Sensor chip structure, sensor chip preparation method and gas sensor

Abstract

Provided in the present invention are a gas sensor chip structure, a sensor chip preparation method and a gas sensor. The structure comprises a substrate, an electrode assembly and a gas-sensitive film, wherein the electrode assembly comprises a first interdigital electrode and a second interdigital electrode, which are both arranged on the substrate, and there is a level difference between the first interdigital electrode and the second interdigital electrode; and the gas-sensitive film is arranged between the first interdigital electrode and the second interdigital electrode. Thus, the connection stability of the first interdigital electrode and the second interdigital electrode can be improved while ensuring that the gas-sensitive film is maintained at a relatively small volume, the difficulty in controlling the thickness of the gas-sensitive film can be reduced, and the response speed can also be improved.

Description

Sensor chip structure, sensor chip preparation method and gas sensor TECHNICAL FIELD

[0001] The present application belongs to the field of intelligent sensing technology, and particularly relates to a gas sensor chip structure, a sensor chip preparation method and a gas sensor. BACKGROUND

[0002] A gas sensor is a kind of converter that converts the volume fraction of a certain gas into a corresponding electrical signal, and is commonly used for detecting whether a specific gas exists in a certain area and / or continuously measuring the concentration of a gas component, such as CO, NH3, NO2, etc.

[0003] A fork electrode gas concentration sensor is a common type of sensor that uses a fork electrode to detect the concentration of a specific gas. The fork electrode is usually composed of two or more conductive fingers that are arranged opposite to each other and cross each other to form a conductive grid. When the gas contacts the electrode grid, it changes the capacitance or resistance between the electrodes. According to the capacitance difference or resistance difference, the signal conversion circuit of the sensor can calculate the relevant gas concentration parameter.

[0004] In order to improve the measurement accuracy of the gas concentration sensor, in the prior art, a gas sensitive film is added to the fork electrode of the gas concentration sensor, the conductive fingers of the fork electrode are inserted into the gas sensitive film to form a conductive path, and the resistance signal of the gas sensitive film is fed back to the central control system through the signal conversion circuit. When the gas contacts the gas sensitive film, the resistance of the gas sensitive film changes, and the resistance difference is formed into a monitoring electrical signal output to the central control system through the signal conversion circuit, and the central control system detects the gas concentration according to the monitoring electrical signal.

[0005] However, in the conventional fork electrode gas sensor, all the conductive fingers in the fork electrode are arranged horizontally on the same horizontal plane, and the gas sensitive film is coated on the fork electrode by means of dispensing processing. The overall structure of the fork electrode and the gas sensitive film is in a spherical ball structure, which is not conducive to the spatial optimization efficiency of the gas sensor.

[0006] On the other hand, the gas contacts the surface layer of the gas sensitive film, and a local chemical reaction occurs, and then the overall resistance or capacitance changes to form a resistance difference or capacitance difference, which can be detected. Since the volume of the gas sensitive film is too large, it takes a long time from the contact between the gas to be detected and the gas sensitive film to the change of the physical properties of the gas sensitive film, resulting in a long response time of the sensor and a slow response speed of the entire gas concentration sensor, which needs to be improved. SUMMARY

[0007] In order to overcome the deficiencies of the prior art, the present application provides a gas sensor chip structure, a sensor chip preparation method and a gas sensor to solve the technical problems of the prior art that the volume of the gas sensitive film is too large, which affects the space optimization and causes slow response speed and low sensitivity of the sensor.

[0008] One of the embodiments of the present application provides a sensor chip structure, comprising a substrate, an electrode assembly and a gas sensitive film; the electrode assembly comprises a first fork-shaped electrode and a second fork-shaped electrode, both of which are arranged on the substrate, and there is a site difference between the first fork-shaped electrode and the second fork-shaped electrode; the gas sensitive film is arranged between the first fork-shaped electrode and the second fork-shaped electrode.

[0009] The sensor chip structure provided by the present application has at least the following beneficial effects: by arranging the first fork-shaped electrode and the second fork-shaped electrode with a site difference on the substrate, and arranging the gas sensitive film between the first fork-shaped electrode and the second fork-shaped electrode, the connection stability of the first fork-shaped electrode and the second fork-shaped electrode can be improved under the premise that the gas sensitive film maintains a small volume, the thickness control difficulty of the gas sensitive film is reduced, and the response speed is improved.

