CN218917266U - Hot wire type gas sensor chip and sensor - Google Patents

Abstract

The application relates to a hot wire type gas sensor chip, which comprises a substrate, a gas sensing component and a temperature sensing layer. The gas sensing component comprises a heating electrode, a heating resistor and a semiconductor gas-sensitive layer, wherein the heating electrode and the heating resistor are arranged on the substrate, the heating resistor is electrically connected with the heating resistor, and the semiconductor gas-sensitive layer is covered on the heating resistor. The temperature sensing layer is arranged on the substrate and is positioned outside the area where the gas sensing component is positioned. According to the hot wire type gas sensor chip, the temperature sensing layer is arranged on the substrate, so that a compensation element is not needed, one substrate can be reduced, the cost can be reduced, the power consumption of power supply is reduced, the pairing operation is omitted, the packaging test is simpler, and meanwhile, the sensor baseline drift caused by long-term work of the detection element and the compensation element can be avoided.

Description

Hot wire type gas sensor chip and sensor

Technical Field

The utility model relates to the technical field of electronic devices, in particular to a hot wire type gas sensor chip and a sensor.

Background

This section provides merely background information related to the present disclosure and is not necessarily prior art.

The existing gas sensor has various types and wide application range, wherein the hot wire type gas sensor consists of a detection element and a compensation element, uses semiconductor metal oxide as a sensitive material, retains the advantage of high sensitivity of the traditional semiconductor metal oxide, and compensates the environmental temperature and humidity change by using the compensation element at the same time, so that the gas sensor has better environmental temperature and humidity stability.

The existing hot wire type semiconductor gas sensor is basically prepared by hand at present, and the main flow is as follows: and manually winding a platinum wire into a miniature coil with a specific length, respectively manually smearing a gas sensitive material and a gas insensitive material on the platinum wire coil, and drying and sintering to obtain a gas sensitive detection element and a gas insensitive compensation element, wherein the two elements form the hot wire type semiconductor gas sensor. Platinum wire coils are also known by the name of the hot wire type as both heating coils and detection signal electrodes in such sensors. However, the hot-line type semiconductor gas sensor is basically prepared by hand, the degree of automation is not high, the product yield is low, the consistency is poor, and the sensor power consumption is high, so that the development and popularization of the sensor are limited.

Disclosure of Invention

The object of the present utility model is to solve at least one of the above-mentioned problems. The aim is achieved by the following technical scheme:

embodiments of the present application propose a hot wire gas sensor chip including:

a substrate;

the gas sensing assembly comprises a heating electrode, a heating resistor and a semiconductor gas-sensitive layer, wherein the heating electrode and the heating resistor are arranged on the substrate, the heating resistor is electrically connected with the heating resistor, and the semiconductor gas-sensitive layer covers the heating resistor; a kind of electronic device with high-pressure air-conditioning system

The temperature sensing layer is arranged on the substrate and is positioned outside the area where the gas sensing component is positioned.

According to the embodiment of the application, the temperature sensing layer is arranged on the substrate, the temperature sensing layer is used for acquiring the parameter of the environmental temperature change to compensate the resistance change of the gas sensing component, compared with a traditional hot wire type gas sensor, the temperature sensing layer can be used for eliminating a compensation element, so that one substrate can be reduced, the cost can be reduced, the power consumption of power supply can be reduced, the pairing operation can be omitted, the packaging test is simpler, and meanwhile, the sensor baseline caused by long-term work of the detection element and the compensation element can be avoided from drifting.

In addition, main elements such as a heating electrode, a heating resistor, a temperature sensing layer and the like on the hot wire type gas sensor chip can be prepared by adopting slurry to form a film and sintering at a high temperature, so that the automation degree is high, and the product robustness is good.

In addition, the hot wire type gas sensor chip according to the embodiment of the utility model may further have the following additional technical features:

in one embodiment, the temperature sensing layer includes a temperature sensing electrode and a temperature sensing film both disposed on the substrate, and the temperature sensing electrode is electrically connected to the temperature sensing film.

In one embodiment, the temperature sensing membrane has a width of 5 microns to 100 microns and a thickness of 0.1 microns to 20 microns.

