Surface-mounted hygristor sensor
By designing a chip-type humidity-sensitive resistor sensor, the application difficulties of plug-in sensors in integrated and miniaturized scenarios are solved, miniaturization and automated production are achieved, costs are reduced, and accurate humidity testing capabilities are provided.
Patent Information
- Application Number
- CN202422672023.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-04
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-11-04
AI Technical Summary
Existing plug-in humidity-sensitive resistor sensors are large in size, difficult to apply to integrated and miniaturized scenarios, and have difficulties in automated production, resulting in inconvenient application and increased costs.
A patch-type humidity-sensitive resistor sensor is designed. It uses a 3mm*2mm square substrate, processes electrodes through a semiconductor etching process, and coats a polymer humidity-sensitive film on the substrate. It is suitable for 8-inch wafers and combines SiO2 and SiN insulating layers. The electrode materials can be selected from copper, aluminum, tungsten, titanium, gold, silver, nickel or platinum to achieve miniaturization and automated production.
The miniaturization of the sensor is achieved, which is suitable for integrated circuits, reduces the cost of automated production, and provides precise humidity testing through polymer humidity-sensing film, making it suitable for large-scale production.
Smart Images
Figure CN223485904U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of sensor technology, specifically to a patch-type humidity-sensitive resistor sensor. Background Art
[0002] Humidity is the moisture content in the air, a constantly changing equilibrium value. It is invisible and intangible, but it is an indispensable variable in our environment, affecting the growth and survival of all things.
[0003] Humidity sensors are a type of sensor that measures the humidity in the air, converting it into a measurable and readable physical quantity. Among them, the humidity-sensitive resistor sensor is currently the most widely used type of humidity sensor. It converts humidity variables into resistance changes and is widely used in furniture and appliances, industrial production, and agricultural production.
[0004] Currently, most humidity sensors sold on the market are plug-in type, which are simple to manufacture and very versatile. However, plug-in humidity sensors are relatively large and difficult to integrate into miniaturized applications. Furthermore, due to their structure, they are difficult to use in automated production of SMT or bonding equipment, resulting in inconvenience and increased costs for customers.
[0005] Based on the above problems, there is an urgent need for a humidity sensor that can be applied to integrated and miniaturized scenarios. Utility Model Content
[0006] To address the difficulty of applying current humidity-sensitive resistor sensors to integrated and miniaturized applications, this application provides a surface-mount humidity-sensitive resistor sensor to solve the aforementioned problem.
[0007] To achieve the above objectives, this utility model provides the following technical solution:
[0008] This application discloses a patch-type humidity-sensitive resistor sensor, comprising: a substrate, electrodes, and a polymer humidity-sensitive film. The substrate is square with a length and width of 3mm and 2mm, respectively. The electrodes are fabricated on the substrate using a semiconductor etching process. Each electrode includes vertical electrodes on both sides and circular interdigitated electrodes connected to the two vertical electrodes on both sides. The circular interdigitated electrodes are composed of a first electrode and a second electrode. The first electrode is composed of three ring electrodes fixedly connected to each other from the inside out, with a notch on one side of the two outer ring electrodes. The second electrode is composed of two ring electrodes with a notch on one side from the inside out. The two ring electrodes of the second electrode and the three ring electrodes of the first electrode are nested together. The polymer humidity-sensitive film is coated on the circular interdigitated electrodes.
[0009] Optionally, the substrate is an 8-inch wafer.
[0010] Optionally, an insulating layer is provided on the surface of the wafer, the insulating layer being made of SiO2 and / or SiN.
[0011] Optionally, the number of insulating layers is ≥1.
[0012] Optionally, the thickness of the insulating layer is 100-1000 nm.
[0013] Optionally, the electrode may be made of copper, aluminum, tungsten, titanium, gold, silver, nickel, or platinum.
[0014] Optionally, the two vertical electrodes are used for electrical connection to an external circuit.
[0015] Technical effects:
[0016] The humidity sensor provided in this application is only 2mm in size. With a thickness of 3mm and a small area, it is easy for customers to integrate it into circuits to meet miniaturization requirements; moreover, the surface mount technology allows customers to use mechanical equipment for automated production during application, reducing application costs. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the surface mount humidity sensor structure of this application;
[0019] Figure 2 This is a schematic diagram of the plug-in humidity sensor structure of this application.
[0020] In the picture:
[0021] 1. Substrate; 2. Electrode; 3. Polymer moisture-sensitive film; 4. Vertical electrode; 5. Circular interdigitated electrode; 6. First electrode; 7. Second electrode; 8. Insulating layer. DETAILED DESCRIPTION
[0022] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.
[0023] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.