[0010] Optionally, the first fork-shaped electrode is arranged on the substrate, and an insulating isolation layer is arranged on the substrate, the insulating isolation layer is matched with the conductive finger shape of the first fork-shaped electrode, the end of the insulating isolation layer can extend into the gap between any two adjacent groups of conductive fingers of the first fork-shaped electrode, the insulating isolation layer and the first fork-shaped electrode as a whole are arranged in a support plate structure parallel to the top surface of the substrate, the gas sensitive film is formed on the insulating isolation layer and the first fork-shaped electrode, and the second fork-shaped electrode is formed on the insulating isolation layer.

[0011] By extending the end of the first insulating isolation layer to the gap between the conductive fingers of the first fork-shaped electrode, and arranging the first fork-shaped electrode and the first insulating isolation layer as a whole in a flat plate structure on the substrate, the gas sensitive film is formed on the first fork-shaped electrode and the first insulating isolation layer, and the second fork-shaped electrode is formed on the insulating isolation layer, so as to improve the compactness and stability of the overall structure, improve the preparation efficiency, and prolong the service life.

[0012] Optionally, the conductive fingers of the second fork-shaped electrode are arranged in a staggered manner with the conductive fingers of the first fork-shaped electrode.

[0013] By arranging the conductive fingers of the first fork-shaped electrode and the second fork-shaped electrode in a staggered manner, the area difference between the gas sensitive film and the electrode is greatly reduced, and the detection sensitivity of the gas sensor is improved.

[0014] Optionally, the first fork-shaped electrode is arranged on the substrate, the gas sensitive film is arranged along the conductive finger arrangement path of the first fork-shaped electrode, the substrate is provided with an insulating isolation layer, the insulating isolation layer is arranged on one side of the conductive finger of the first fork-shaped electrode, the body of the second fork-shaped electrode is arranged on the insulating isolation layer, and the conductive finger of the second fork-shaped electrode is arranged on the gas sensitive film, wherein the conductive fingers of the first fork-shaped electrode and the second fork-shaped electrode are arranged in a staggered manner, the gas sensitive film is formed by bending and extending to have a plurality of grooves for respectively accommodating the conductive fingers of the first fork-shaped electrode and the second fork-shaped electrode.

[0015] By arranging the first fork-shaped electrode on the substrate, the gas sensitive film is arranged along the conductive finger arrangement path of the first fork-shaped electrode, and the substrate is provided with an insulating isolation layer. By arranging the insulating isolation layer on one side of the conductive finger of the first fork-shaped electrode, arranging the body of the second fork-shaped electrode on the insulating isolation layer, and arranging the conductive finger of the second fork-shaped electrode on the gas sensitive film, the conductive fingers of the first fork-shaped electrode and the second fork-shaped electrode are arranged in a staggered manner, thereby improving the compactness of the overall structure. By bending and extending the gas sensitive film to have a plurality of grooves for respectively accommodating the conductive fingers of the first fork-shaped electrode and the second fork-shaped electrode, the overall structural layout effect is further optimized, and the overall strength and compactness are improved.

[0016] Optionally, the thicknesses of the conductive finger of the first fork-shaped electrode, the gas sensitive film, and the insulating isolation layer are the same, and the groove bottom wall of the gas sensitive film close to the insulating isolation layer is arranged flush with the top surface of the insulating isolation layer.

[0017] Since the thicknesses of the conductive finger of the first fork-shaped electrode, the gas sensitive film, and the insulating isolation layer are the same, by arranging the groove bottom wall of the gas sensitive film close to the insulating isolation layer flush with the top surface of the insulating isolation layer, the body and the conductive finger of the second fork-shaped electrode are horizontally extended, thereby strengthening the stability of the overall structure.

