 211. Specifically, the first gas sensitive layer 211 is in contact with the first electrode layer 210 and a detection circuit. When the electrical property of the first gas sensitive layer 211 changes, the detection circuit can measure the change amount of the electrical property of the first gas sensitive layer 211 through the first electrode layer 210. The second electrode layer 250 is made of a conductive material and is in contact with the second gas sensitive layer 251. Specifically, the second gas sensitive layer 251 is in contact with the second electrode layer 250 and a detection circuit. When the electrical property of the second gas sensitive layer 251 changes, the detection circuit can measure the change amount of the electrical property of the second gas sensitive layer 251 through the second electrode layer 250.

[0043] The heating layer 230 can be a heating electrode or a heating coil, which can generate heat after being powered on, thereby increasing the temperature of the gas sensing chip 200, and in particular, keeping the temperature of the first gas sensitive layer 211 and the second gas sensitive layer 251 at a preset stable state, so as to improve the accuracy of gas detection.

[0044] The first insulating layer 220 is arranged between the first electrode layer 210 and the heating layer 230, and is made of insulating material, so as to insulate the first electrode layer 210 and the heating layer 230 from each other and avoid mutual conduction. The second insulating layer 240 is arranged between the second electrode layer 250 and the heating layer 230, and is made of insulating material, so as to insulate the second electrode layer 250 and the heating layer 230 from each other and avoid mutual conduction. The first insulating layer 220 and the second insulating layer 240 are made of insulating material, such as mica, asbestos fiber, phenolic acid ester and the like.

[0045] The first gas sensitive layer 211 can contact the to-be-detected gas, and the second gas sensitive layer 251 can be closed to not contact the to-be-detected gas and only contact the background gas. At this time, the materials, sizes, shapes, temperatures and other conditions of the first gas sensitive layer 211 and the second gas sensitive layer 251 are the same, so that the signal generated by the first gas sensitive layer 211 can be understood as a response signal, and the signal generated by the second gas sensitive layer 251 can be understood as a background signal. The response signal and the background signal are subtracted to filter out the background noise signal. Whether the temperature of the gas sensitive layer reaches a steady state or not, the signal fluctuation before the temperature reaches the steady state can be filtered out, the problem of long starting time of the traditional gas sensing chip 200 is solved, the signal-to-noise ratio is improved, and the misjudgment rate is reduced. Similarly, the first gas sensitive layer 211 can be closed, and the second gas sensitive layer 251 can contact the to-be-detected gas.

[0046] The materials and other conditions of the first gas sensitive layer 211 and the second gas sensitive layer 251 are different, different to-be-detected gases can be detected, and the signals generated by the first gas sensitive layer 211 and the second gas sensitive layer 251 are both response signals. Different gas sensitive layers can detect different gases.

[0047] The substrate layer 260 is arranged on the side of the second electrode layer 250 away from the second insulating layer 240, and can be any one of a silicon wafer, a glass sheet, a quartz sheet, an aluminum oxide ceramic sheet, an aluminum nitride ceramic sheet, a silicon nitride ceramic sheet, a silicon carbide ceramic sheet, a zirconium oxide ceramic sheet and a polyimide film.

[0048] After the gas sensing chip 200 is installed in the chamber 101, the first gas sensing layer 211 faces the opening of the chamber 101, allowing communication with the external environment. External gas can enter the chamber 101 through the opening and come into contact with the first gas sensing layer 211. The substrate layer 260 is connected to the base, and the hollowed-out area faces at least one airflow hole 112 provided on the base, allowing communication with the external environment through the airflow hole 112, so that air from the external environment can enter the gas cavity and come into contact with the second gas sensing layer 251. Since the hollowed-out area, the base, and the corresponding airflow hole 112 on the base form a detection gas cavity, the first gas sensing layer 211 and the second gas sensing layer 251 can detect different gases and their corresponding concentrations respectively. Other airflow holes 112 not located directly below the gas sensing chip 200 can increase the flow of air in the chamber 101, improving the gas sensing accuracy of the first gas sensing layer 211.

[0049] like Figures 1-3 As shown, in some embodiments, the base 110 in the package body 100 can be horizontally arranged, the surrounding portion 120 is connected above the base 110, the cavity opening of the chamber 101 is located at the upper part of the package body 100, the airflow hole 112 is located at the bottom of the package body 100, and the gas sensing chip 200 is horizontally mounted on the base 110 to be able to sense gas flowing in the vertical direction.