In one embodiment, the temperature sensing membrane is disposed at least on one side of the gas sensing assembly, or the temperature sensing membrane is disposed around the gas sensing assembly.

In one embodiment, the temperature sensing membrane is spaced from the region of the gas sensing assembly by a distance of 200 microns to 2000 microns.

In one embodiment, the temperature sensing membrane is composed of one of a PTC thermistor, an NTC thermistor, a thermal resistor, and a thermocouple.

In one embodiment, the substrate comprises a silicon base and a ceramic film arranged on the silicon base, and the heating electrode, the heating resistor and the temperature sensing layer are all arranged on the surface of the ceramic film far away from the silicon base.

In one embodiment, the ceramic film has a thickness of 1 micron to 50 microns.

In one embodiment, the silicon substrate comprises a first surface and a second surface opposite to the first surface, the ceramic film is arranged on the second surface, the silicon substrate comprises a heating zone in the center and a supporting zone surrounding the heating zone, the heating zone is provided with an adiabatic air cavity penetrating through the first surface and the second surface, and the heating resistor is arranged at a position corresponding to the heating zone of the ceramic film.

The application also provides a hot wire type gas sensor, including above-mentioned arbitrary hot wire type gas sensor chip, still include encapsulation shell, hot wire type gas sensor chip sets up in the encapsulation shell, be provided with the pin on the encapsulation shell, the heating electrode with the pin electricity is connected.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the utility model. Also, like reference numerals are used to designate like parts throughout the figures. In the drawings:

FIG. 1 is a schematic diagram of a hot wire gas sensor chip according to an embodiment of the utility model;

FIG. 2 is a schematic diagram of a structure of the hot wire gas sensor chip shown in FIG. 1 from another view angle;

FIG. 3 is a schematic diagram of a hot wire gas sensor chip according to another embodiment of the present utility model;

FIG. 4 is a schematic diagram of a hot wire gas sensor chip according to another embodiment of the present utility model;

fig. 5 is a schematic diagram of a hot wire gas sensor according to an embodiment of the utility model.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For ease of description, spatially relative terms, such as "inner," "outer," "lower," "below," "upper," "above," and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative relationship descriptors used herein interpreted accordingly.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used herein in the description of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

In the present application, a range expressed by "one value to another value" is a general expression which avoids the specification from listing all the values in the range. Thus, recitation of a particular numerical range includes any numerical value within that range, as well as the smaller numerical range bounded by any numerical value within that range, as if the any numerical value and the smaller numerical range were written in the specification in the clear.

Referring to fig. 1, a hot wire gas sensor chip 100 according to a first embodiment of the present disclosure includes a substrate 110, a gas sensing element 120 and a temperature sensing layer 130, wherein the gas sensing element 120 and the temperature sensing layer 130 are disposed on the substrate 110, and the temperature sensing layer 130 is disposed outside an area where the gas sensing element 120 is disposed.

With continued reference to fig. 1, the substrate 110 includes a silicon substrate 111 and a ceramic film 112 disposed on the silicon substrate 111, and the gas sensor assembly 120 and the temperature sensor layer 130 are disposed on a surface of the ceramic film 112 away from the silicon substrate 111. In one embodiment, the silicon substrate 111 is selected from a double-sided oxidized, single-sided oxidized, or unoxidized monocrystalline silicon wafer having a crystal orientation of 100 or 111, or a polycrystalline silicon wafer. In one embodiment, the thickness of the silicon substrate 111 is 50 microns to 700 microns. In one embodiment, ceramic membrane 112 is composed of a glass and ceramic system, or a glass-ceramic system, or a single-phase ceramic. In one embodiment, ceramic membrane 112 has a thickness of 1 micron to 50 microns.

With continued reference to fig. 1, the silicon substrate 111 includes a first surface 1111 and a second surface 1112 opposite to the first surface 1111, the ceramic film 112 is disposed on the second surface 1112, the silicon substrate 111 includes a central heating region and a supporting region disposed around the heating region, the heating region has an insulating air cavity 1115 penetrating the first surface 1111 and the second surface 1112, and the gas sensing component 120 is disposed at a position of the ceramic film 112 corresponding to the heating region. By providing the insulating air cavity 1115 on the silicon substrate 111, the substrate 110 has a smaller heat capacity and a faster response to heat due to the lower thermal conductivity of air, which provides good thermal insulation.