[0018] Optionally, the substrate is formed with a groove, the insulating isolation layer covers the groove formed on the substrate, and the two ends of the groove formed on the substrate respectively extend to below the conductive finger of the first fork-shaped electrode and to one side of the insulating isolation layer away from the first fork-shaped electrode. The sensor chip structure further includes a conductive wire, the conductive wire is arranged in the groove formed on the substrate, the two ends of the conductive wire extend from the center position of the groove formed on the substrate to the two ends and are respectively electrically connected with the conductive finger of the first fork-shaped electrode and an external heating circuit, and the body of the first fork-shaped electrode is electrically connected with the external heating circuit, so that the first fork-shaped electrode becomes a heating load of the external heating circuit.

[0019] The conductive wire is integrated on the first fork-shaped electrode by embedding the conductive wire in the groove formed on the substrate and electrically connecting the two ends of the conductive wire with the conductive clamps in the first fork-shaped electrode to an external heating circuit, and the body of the first fork-shaped electrode is electrically connected with the external heating circuit, so that the first fork-shaped electrode becomes a heating load of the external heating circuit, thereby realizing the heating function and improving the device integration.

[0020] Optionally, the number of the groove formed on the substrate and the conductive wire is at least one set, all the grooves formed on the substrate are arranged at intervals along the arrangement direction of the conductive clamps of the first fork-shaped electrode, all the conductive wires are arranged in the corresponding grooves formed on the substrate one by one, and all the conductive wires are connected in parallel on the external heating circuit.

[0021] By arranging multiple sets of conductive wires and corresponding grooves, the heating effect of the first fork-shaped electrode is improved.

[0022] The sensor chip structure is used in a gas sensor.

[0023] The present application provides a sensor chip preparation method, comprising the following steps:

[0024] A metal thin film is deposited on the substrate along a preset path to form a first fork-shaped electrode;

[0025] An insulating isolation layer with a thickness equal to that of the first fork-shaped electrode is deposited on the end of the substrate on one side of the first fork-shaped electrode, so that the first fork-shaped electrode and the insulating isolation layer form a support plate-shaped structure parallel to the top surface of the substrate;

[0026] A gas-sensitive film is deposited on the whole structure formed by the first fork-shaped electrode and the insulating isolation layer;

[0027] A metal thin film is deposited on the gas-sensitive film along a preset path to form a second fork-shaped electrode.

[0028] The sensor chip structure is prepared by using the sensor chip preparation method, the metal thin film is deposited along the preset path on the substrate to form the first fork-shaped electrode, the insulating isolation layer with the same thickness as the first fork-shaped electrode is deposited on the end of the substrate on the side of the first fork-shaped electrode, so that the first fork-shaped electrode and the insulating isolation layer form a support plate-shaped structure parallel to the top surface of the substrate, the gas sensitive film is deposited on the whole structure formed by the first fork-shaped electrode and the insulating isolation layer, then the metal thin film is deposited along the preset path on the gas sensitive film to form the second fork-shaped electrode; the connection stability of the first fork-shaped electrode and the second fork-shaped electrode is improved under the premise that the gas sensitive film maintains a small volume, the thickness control difficulty of the gas sensitive film is reduced, the response speed is improved, the first fork-shaped electrode and the first insulating isolation layer are in the form of a flat plate structure and are laid on the substrate, so that the gas sensitive film is formed on the first fork-shaped electrode and the first insulating isolation layer, the second fork-shaped electrode is formed on the insulating isolation layer, the compactness and stability of the whole structure are improved, the preparation efficiency is improved, and the service life is prolonged.

[0029] The application provides a sensor chip preparation method, which comprises the following steps:

[0030] The metal thin film is deposited along the preset path on the substrate to form the first fork-shaped electrode;

[0031] The gas sensitive film is deposited along the conductive finger arrangement direction of the first fork-shaped electrode, so that the groove structure is formed on the gas sensitive film;

[0032] The insulating isolation layer with the same thickness as the gas sensitive film is deposited on the end of the substrate away from the body of the first fork-shaped electrode along the preset path;

[0033] The metal thin film is deposited on the insulating isolation layer along the preset path to form the body of the second fork-shaped electrode;

[0034] The metal thin film is deposited on the gas sensitive film along the preset path to form the conductive finger of the second fork-shaped electrode.