[0050] Furthermore, the encapsulation body 100 also includes a top cover 130 and a first waterproof and breathable membrane 140. The top cover 130 is connected to the side of the peripheral portion 120 facing away from the base 110, and the top cover 130 is provided with a first vent 131 communicating with the chamber 101. The first waterproof and breathable membrane 140 is disposed on the top cover 130 and covers the first vent 131.

[0051] Specifically, the top cover 130 can be made of liquid crystal polymer (LCP) material. The shape of the top cover 130 can be the same as the top outer contour shape of the peripheral part 120 and cover and connect to the top of the peripheral part 120. For example, the top cover 130 is rectangular and its four sides are connected to the four side walls of the peripheral part 120.

[0052] The shape of the first vent 131 can be arbitrary, for example, the first vent 131 is circular. The first vent 131 is provided through the top cover portion 130 and can be located at the center of the top cover portion 130 to connect the chamber 101 and the external space, so that external gas can enter and exit the chamber 101 through the first vent 131.

[0053] The first waterproof and breathable membrane 140 can be an EPTFE film, and the first waterproof and breathable membrane 140 has a microporous structure to allow gas to pass through and block water molecules and fine particles. The shape of the first waterproof and breathable membrane 140 can be the same as that of the first air hole 131, for example, the first waterproof and breathable membrane 140 is circular. The area of the first waterproof and breathable membrane 140 can be the same as that of the first air hole 131 and embedded in the first air hole 131 to shield the first air hole 131; or the area of the first waterproof and breathable membrane 140 can be greater than that of the first air hole 131 and connected to the upper surface or the lower surface of the top cover portion 130 to completely shield the first air hole 131.

[0054] Further, the inner wall of the first air hole 131 can be provided with a first positioning portion 132, and the first waterproof and breathable membrane 140 is embedded in the first air hole 131 and abuts against one side of the first positioning portion 132 away from the cavity 101. The first positioning portion 132 is a limiting structure protruding on the inner wall of the first air hole 131, and the first positioning portion 132 can be integrally formed on the top cover portion 130. The shape of the first positioning portion 132 can be annular. In addition, the shape of the first positioning portion 132 can also be other shapes, for example, the first positioning portion 132 is a plurality of block structures protruding on the inner wall of the first air hole 131. The first waterproof and breathable membrane 140 can be connected to the upper surface of the first positioning portion 132 by bonding or the like to fix the installation position of the first waterproof and breathable membrane 140 in the first air hole 131.

[0055] By shielding the first air hole 131 with the first waterproof and breathable membrane 140, dust or water droplets can be blocked from entering the cavity 101, which protects the gas sensing chip 200 under the premise of ensuring smooth gas flow, avoids the gas sensing chip 200 from being damp and polluted, and ensures the accuracy of the gas sensing chip 200 in sensing gas.

[0056] Further, the packaging body 100 further comprises a bottom cover portion 150 and a second waterproof and breathable membrane 160, the bottom cover portion 150 is connected to one side of the base portion 110 away from the surrounding portion 120, and the bottom cover portion 150 is provided with a second air hole 151 communicating with the airflow hole 112, and the second waterproof and breathable membrane 160 is arranged on the bottom cover portion 150 and shields the second air hole 151.

[0057] Specifically, the bottom cover portion 150 can also be made of liquid crystal polymer (LCP) material, and the shape of the bottom cover portion 150 can be the same as that of the base portion 110, for example, the shape of the bottom cover portion 150 is rectangular and is fixed to the bottom surface of the base portion 110 by bonding or the like.

[0058] The shape of the second vent hole 151 can be arbitrary, for example, the second vent hole 151 is circular. The second vent hole 151 is arranged through the bottom cover portion 150 and can be located at the center position of the bottom cover portion 150. The area of the second vent hole 151 can be large, and the base portion 110 can be provided with air flow holes 112 at the position exposed to the second vent hole 151, and all the air flow holes 112 are located at the second vent hole 151, so as to communicate the second vent hole 151 and all the air flow holes 112, so that the external gas can enter and exit the chamber 101 through the second vent hole 151 and the plurality of air flow holes 112 in sequence.

[0059] The second waterproof and breathable film 160 can also be an EPTFE film. The second waterproof and breathable film 160 has a microporous structure that allows gas to pass through and blocks water molecules and fine particles, and can block water or dust and other pollutants carried in the gas from entering the chamber 101 through the air flow holes 112, thereby protecting the gas sensing chip 200 in the chamber 101.