With continued reference to fig. 1, the gas sensing component 120 includes a heating electrode 121, a heating resistor 122 and a semiconductor gas-sensitive layer 123, wherein the heating electrode 121 and the heating resistor 122 are disposed on the substrate 110, the heating resistor 122 is electrically connected to the heating electrode 121, and the semiconductor gas-sensitive layer 123 covers the heating resistor 123. Specifically, heating resistor 122 and heating electrode 121 are both disposed on ceramic membrane 112, and heating resistor 122 is located at a position of ceramic membrane 112 corresponding to insulating air chamber 1115. The heating electrode 121 mainly provides an external electric signal for the substrate 110, the heating electrode 121 is a conductive pad with a certain area, and a conductive wire can be welded on the heating electrode 121, so that the heating electrode 121 is electrically connected with an external circuit through the conductive wire. In one embodiment, the heater electrode 121 is selected from any one of platinum, gold, silver, copper, aluminum, nickel, tungsten, silver/palladium, platinum/gold. In one embodiment, heater electrode 121 has a thickness of 0.1 microns to 50 microns. The heating electrode 121 may be manufactured by screen printing a metal paste of the heating electrode 121 and sintering at a high temperature. The heating resistor 122 is a main heating element, and when external current is transmitted to the heating resistor 122 through the heating electrode 121, the heating resistor 122 generates heat joule heat, thereby providing a heat source to the substrate 110. In one embodiment, the heating resistor 122 is made of any one of antimony tin oxide, indium tin oxide, fluorine doped tin dioxide, fluorine phosphorus co-doped tin dioxide, aluminum doped zinc oxide, ruthenium dioxide/silver composite, ruthenium dioxide/silver palladium composite. In one embodiment, the resistance of the heating resistor 122 is 10Ω -500Ω. In one embodiment, the heating resistor 122 has a thickness of 0.1 microns to 50 microns. The heating resistor 122 may be made by screen printing a paste of the heating resistor 122 and by high temperature sintering.

The semiconductor gas sensitive layer 123 has gas sensitive activity to combustible gases, volatile organic gases, sulfide gases, oxynitride gases, and other toxic gases, which can cause the electrical resistance of the semiconductor gas sensitive material layer to change, and the electrical resistance to increase or decrease, at the temperature provided by the heating resistor 122. Specifically, the semiconductor gas-sensitive layer 123 is composed of a metal oxide semiconductor such as tungsten oxide, indium oxide, zinc oxide, antimony oxide, nickel oxide, tin oxide, copper oxide, cobalt oxide, iron oxide, chromium oxide, cerium oxide, vanadium oxide, zirconium oxide, or the like. In one embodiment, the resistance of the semiconductor gas sensitive layer 123 is 5KΩ -500KΩ.

With continued reference to fig. 1, the temperature sensing layer 130 is disposed on the ceramic film 112, and the temperature sensing layer 130 is located outside the region of the gas sensing element 120. The temperature sensing layer 130 includes a temperature sensing electrode 131 and a temperature sensing film 132 both disposed on the ceramic film 112, and the temperature sensing electrode 131 is electrically connected to the temperature sensing film 132. In one embodiment, the temperature sensing electrode 131 is selected from any one of platinum, gold, silver, copper, aluminum, nickel, tungsten, silver/palladium, platinum/gold. The thickness of the temperature sensing electrode 131 is 0.1 micrometers to 50 micrometers.

Referring to fig. 2, the temperature sensor film 132 is disposed on one side of the gas sensor assembly 120. In another embodiment, referring to FIG. 3, a temperature sensing membrane 132 is disposed around the gas sensing assembly 120. In one embodiment, the temperature sensing film 132 is 200 microns to 2000 microns from the region of the gas sensing element 120. In one embodiment, the temperature sensing film 132 has a width of 5 micrometers to 100 micrometers and a thickness of 0.1 micrometers to 20 micrometers, so that the temperature sensing film 132 has a suitable resistance value.