[0035] By using the sensor chip preparation method to prepare the sensor chip structure as above, the first interdigital electrode is formed by depositing a metal thin film along a preset path on the substrate, and the gas sensitive film is deposited along the arrangement direction of the conductive fingers of the first interdigital electrode, so that the recess structure is formed on the gas sensitive film, after the insulating isolation layer with a thickness equal to that of the gas sensitive film is deposited on the substrate at the end of the gas sensitive film away from the body of the first interdigital electrode along a preset path, the body of the second interdigital electrode is formed by depositing a metal thin film on the insulating isolation layer along a preset path; and the conductive fingers of the second interdigital electrode are formed by depositing a metal thin film on the gas sensitive film along a preset path; the connection stability of the first interdigital electrode and the second interdigital electrode can be improved under the premise of maintaining a small volume of the gas sensitive film, the thickness control difficulty of the gas sensitive film is reduced, and the response speed is improved; by arranging the first interdigital electrode on the substrate, the gas sensitive film is formed along the arrangement path of the conductive fingers of the first interdigital electrode, and the insulating isolation layer is arranged on the substrate, the body of the second interdigital electrode is arranged on the insulating isolation layer, the conductive fingers of the second interdigital electrode are arranged on the gas sensitive film, and the gas sensitive film is formed by bending and extending to have a plurality of recesses for accommodating the conductive fingers of the first interdigital electrode and the second interdigital electrode, respectively, thereby further optimizing the overall structural layout effect and improving the overall strength and compactness. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. 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 based on the drawings shown.

[0037] Fig. 1 is a structural schematic diagram of a sensor chip structure provided by an embodiment of the present application;

[0038] Fig. 2 is a schematic diagram of the cross-sectional structure of the sensor chip structure in Fig. 1;

[0039] Fig. 3 is a schematic diagram of the cross-sectional structure of the sensor chip structure in Fig. 1 from another direction;

[0040] Fig. 4 is a structural schematic diagram of a sensor chip structure provided by an embodiment of the present application;

[0041] Fig. 5 is a schematic diagram of the cross-sectional structure of the sensor chip structure in Fig. 4;

[0042] Fig. 6 is an exploded view of the sensor chip structure in Fig. 4;

[0043] Fig. 7 is a structural schematic diagram of a sensor chip structure according to another embodiment of the present application;

[0044] Fig. 8 is an exploded view of the sensor chip structure in Fig. 7;

[0045] Fig. 9 is a perspective view of the sensor chip structure in Fig. 7.

[0046] BRIEF DESCRIPTION OF DRAWINGS: 1, substrate, 2, electrode assembly, 21, first fork electrode, 22, second fork electrode, 23, conductive finger, 3, gas sensitive membrane, 4, insulating isolation layer, 5, conductive wire. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0048] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0049] In addition, if the embodiments of the present application involve descriptions of "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, "and / or" or "and / or" appearing throughout the text means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B are satisfied at the same time. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of a person skilled in the art, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.

[0050] Referring to FIGS. 1-9, one embodiment of the present application provides a sensor chip structure, which comprises a substrate 1, an electrode assembly 2 and a gas sensitive film 3; the electrode assembly 2 comprises a first fork-shaped electrode 21 and a second fork-shaped electrode 22, the first fork-shaped electrode 21 and the second fork-shaped electrode 22 are both arranged on the substrate 1, and there is a site difference between the first fork-shaped electrode 21 and the second fork-shaped electrode 22; the gas sensitive film 3 is arranged between the first fork-shaped electrode 21 and the second fork-shaped electrode 22.

[0051] In the embodiment, the sensor chip structure provided by the present application has at least the following beneficial effects: by arranging the first fork-shaped electrode 21 and the second fork-shaped electrode 22 with a site difference on the substrate 1 and arranging the gas sensitive film 3 between the first fork-shaped electrode 21 and the second fork-shaped electrode 22, the connection stability of the first fork-shaped electrode 21 and the second fork-shaped electrode 22 can be improved under the premise that the gas sensitive film 3 maintains a small volume, the thickness control difficulty of the gas sensitive film 3 is reduced, and the response speed is improved.