[0060] The shape of the second waterproof and breathable film 160 can be the same as that of the second vent hole 151, for example, the second waterproof and breathable film 160 is circular. The area of the second waterproof and breathable film 160 can be the same as that of the second vent hole 151 and embedded in the second vent hole 151 to shield the second vent hole 151; the area of the second waterproof and breathable film 160 can also be larger than that of the second vent hole 151 and connected to the upper surface or the lower surface of the bottom cover portion 150 to completely shield the second vent hole 151.

[0061] Further, the inner wall of the second vent hole 151 can be provided with a second positioning portion 152, and the second waterproof and breathable film 160 is embedded in the second vent hole 151 and abuts against the side of the second positioning portion 152 away from the chamber 101. The second positioning portion 152 is a limiting structure protruding on the inner wall of the second vent hole 151, and the second positioning portion 152 can be integrally formed on the bottom cover portion 150. The shape of the second positioning portion 152 can also be annular. The second waterproof and breathable film 160 can also be connected to the upper surface of the second positioning portion 152 by adhesion or the like, so as to fix the installation position of the second waterproof and breathable film 160 in the second vent hole 151.

[0062] Further, the packaging body 100 further comprises a conductive pin 170, the conductive pin 170 is arranged on the base portion 110, and part of the conductive pin 170 is exposed in the cavity and electrically connected with the circuit pattern 111. The end of the conductive pin 170 away from the base portion 110 is lower than the base portion 110.

[0063] Specifically, the conductive pin 170 can be made of conductive materials such as copper, aluminum, graphite, and ceramic. The portion of the base portion 110 corresponding to the conductive pin 170 can be provided with a groove, and the conductive pin 170 is embedded in the groove, so that one side surface of the conductive pin 170 can be exposed in the chamber 101. The conductive pin 170 can be electrically connected to the circuit pattern 111 of the base portion 110 by welding or the like, and in addition, the conductive pin 170 can be integrally formed with the circuit pattern 111. The number of conductive pins 170 can be adaptively set according to the connection requirements of the gas sensing chip 200, and this embodiment does not make specific limitations.

[0064] When the gas sensing device is installed in an electronic device, the end of the conductive pin 170 away from the base portion 110 is welded to the control board of the electronic device, so that the control board is connected to the gas sensing chip 200 in the chamber 101 through the conductive pin 170 and the circuit pattern 111 to transmit electrical signals.

[0065] In addition, the end of the conductive pin 170 away from the base portion 110 is lower than the base portion 110. When the bottom of the base portion 110 is provided with the bottom cover portion 150, the bottom of the conductive pin 170 should be lower than the bottom cover portion 150. After the conductive pin 170 is welded on the control board, the bottom cover portion 150 can be supported on the upper side of the control board, so that an air flow gap is reserved between the bottom of the bottom cover portion 150 and the control board, and the gas can enter and exit the chamber 101 through the second air hole 151 and the air flow hole 112.

[0066] As shown in Figure 5 and Figure 6 In some embodiments, the base portion 110 can also be vertically arranged, and the surrounding portion 120 is connected to one side of the base portion 110, so that the chamber opening of the chamber 101 faces the horizontal direction, and a plurality of air flow holes 112 are arranged along the horizontal direction, so that the gas can enter and exit the chamber 101 along the horizontal direction. The gas sensing chip 200 can be vertically connected to the base portion 110 to be able to sense the gas flowing in the horizontal direction. Among them, the base portion 110 and the surrounding portion 120 can be integrally formed. In addition, the conductive pin 170 can be vertically connected to the base portion 110, and the bottom end of the conductive pin 170 extends below the base portion 110.

[0067] Referring to Figure 7 and Figure 8In some embodiments, when the packaging body 100 is composed of the base portion 110, the surrounding portion 120 and the top cover portion 130, the surrounding portion 120 and the top cover portion 130 can be integrally formed, and the bottom end of the surrounding portion 120 is connected to the upper surface of the base portion 110 by means of bonding or welding, etc. to form a cavity 101 for packaging the gas sensing chip 200 between the base portion 110, the surrounding portion 120 and the top cover plate, and the base portion 110 is also provided with a plurality of airflow holes 112, the top cover portion 130 is provided with a first air hole 131 and a first waterproof and air-permeable film 140 to ensure the flowability of the airflow in the cavity 101.