The temperature sensing film 132 is composed of one of PTC thermistor, NTC thermistor, thermal resistor, thermocouple. Specifically, the PTC thermistor is prepared by mixing powder into slurry, printing and sintering, wherein barium titanate, strontium titanate or lead titanate are used as main components, and trace oxides of niobium, tantalum, bismuth, antimony, yttrium, lanthanum and the like are doped for regulation and control. The NTC thermistor is prepared by mixing two or more metal oxide powders of manganese, copper, silicon, cobalt, iron, nickel, zinc and the like to prepare slurry, and printing and sintering. The thermal resistor is prepared by printing and sintering metal conductor paste or metal oxide paste, wherein the metal paste is selected from any one of platinum, gold, silver, copper, aluminum, nickel, tungsten and molybdenum, and the metal oxide paste is selected from any one of ruthenium dioxide or tin dioxide-antimonous oxide. The thermocouple is composed of one of a platinum rhodium thermocouple, a nickel chromium-nickel silicon thermocouple, a nickel chromium silicon-nickel silicon thermocouple, a nickel chromium-copper nickel thermocouple and a copper-copper nickel thermocouple, and is prepared by printing and sintering corresponding slurry. Referring to fig. 4, a temperature sensing film 132 is disposed around the gas sensing assembly 120, and the temperature sensing film 132 is composed of one or more arrays of thermistors, thermal resistors, and thermocouples. In one embodiment, the temperature sensing film 132 is further provided with an insulating protection layer, and the thickness of the insulating protection layer is 0.1 micrometers to 20 micrometers.

The detection principle of the hot wire type gas sensor chip is as follows: the resistance of the heating resistor 122 is R ₀ The resistance of the semiconductor gas sensitive layer 123 is set to R ₁ The heating resistor 122 and the semiconductor gas sensitive layer 123 form good ohmic contact, and the total resistance of the heating resistor 122 and the semiconductor gas sensitive layer 123 is as follows according to the principle of series-parallel circuit

Resistance R of the semiconductor gas sensitive layer 123 when the target gas exists in the surrounding environment ₁ Will change to make the total resistance R of the heating resistor 122 and the semiconductor gas sensitive layer 123 _d Is changed according to R _d The change in (c) may be used to derive the concentration of the target gas. When the ambient temperature changes, the resistance of the temperature sensing film 132 also changes, and a signal is transmitted to the processor through the temperature sensing electrode 131 to obtain the change of the ambient temperature, so as to compensate the resistance drift of the gas sensing component 120 caused by the change of the ambient temperature, so that the hot wire type gas sensor chip 100 does not cause errors due to the change of the ambient temperature.

The application also provides a preparation method of the hot wire type gas sensor, which comprises the following steps:

s1, providing a substrate 110;

in one embodiment, providing the substrate 110 includes providing a silicon base 111 and fabricating a ceramic film 112 on the silicon base 111. In a specific embodiment, providing a substrate comprises the steps of: s11, selecting a double-sided oxidation monocrystalline silicon substrate with a crystal orientation of 100, then ultrasonically cleaning the monocrystalline silicon substrate for 10min by using acetone, ultrasonically cleaning the monocrystalline silicon substrate for 5min by using isopropanol, cleaning the monocrystalline silicon substrate for 5min by using deionized water, and drying the monocrystalline silicon substrate by using nitrogen; s12, selecting ceramic powder with proper specification, adding an organic carrier, preparing ceramic slurry, printing on a silicon substrate in a screen printing mode, and drying at a certain temperature; and S13, placing the dried silicon substrate into a muffle furnace for sintering to obtain the dense and hard ceramic film 112 with proper thickness.

S2, printing the heating electrode slurry, the heating resistor slurry and the temperature sensing layer slurry on the substrate 110 in a screen printing mode, and drying and sintering to respectively obtain a heating electrode 121, a heating resistor 122 and a temperature sensing layer 130;

specifically, the temperature sensing layer paste includes a temperature sensing electrode paste and a temperature sensing film paste, which are respectively printed on the substrate to obtain a temperature sensing electrode 131 and a temperature sensing film 132.