[0052] Referring to FIGS. 7-9, in one embodiment, the first fork-shaped electrode 21 is arranged on the substrate 1, the substrate 1 is provided with an insulating isolation layer 4, the insulating isolation layer 4 is matched with the shape of the conductive fingers 23 of the first fork-shaped electrode 21, the end of the insulating isolation layer 4 can extend into the gap between any two adjacent groups of conductive fingers 23 of the first fork-shaped electrode 21, so that the insulating isolation layer 4 and the first fork-shaped electrode 21 form a support plate structure parallel to the top surface of the substrate 1, the gas sensitive film 3 is formed on the insulating isolation layer 4 and the first fork-shaped electrode 21, and the second fork-shaped electrode 22 is formed on the insulating isolation layer 4.

[0053] In the embodiment, by extending the end of the insulating isolation layer 4 to the gap between the conductive fingers 23 of the first fork-shaped electrode 21, and arranging the first fork-shaped electrode 21 and the insulating isolation layer 4 in a flat plate structure on the substrate 1, the gas sensitive film 3 is formed on the first fork-shaped electrode 21 and the insulating isolation layer 4, and the second fork-shaped electrode 22 is formed on the insulating isolation layer 4, so as to improve the compactness and stability of the overall structure, improve the preparation efficiency, and prolong the service life.

[0054] Referring to FIGS. 7-9, in one embodiment, the conductive fingers 23 of the second fork-shaped electrode 22 are arranged in a staggered manner with the conductive fingers 23 of the first fork-shaped electrode 21.

[0055] In the embodiment, by arranging the conductive fingers 23 of the first fork-shaped electrode 21 and the second fork-shaped electrode 22 in a staggered manner, the area difference between the gas sensitive film 3 and the electrodes is greatly reduced, and the detection sensitivity of the gas sensor is improved.

[0056] Please refer to FIG. 1-6, in one embodiment, the first fork electrode 21 is arranged on the substrate 1, the gas sensitive film 3 is arranged along the conductive fingers 23 of the first fork electrode 21, the insulating isolation layer 4 is arranged on the substrate 1, the insulating isolation layer 4 is arranged on one side of the conductive fingers 23 of the first fork electrode 21, the body of the second fork electrode 22 is arranged on the insulating isolation layer 4, and the conductive fingers 23 of the second fork electrode 22 are arranged on the gas sensitive film 3, wherein the conductive fingers 23 of the first fork electrode 21 and the second fork electrode 22 are arranged in a staggered manner, and the gas sensitive film 3 is formed by bending and extending to have a plurality of grooves for respectively accommodating the conductive fingers 23 of the first fork electrode 21 and the second fork electrode 22.

[0057] In this embodiment, by arranging the first fork electrode 21 on the substrate 1, the gas sensitive film 3 is arranged along the conductive fingers 23 of the first fork electrode 21, and the insulating isolation layer 4 is arranged on the substrate 1, by arranging the insulating isolation layer 4 on one side of the conductive fingers 23 of the first fork electrode 21, arranging the body of the second fork electrode 22 on the insulating isolation layer 4, and arranging the conductive fingers 23 of the second fork electrode 22 on the gas sensitive film 3, by arranging the conductive fingers 23 of the first fork electrode 21 and the second fork electrode 22 in a staggered manner, the overall structure compactness is improved, and by bending and extending the gas sensitive film 3 to have a plurality of grooves for respectively accommodating the conductive fingers 23 of the first fork electrode 21 and the second fork electrode 22, the overall structure layout effect is further optimized, and the overall strength and compactness are improved.

[0058] Please refer to FIG. 1-6, in one embodiment, the thickness of the conductive fingers 23 of the first fork electrode 21, the gas sensitive film 3 and the insulating isolation layer 4 is the same, and the groove bottom wall of the gas sensitive film 3 close to the insulating isolation layer 4 is arranged flush with the top surface of the insulating isolation layer 4.

[0059] In this embodiment, since the thickness of the conductive fingers 23 of the first fork electrode 21, the gas sensitive film 3 and the insulating isolation layer 4 is the same, by arranging the groove bottom wall of the gas sensitive film 3 close to the insulating isolation layer 4 flush with the top surface of the insulating isolation layer 4, the body and the conductive fingers 23 of the second fork electrode 22 are horizontally extended, and the overall structure stability is strengthened.