[0068] In the present embodiment, the packaging body 100 can further include a circuit board 180 connected to the side of the base portion 110 opposite to the surrounding portion 120, the conductive pins 170 are electrically connected to the circuit board 180, and the circuit board 180 is provided with an air-permeable hole 181, and the airflow holes 112 are in communication with the air-permeable hole 181.

[0069] The plurality of conductive pins 170 on the base portion 110 can be welded to the electrically conductive contacts of the circuit board 180 to electrically connect the gas sensing chip 200 and the circuit of the circuit board 180 through the conductive pins 170 and the circuit pattern 111 of the base portion 110, so that the entire gas sensing device forms a patch type structure, and the gas sensing device can be installed in an electronic device through the circuit board 180. The shape of the air-permeable hole 181 can be arbitrary, for example, the shape of the air-permeable hole 181 is rectangular. The width of the air-permeable hole 181 can be smaller than the width of the base portion 110, and the part of the base portion 110 where the airflow holes 112 are opened is opposite to the position of the air-permeable hole 181, so that all the airflow holes 112 are exposed at the air-permeable hole 181, and the gas can enter and exit the inside of the cavity 101 through the air-permeable hole 181 of the circuit board 180 and the airflow holes 112 of the base portion 110, to ensure the flowability of the gas in the cavity 101.

[0070] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A gas sensing device, characterized by, The package body includes a base portion and a surrounding portion connected to the base portion, a cavity is formed between the surrounding portion and the base portion, a side of the cavity opposite to the base portion has a cavity opening for gas to enter or exit, the base portion is provided with a circuit pattern and a plurality of airflow holes penetrating through the base portion, and the gas sensing chip is located in the cavity, arranged on the base portion and electrically connected with the circuit pattern, wherein one of the airflow holes is located directly below the gas sensing chip, and at least another one of the airflow holes is in communication with the cavity and not located directly below the gas sensing chip.

2. The gas sensing device of claim 1, wherein, The gas sensing chip includes a first electrode layer, a first insulating layer, a heating layer, a second insulating layer, a second electrode layer and a substrate layer arranged in a first direction, the first electrode layer is provided with a first gas sensitive layer, and the first gas sensitive layer is in contact with the first electrode layer, the second electrode layer is provided with a second gas sensitive layer, and the second gas sensitive layer is in contact with the second electrode layer, the first gas sensitive layer is configured to interact with the to-be-detected gas to change its electrical properties, the substrate layer has a hollow area opposite to the second gas sensitive layer, the second gas sensitive layer is in contact with the space in the hollow area, and the hollow area is opposite to the airflow hole located directly below the gas sensing chip.

3. The gas sensing device of claim 1, wherein, The package body further includes a top cover portion and a first waterproof and breathable membrane, the top cover portion is connected to a side of the surrounding portion opposite to the base portion, and the top cover portion is provided with a first air hole in communication with the cavity, and the first waterproof and breathable membrane is arranged on the top cover portion and covers the first air hole.

4. A gas sensing device according to claim 3, characterised in that, A first positioning portion is protruded on an inner wall of the first air hole, and the first waterproof and breathable membrane is embedded in the first air hole and abuts against a side of the first positioning portion opposite to the cavity.

5. The gas sensing device of claim 3, wherein, The package body further includes a bottom cover portion and a second waterproof and breathable membrane, the bottom cover portion is connected to a side of the base portion opposite to the surrounding portion, the bottom cover portion is provided with a second air hole in communication with the airflow hole, and the second waterproof and breathable membrane is arranged on the bottom cover portion and covers the second air hole.

6. A gas sensing device according to claim 5, characterised in that, A second positioning portion is protruded on an inner wall of the second air hole, and the second waterproof and breathable membrane is embedded in the second air hole and abuts against a side of the second positioning portion opposite to the cavity.

7. A gas sensing device according to any one of claims 3-6, characterised in that, The package body further includes a conductive pin, the conductive pin is arranged on the base portion, and the conductive pin is electrically connected with the circuit pattern, and an end of the conductive pin away from the base portion is lower than the base portion.

8. A gas sensing device according to claim 7, characterised in that, The base portion and the surrounding portion are integrally formed.

9. The gas sensing device of claim 7, wherein, The top cover portion and the surrounding portion are integrally formed.

10. The gas sensing device of claim 3, wherein, The package body includes a circuit board, the base portion is connected to the circuit board, the gas sensing chip is electrically connected with the circuit board, the circuit board is provided with a breathable hole, and the airflow hole is in communication with the breathable hole.

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