S3, printing a semiconductor gas-sensitive layer 123 on the heating resistor 122 by adopting a screen printing mode, and drying and sintering;

and S4, etching a region corresponding to the heating resistor on the surface of the substrate far away from the heating resistor 122 to form an adiabatic air cavity 1115, thereby obtaining the hot-wire gas sensor chip 100.

Specifically, photoresist is spin-coated on the surface of the silicon substrate 111 far away from the ceramic film 112, and is baked, then patterned exposure and patterned development are performed, silicon dioxide on the back surface is removed through a reactive ion etching technology, then unprotected silicon of photoresist on the lower part of the ceramic film is etched through a deep silicon etching technology, an adiabatic air cavity 1115 is formed, and finally a hot wire type gas sensor chip is obtained through a cutting technology.

According to the hot wire type gas sensor chip, the temperature sensing layer is arranged on the substrate, the temperature sensing layer is used for acquiring the parameter of the environmental temperature change to compensate the resistance change of the gas sensing component, compared with a traditional hot wire type gas sensor, the hot wire type gas sensor chip can be free of a compensation element, so that one substrate can be reduced, the cost can be reduced, the power consumption of power supply is reduced, the pairing operation is omitted, the packaging test is simpler, and meanwhile, the sensor base line caused by long-term work of the detection element and the compensation element can be prevented from drifting.

In addition, main elements such as a heating electrode, a heating resistor, a temperature sensing layer and the like on the hot wire type gas sensor chip can be prepared by adopting slurry to form a film and sintering at a high temperature, so that the automation degree is high, and the product robustness is good.

Referring to fig. 5, the present application further provides a hot wire type gas sensor 10, which includes a hot wire type sensor chip 100 and a package case 200, wherein the hot wire type gas sensor chip 100 is disposed in the package case 200, a pin 210 is disposed in the package case 200, and a heating electrode 121 is electrically connected with the pin 210.

The package housing 200 not only plays a role in mounting, fixing, protecting and enhancing heat conductive properties, but also serves as a bridge for communicating the inside of the sensor chip with the external circuit. The heater electrode 121 is connected to the leads 210 of the package housing 200 by wires 129, and the leads 210 establish connection with other devices by wires on a printed circuit board. In one embodiment, the package housing 200 comprises a ceramic package housing, a plastic package housing, and a metal package housing.

With continued reference to fig. 5, an explosion-proof and dust-proof air-permeable cap 220 is provided on the package housing 200 so that external air can smoothly enter the hot-wire type gas sensor 10. In one embodiment, the explosion-proof and dust-proof venting cap 220 is sintered from porous stainless steel powder or is composed of a porous sheet metal. In the illustrated embodiment, a waterproof and breathable membrane 230 is also provided on the explosion-proof and dust-proof cap 220 to prevent moisture from entering the hot wire gas sensor 10.

For a better illustration of the present application, some specific examples of the method for manufacturing a hot wire gas sensor chip are provided below.

Example 1

Providing a double-sided polished double-sided oxidized 4-inch monocrystalline silicon wafer with a 100 crystal orientation, then ultrasonically cleaning with acetone for 15min, ultrasonically cleaning with isopropanol for 5min, cleaning with deionized water for 5min, and drying with nitrogen; ceramic powder with proper specification is selected, an organic carrier is added to prepare ceramic slurry, the ceramic slurry is printed on a wafer in a screen printing mode, and the wafer is dried for 10min at 120 ℃; placing the dried wafer into a muffle furnace, and sintering at 1000 ℃ for 30min to obtain a dense and hard ceramic film with the thickness of 10 um;

printing a heating resistor array and a heating electrode array with the length and width of 300um multiplied by 300um on a ceramic film in a screen printing mode, and respectively obtaining a heating electrode, a heating resistor, a temperature sensing electrode and a temperature sensing film of an NTC thermistor with the length and width of 800um multiplied by 100um and a temperature sensing electrode with the length and width of 100um multiplied by 200um by drying at 120 ℃ for 5min and sintering at 850 ℃ for 15 min; printing a tin dioxide and antimony oxide mixed semiconductor gas-sensitive layer on a heating resistor by adopting a screen printing mode, drying at 120 ℃ for 5min, and sintering at 800 ℃ for 20min;

spin-coating positive photoresist on the back of a substrate, drying at 100 ℃ for 5min, performing patterned exposure and patterned development to obtain an unprotected region of the photoresist with the thickness of 10um and the length and width of 500um multiplied by 500um, removing silicon dioxide in the unprotected region by a reactive ion etching technology, etching the unprotected silicon of the photoresist by a deep silicon etching technology to form an adiabatic air cavity, and obtaining the hot wire type gas sensor with the length and width of 1.0mm multiplied by 1.0mm by a cutting technology.