[0060] Referring to FIGS. 1-3, in one embodiment, the substrate 1 is formed with a groove, the insulating isolation layer 4 covers the groove formed on the substrate, two ends of the groove formed on the substrate extend to below the conductive fingers 23 of the first fork-shaped electrode 21 and to the side of the insulating isolation layer 4 away from the first fork-shaped electrode 21, respectively, the sensor chip structure further comprises a conductive wire 5, the conductive wire 5 is laid in the groove formed on the substrate, two ends of the conductive wire 5 extend from the center of the groove formed on the substrate to both ends and are electrically connected with the conductive fingers 23 of the first fork-shaped electrode 21 and an external heating circuit, respectively, the body of the first fork-shaped electrode 21 is electrically connected with the external heating circuit, so that the first fork-shaped electrode 21 becomes a heating load of the external heating circuit.

[0061] In the embodiment, the conductive wire 5 is integrated on the first fork-shaped electrode 21 by embedding the conductive wire 5 in the groove formed on the substrate 1 and electrically connecting two ends of the conductive wire 5 with the conductive fingers 23 in the first fork-shaped electrode 21 and the external heating circuit, respectively, and the body of the first fork-shaped electrode 21 is electrically connected with the external heating circuit, so that the first fork-shaped electrode 21 becomes a heating load of the external heating circuit, thereby realizing the heating function and improving the device integration.

[0062] Referring to FIGS. 1-3, in one embodiment, the number of the groove formed on the substrate and the conductive wire 5 is at least one set, all the grooves formed on the substrate are arranged at intervals along the arrangement direction of the conductive fingers 23 of the first fork-shaped electrode 21, all the conductive wires 5 are arranged in the corresponding groove formed on the substrate one by one, and all the conductive wires 5 are connected in parallel on the external heating circuit.

[0063] In the embodiment, the heating effect of the first fork-shaped electrode 21 is improved by setting multiple sets of the conductive wire 5 and the corresponding groove.

[0064] Another embodiment of the present application further provides a gas sensor comprising the sensor chip structure according to any one of the above.

[0065] Referring to FIGS. 7-9, another embodiment of the present application further provides a sensor chip preparation method, comprising the following steps:

[0066] depositing a metal thin film on the substrate 1 along a preset path to form the first fork-shaped electrode 21;

[0067] depositing an insulating isolation layer 4 with a thickness equal to that of the first fork-shaped electrode 21 on the substrate 1 at the end of the side of the first fork-shaped electrode 21, so that the first fork-shaped electrode 21 and the insulating isolation layer 4 form a support plate-shaped structure parallel to the top surface of the substrate;

[0068] depositing a metal thin film on the gas sensitive film 3 along the preset path to form the second interdigital electrode 22.

[0069] depositing a metal thin film on the gas sensitive film 3 along the preset path to form the second interdigital electrode 22.

[0070] In the embodiment, the sensor chip structure is prepared by using the sensor chip preparation method, so that the flat gas sensitive film is prepared. Specifically, the first interdigital electrode 21 is formed by depositing a metal thin film on the substrate 1 along the preset path, and the insulating isolation layer 4 with the same thickness as the first interdigital electrode 21 is deposited on the end of the substrate 1 on the side of the first interdigital electrode 21, so that the first interdigital electrode 21 and the insulating isolation layer 4 form a support plate-shaped structure parallel to the top surface of the substrate. After the gas sensitive film 3 is deposited on the overall structure formed by the first interdigital electrode 21 and the insulating isolation layer 4, a metal thin film is deposited on the gas sensitive film 3 along the preset path to form the second interdigital electrode 22. The connection stability of the first interdigital electrode 21 and the second interdigital electrode 22 is improved under the premise that the gas sensitive film 3 maintains a small volume, the thickness control difficulty of the gas sensitive film 3 is reduced, the response speed is improved, the overall structure is compact and stable, the preparation efficiency is improved, and the service life is prolonged.