Example 2

Providing a double-sided polished double-sided unoxidized 6-inch monocrystalline silicon wafer with a 100 crystal orientation, then ultrasonically cleaning with acetone for 10min, ultrasonically cleaning with isopropanol for 10min, cleaning with deionized water for 5min, and drying with nitrogen; ceramic powder with proper specification is selected, an organic carrier is added to prepare ceramic slurry, the ceramic slurry is formed into a film on a wafer in a tape casting mode, and the film is dried for 10min at 150 ℃; placing the dried wafer into a muffle furnace, and sintering at 1000 ℃ for 30min to obtain a compact and hard ceramic film with the thickness of 20 um;

printing a heating resistor array and a heating electrode array with the length and width of 400um multiplied by 400um on a ceramic film in a screen printing mode, and a platinum thermal resistor temperature sensing film with the length and width of 1800um multiplied by 100um and a temperature sensing electrode with the length and width of 200um multiplied by 200um, drying at 130 ℃ for 5min, and sintering at 900 ℃ for 30min to obtain a heating electrode, a heating resistor, a temperature sensing electrode and a temperature sensing film; printing a tungsten oxide semiconductor gas-sensitive layer on the heating resistor layer by adopting a screen printing mode, drying for 5min at 120 ℃, and sintering for 10min at 850 ℃;

spin-coating positive photoresist on the back of a substrate, drying at 100 ℃ for 5min, performing patterned exposure and patterned development to obtain an unprotected region of the photoresist with the thickness of 15um and the length and width of 500um multiplied by 500um, removing silicon dioxide in the unprotected region by a reactive ion etching technology, etching the unprotected silicon of the photoresist by a deep silicon etching technology to form an adiabatic air cavity, and obtaining the hot wire type gas sensor chip with the length and width of 1.0mm multiplied by 1.0mm by a cutting technology.

Example 3

Providing a double-sided polished single-sided oxidized 2-inch monocrystalline silicon wafer with a 100 crystal orientation, then ultrasonically cleaning with acetone for 10min, ultrasonically cleaning with isopropanol for 10min, cleaning with deionized water for 5min, and drying with nitrogen; selecting ceramic powder with proper specification, adding an organic carrier, preparing ceramic slurry, forming a film on the unoxidized surface of a wafer by adopting a doctor blade method, and drying for 10min at 100 ℃; placing the dried wafer into a muffle furnace, and sintering for 30min at 1200 ℃ to obtain a compact and hard ceramic film with the thickness of 6 um;

printing a heating resistor array and a heating electrode array with the length and width of 500um multiplied by 500um on a ceramic film in a screen printing mode, and a gold-platinum thermocouple temperature sensing film with the length and width of 800um multiplied by 100um and a temperature sensing electrode with the length and width of 200um multiplied by 200um, drying at 150 ℃ for 5min, and sintering at 1000 ℃ for 10min to respectively obtain a heating electrode, a heating resistor, a temperature sensing electrode and a temperature sensing film; printing an indium oxide semiconductor gas-sensitive layer on a heating resistor by adopting a screen printing mode, drying at 150 ℃ for 5min, and sintering at 600 ℃ for 20min;

spin-coating negative photoresist on the back of a substrate, drying at 150 ℃ for 5min, performing patterned exposure and patterned development to obtain an unprotected region of the photoresist with the thickness of 25um and the length and width of 700um multiplied by 700um, removing silicon dioxide in the unprotected region by a reactive ion etching technology, etching the unprotected silicon of the photoresist by a deep silicon etching technology to form an adiabatic air cavity, and obtaining the hot wire type gas sensor chip with the length and width of 1.0mm multiplied by 1.0mm by a cutting technology.

Example 4

Providing a double-sided polished double-sided oxidized 8-inch monocrystalline silicon wafer with a 100 crystal orientation, then ultrasonically cleaning with acetone for 10min, ultrasonically cleaning with isopropanol for 5min, cleaning with deionized water for 5min, and drying with nitrogen; selecting ceramic powder with proper specification, adding an organic carrier, preparing ceramic slurry, forming a film on a wafer by adopting a screen printing mode, and drying for 10min at 150 ℃; placing the dried wafer into a muffle furnace, and sintering at 1200 ℃ for 60min to obtain a dense and hard ceramic film with the thickness of 8 um;

printing a heating resistor array and a heating electrode array with the length and the width of 500um multiplied by 500um on a ceramic film in a screen printing mode, and respectively obtaining a heating electrode, a heating resistor, a temperature sensing electrode and a temperature sensing film by 800um multiplied by 100um on a PTC thermistor temperature sensing film with the length and the width of 800um multiplied by 100um, drying at 150 ℃ for 5min and sintering at 1100 ℃ for 10min; printing a zinc oxide semiconductor gas-sensitive material layer on a heating resistor by adopting a screen printing mode, drying at 120 ℃ for 5min, and sintering at 850 ℃ for 20min;

spin-coating positive photoresist on the back of a substrate, drying at 150 ℃ for 5min, performing patterned exposure and patterned development to obtain an unprotected region of the photoresist with the thickness of 10um and the length and width of 800um multiplied by 800um, removing silicon dioxide in the unprotected region by a reactive ion etching technology, etching the unprotected silicon of the photoresist by a deep silicon etching technology to form an adiabatic air cavity, and obtaining the hot wire type gas sensor chip with the length and width of 1.5mm multiplied by 1.5mm by a cutting technology.

Example 5

Providing a double-sided polished double-sided unoxidized 12-inch monocrystalline silicon wafer with a 100 crystal orientation, then ultrasonically cleaning with acetone for 10min, ultrasonically cleaning with isopropanol for 5min, cleaning with deionized water for 5min, and blow-drying with nitrogen; selecting ceramic powder with proper specification, adding an organic carrier, preparing ceramic slurry, dividing the ceramic slurry into four mutually-spaced quadrant regions by taking the center of a wafer as the center, forming a film on the wafer by adopting a gravure printing mode, and drying the film for 10min at 150 ℃; placing the dried wafer into a muffle furnace, and sintering for 20min at 1300 ℃ to obtain a dense and hard ceramic film with the thickness of 25 um;

printing a heating resistor array with the length and the width of 300um multiplied by 300um and a heating electrode array on a ceramic film in a screen printing mode, and respectively obtaining a heating electrode, a heating resistor, a temperature sensing electrode and a temperature sensing film by 10 pairs of nickel-chromium-nickel-silicon thermocouple with the length and the width of 200um multiplied by 100um and a temperature sensing electrode with the length and the width of 100um multiplied by 100um by drying at 130 ℃ for 5min and sintering at 800 ℃ for 60 min; printing a semiconductor gas-sensitive material layer mixed by tungsten oxide and tin dioxide on a heating resistor by adopting a screen printing mode, drying for 5min at 150 ℃, and sintering for 20min at 800 ℃;

spin-coating positive photoresist on the back of a substrate, drying at 150 ℃ for 5min, performing patterned exposure and patterned development to obtain an unprotected region of the photoresist with the thickness of 12um and the length and width of 600um multiplied by 600um, removing silicon dioxide in the unprotected region by a reactive ion etching technology, etching the unprotected silicon of the photoresist by a deep silicon etching technology to form an adiabatic air cavity, and obtaining the hot wire type gas sensor chip with the length and width of 1.5mm multiplied by 1.5mm by a cutting technology.