[0071] Referring to FIGS. 1-6, another embodiment of the present application further provides a sensor chip preparation method, comprising the following steps:

[0072] depositing a metal thin film on the substrate 1 along the preset path to form the first interdigital electrode 21;

[0073] depositing the gas sensitive film 3 along the arrangement direction of the conductive fingers 23 of the first interdigital electrode 21, so that the recess structure is formed on the gas sensitive film 3;

[0074] depositing the insulating isolation layer 4 with the same thickness as the gas sensitive film 3 on the end of the substrate 1 away from the body of the first interdigital electrode 21 along the preset path;

[0075] depositing a metal thin film on the insulating isolation layer 4 along the preset path to form the body of the second interdigital electrode 22;

[0076] depositing a metal thin film on the gas sensitive film 3 along the preset path to form the conductive fingers 23 of the second interdigital electrode 22.

[0077] In the embodiment, the sensor chip structure is prepared by using the sensor chip preparation method, so that the preparation of the bending type gas sensitive film is realized. Specifically, the first interdigital electrode 21 is formed by depositing a metal thin film on the substrate 1 along a preset path, and the gas sensitive film 3 is deposited along the arrangement direction of the conductive fingers 23 of the first interdigital electrode 21, so that the groove structure is formed on the gas sensitive film 3. After the insulating isolation layer 4 with a thickness equal to that of the gas sensitive film 3 is deposited on the substrate 1 at the end of the gas sensitive film 3 away from the body of the first interdigital electrode 21 along a preset path, the body of the second interdigital electrode 22 is formed by depositing a metal thin film on the insulating isolation layer 4 along a preset path. The conductive fingers 23 of the second interdigital electrode 22 are formed by depositing a metal thin film on the gas sensitive film 3 along a preset path. Under the premise of ensuring that the gas sensitive film 3 maintains a small volume, the connection stability of the first interdigital electrode 21 and the second interdigital electrode 22 is improved, the thickness control difficulty of the gas sensitive film 3 is reduced, and the response speed is improved. By arranging the first interdigital electrode 21 on the substrate 1, the gas sensitive film 3 is laid and formed along the arrangement path of the conductive fingers 23 of the first interdigital electrode 21, and the insulating isolation layer 4 is arranged on the substrate 1. The insulating isolation layer 4 is arranged on one side of the conductive fingers 23 of the first interdigital electrode 21, and the body of the second interdigital electrode 22 is arranged on the insulating isolation layer 4. The conductive fingers 23 of the second interdigital electrode 22 are arranged on the gas sensitive film 3. The gas sensitive film 3 is formed by bending and extending to have a plurality of grooves for respectively accommodating the conductive fingers 23 of the first interdigital electrode 21 and the second interdigital electrode 22, which further optimizes the overall structural layout effect and improves the overall strength and compactness.

[0078] The above description is only the preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation, direct / indirect application in other related technical fields based on the inventive concept of the present application and the content of the specification and drawings are included in the patent protection scope of the present application.