Example 6

Providing a double-sided polished double-sided oxidized 10-inch monocrystalline silicon wafer with a 111 crystal orientation, then ultrasonically cleaning with acetone for 10min, ultrasonically cleaning with isopropanol for 5min, cleaning with deionized water for 5min, and drying with nitrogen; selecting ceramic powder with proper specification, adding an organic carrier, preparing ceramic slurry, dividing the ceramic slurry into 16 mutually-spaced areas by taking the center of a wafer as the center, forming a film on the wafer by adopting a screen printing mode, and drying the film for 10min at 150 ℃; placing the dried wafer into a muffle furnace, and sintering for 20min at 1100 ℃ to obtain a compact and hard ceramic film with the thickness of 15 um;

printing a rectangular heating resistor array and a heating electrode array with the length and width of 500um multiplied by 400um on a ceramic film in a screen printing mode, and respectively obtaining a heating electrode, a heating resistor, a temperature sensing electrode and a temperature sensing film by 5 pairs of platinum-rhodium thermocouples with the length and width of 300um multiplied by 100um and a temperature sensing electrode with the length and width of 100um multiplied by 100um by 5 pairs of platinum-rhodium thermocouples with the length and width of 100um multiplied by 100um, drying at 150 ℃ for 5min, and sintering at 850 ℃ for 60 min; printing a ceria semiconductor gas-sensitive material layer on the heating resistor by adopting a screen printing mode, drying at 150 ℃ for 5min, and sintering at 850 ℃ for 20min;

spin-coating positive photoresist on the back of a substrate, drying at 150 ℃ for 5min, performing patterned exposure and patterned development to obtain an unprotected region of the photoresist with the thickness of 8um and the length and width of 600um multiplied by 600um, removing silicon dioxide in the unprotected region by a reactive ion etching technology, etching the unprotected silicon of the photoresist by a deep silicon etching technology to form an adiabatic air cavity, and obtaining the hot wire type gas sensor chip with the length and width of 1.2mm multiplied by 1.2mm by a cutting technology.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims (10)

1. A hot wire gas sensor chip, comprising:

a substrate;

the gas sensing assembly comprises a heating electrode, a heating resistor and a semiconductor gas-sensitive layer, wherein the heating electrode and the heating resistor are arranged on the substrate, the heating resistor is electrically connected with the heating resistor, and the semiconductor gas-sensitive layer covers the heating resistor; a kind of electronic device with high-pressure air-conditioning system

The temperature sensing layer is arranged on the substrate and is positioned outside the area where the gas sensing component is positioned.

2. The hot wire gas sensor chip according to claim 1, wherein the temperature sensing layer includes a temperature sensing electrode and a temperature sensing film both disposed on the substrate, the temperature sensing electrode being electrically connected with the temperature sensing film.

3. The hot wire gas sensor chip according to claim 2, wherein the temperature sensing film has a width of 5 micrometers to 100 micrometers and a thickness of 0.1 micrometers to 20 micrometers.

4. The hot wire gas sensor chip of claim 2, wherein the temperature sensing film is disposed at least on one side of the gas sensing assembly or the temperature sensing film is disposed around the gas sensing assembly.

5. The hot wire gas sensor chip of claim 2, wherein the temperature sensing film is spaced from the region of the gas sensing assembly by a distance of 200-2000 microns.

6. The hot wire type gas sensor chip as claimed in claim 2, wherein the temperature sensing film is composed of one of PTC thermistor, NTC thermistor, thermal resistor, thermocouple.

7. The hot wire gas sensor chip as claimed in claim 1, wherein the substrate comprises a silicon substrate and a ceramic film disposed on the silicon substrate, and the heating electrode, the heating resistor and the temperature sensing layer are disposed on a surface of the ceramic film away from the silicon substrate.

8. The hot wire gas sensor chip as claimed in claim 7, wherein the ceramic film has a thickness of 1 to 50 μm.

9. The hot wire gas sensor chip as claimed in claim 7, wherein the silicon substrate comprises a first surface and a second surface opposite to the first surface, the ceramic film is disposed on the second surface, the silicon substrate comprises a heating zone at the center and a supporting zone disposed around the heating zone, the heating zone has a heat-insulating air cavity penetrating through the first surface and the second surface, and the heating resistor is disposed at a position corresponding to the heating zone on the ceramic film.

10. A hot wire gas sensor, characterized by comprising the hot wire gas sensor chip according to any one of claims 1-9, and further comprising a package housing, wherein the hot wire gas sensor chip is disposed in the package housing, a pin is disposed on the package housing, and the heating electrode is electrically connected with the pin.

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