Claims

1. A sensor chip structure, characterized by The application relates to a gas sensor, which comprises the following components: a substrate; an electrode assembly, which comprises a first fork-shaped electrode and a second fork-shaped electrode, the first fork-shaped electrode and the second fork-shaped electrode are arranged on the substrate, and there is a bit plane difference between the first fork-shaped electrode and the second fork-shaped electrode; a gas sensitive film, which is arranged between the first fork-shaped electrode and the second fork-shaped electrode; and an insulating isolation layer, which is arranged on the substrate; wherein the gas sensitive film is formed on the insulating isolation layer and the first fork-shaped electrode, the second fork-shaped electrode is formed on the insulating isolation layer, or the insulating isolation layer is arranged on one side of the conductive clamping fingers of the first fork-shaped electrode, the body of the second fork-shaped electrode is arranged on the insulating isolation layer, and the conductive clamping fingers of the second fork-shaped electrode are arranged on the gas sensitive film, so as to form the bit plane difference; when the gas sensitive film is formed on the insulating isolation layer and the first fork-shaped electrode, and the second fork-shaped electrode is formed on the insulating isolation layer, the insulating isolation layer is matched with the shape of the conductive clamping fingers of the first fork-shaped electrode, the end of the insulating isolation layer can extend into the gap between any two adjacent groups of the conductive clamping fingers of the first fork-shaped electrode, and the insulating isolation layer and the first fork-shaped electrode are arranged in a supporting plate structure which is parallel to the top surface of the substrate; the gas sensitive film is deposited on the supporting plate structure formed by the first fork-shaped electrode and the insulating isolation layer, a metal thin film is deposited on the gas sensitive film along a preset path, and the second fork-shaped electrode is formed, the conductive clamping fingers of the second fork-shaped electrode are arranged in a staggered mode with the conductive clamping fingers of the first fork-shaped electrode; when the insulating isolation layer is arranged on one side of the conductive clamping fingers of the first fork-shaped electrode, the body of the second fork-shaped electrode is arranged on the insulating isolation layer, and the conductive clamping fingers of the second fork-shaped electrode are arranged on the gas sensitive film, the gas sensitive film is formed along the arrangement path of the conductive clamping fingers of the first fork-shaped electrode, the conductive clamping fingers of the first fork-shaped electrode and the second fork-shaped electrode are arranged in a staggered mode, the gas sensitive film is formed by bending and extending to have a plurality of grooves which respectively accommodate the conductive clamping fingers of the first fork-shaped electrode and the second fork-shaped electrode; an insulating isolation layer with a thickness equal to that of the gas sensitive film is deposited on the end of the substrate which is away from the body of the first fork-shaped electrode along a preset path, a metal thin film is deposited on the insulating isolation layer along a preset path, and the body of the second fork-shaped electrode is formed, a metal thin film is deposited on the gas sensitive film along a preset path, and the conductive clamping fingers of the second fork-shaped electrode are formed; the thicknesses of the conductive clamping fingers of the first fork-shaped electrode, the gas sensitive film and the insulating isolation layer are the same, and the bottom wall of the groove close to the insulating isolation layer on the gas sensitive film is arranged in a flush mode with the top surface of the insulating isolation layer. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2. The sensor chip structure according to claim 1, characterized in that: The base is formed with a groove, the insulating isolation layer covers the groove formed on the base, two ends of the groove formed on the base respectively extend to below the conductive fingers of the first fork-shaped electrode and to the side of the insulating isolation layer away from the first fork-shaped electrode, the sensor chip structure further comprises a conductive wire, the conductive wire is laid in the groove formed on the base, two ends of the conductive wire extend from the center of the groove formed on the base to both ends and are respectively electrically connected with the conductive fingers of the first fork-shaped electrode and the external heating circuit, the body of the first fork-shaped electrode is electrically connected with the external heating circuit, so that the first fork-shaped electrode becomes a heating load of the external heating circuit.

3. The sensor chip structure according to claim 2, characterized in that: The number of the groove formed on the base and the conductive wire is at least one group, all the grooves formed on the base are arranged at intervals along the arrangement direction of the conductive fingers of the first fork-shaped electrode, all the conductive wires are respectively arranged in the corresponding groove formed on the base, and all the conductive wires are connected in parallel on the external heating circuit.

4. A gas sensor characterized by: The sensor chip structure comprises the sensor chip structure according to any one of claims 1-3.

5. A method for manufacturing a sensor chip for use in the sensor chip structure according to any one of claims 1 to 3, characterized by, The method comprises the following steps: depositing a metal thin film on the base along a preset path to form a first fork-shaped electrode; depositing an insulating isolation layer with a thickness equal to that of the first fork-shaped electrode on the end of the base on one side of the first fork-shaped electrode, so that the first fork-shaped electrode and the insulating isolation layer form a support plate-shaped structure parallel to the top surface of the base; depositing a gas-sensitive film on the support plate-shaped structure formed by the first fork-shaped electrode and the insulating isolation layer; depositing a metal thin film on the gas-sensitive film along a preset path to form a second fork-shaped electrode Alternatively, the method comprises the following steps: depositing a metal thin film on the base along a preset path to form a first fork-shaped electrode; depositing a gas-sensitive film along the arrangement direction of the conductive fingers of the first fork-shaped electrode, so that a groove structure is formed on the gas-sensitive film; depositing an insulating isolation layer with a thickness equal to that of the gas-sensitive film on the end of the base away from the body of the first fork-shaped electrode along a preset path; depositing a metal thin film on the insulating isolation layer along a preset path to form the body of a second fork-shaped electrode; depositing a metal thin film on the gas-sensitive film along a preset path to form the conductive fingers of the second fork-shaped electrode.

Images