[0024] Please see Figures 1-2Traditional humidity sensors, such as those with large size, are difficult to integrate and miniaturize. Furthermore, due to their structure, they are challenging for automated production in SMT or bonding equipment, leading to inconvenience and increased costs. To address these issues, this application discloses a surface-mount humidity sensor comprising a substrate, electrodes, and a polymer humidity-sensitive film. The substrate is a square with a length and width of 3mm and 2mm respectively, offering a small area for easy integration into circuits and miniaturization. The surface-mount design allows for automated production using mechanical equipment, reducing application costs. The electrodes are fabricated on the substrate using semiconductor etching. Each electrode includes two vertical electrodes on either side and circular interdigitated electrodes connected to the two vertical electrodes. The circular interdigitated electrodes consist of a first electrode and a second electrode. The first electrode has a shape consisting of three electrodes fixedly connected from the inside out. The first electrode consists of two ring electrodes, with notches on one side of the two outer ring electrodes. The second electrode consists of two ring electrodes with notches on one side, arranged from the inside out. The two ring electrodes of the second electrode and the three ring electrodes of the first electrode are nested together. The polymer humidity-sensitive film is coated on the circular interdigitated electrodes. It is worth mentioning that the technical solution provided in the above embodiment integrates the size to 2mm*3mm while satisfying the basic structure of the substrate, electrodes and polymer humidity-sensitive film. It can accurately measure the humidity change in the air. In order to meet the needs of mass production, our surface-mount humidity-sensitive resistor sensor is manufactured using 8-inch semiconductor technology. On the one hand, the technology is mature, suitable for large-scale measurement range, and low cost; on the other hand, the semiconductor process has high precision control, small error, good consistency of the produced sensors, small differences between individuals, and easy to replace each other, plug and play. This humidity-sensitive resistor sensor is directly processed into the electrode pattern shown in the figure through semiconductor etching process. The electrodes can be divided into two parts according to their function requirements: 1. Arc-shaped interdigitated electrodes, which are mainly connected to the polymer moisture-sensing membrane and belong to the moisture-sensing part; 2. Two vertical electrodes are the output terminals of the sensor, which are rectangular pads. The sensor can be connected to the external circuit through bonding or SMT bonding processes.
[0025] Considering the convenience of semiconductor processes, we chose silicon wafers as the substrate, which are commonly available in sizes of 4 inches, 6 inches, 8 inches and 12 inches. Considering the current state of equipment in the domestic semiconductor industry and the cost of our sensors, we chose 8-inch wafers; therefore, the substrate is an 8-inch wafer.
[0026] Silicon wafers themselves have poor insulation and are somewhat conductive. Since our sensor measures humidity using resistance, the silicon wafer itself can interfere with the measurement. Therefore, before fabricating the electrodes, an insulating layer is grown on the surface of the silicon wafer. We choose one or more insulating materials, such as SiO2 and SiN. The insulating layer can be one or more layers, with a thickness of 100-1000 nm, to achieve the desired insulation effect. An insulating layer is formed on the surface of the wafer, and the material of the insulating layer includes SiO2 and / or SiN. The number of insulating layers is ≥1, and the thickness of the insulating layer is 100-1000 nm.
[0027] We use metallic materials for the electrodes, requiring them to have good conductivity and stability, and to be insensitive to temperature and humidity. We select one or more of the following: copper, aluminum, tungsten, titanium, gold, silver, nickel, and platinum. The electrode material is copper, aluminum, tungsten, titanium, gold, silver, nickel, or platinum.
[0028] The two vertical electrodes are used for electrical connection to an external circuit.
[0029] It is worth mentioning that the sensitive material of our humidity-sensitive resistor sensor is a polymer material, which is a self-made polymer humidity-sensitive material solution. It is coated on the circular interdigital electrodes, completely covering the interdigital electrodes and penetrating into the gaps between the interdigital electrodes; but it cannot touch the electrode pads to prevent affecting the bonding or adhesion of the sensor to external circuits during application; finally, it is cured into a polymer humidity-sensitive film.
[0030] For ease of application, the center resistance of our surface-mount humidity sensor (resistance at 25℃ / 60%RH) is between 20-80kΩ, and the corresponding resistance variation can reach 104kΩ in the humidity range of 10-95%RH. It has sufficient humidity sensitivity and can accurately measure changes in humidity in the air.
[0031] Unless otherwise specified, the equipment components involved in the above embodiments are all conventional equipment components, and the connection methods and control methods involved are all conventional connection methods and control methods unless otherwise specified.
[0032] The present invention has been described in detail above with reference to the embodiments. However, those skilled in the art will understand that, without departing from the spirit of the present invention, various specific parameters in the above embodiments can be changed to form multiple specific embodiments, all of which are common variations of the present invention, and will not be described in detail here.
Claims
1. A surface-mount humidity sensor, characterized in that, include: The substrate, electrodes, and a polymer moisture-sensitive film are provided. The substrate is square with a length and width of 3 mm and 2 mm, respectively. The electrodes are fabricated on the substrate using a semiconductor etching process. Each electrode includes two vertical electrodes on both sides and circular interdigitated electrodes connected to the two vertical electrodes on both sides. The circular interdigitated electrodes consist of a first electrode and a second electrode. The first electrode is composed of three ring electrodes fixedly connected to each other from the inside out, with a notch on one side of the two outer ring electrodes. The second electrode is composed of two ring electrodes with a notch on one side from the inside out. The two ring electrodes of the second electrode and the three ring electrodes of the first electrode are nested together. The polymer moisture-sensitive film is coated on the circular interdigitated electrodes.
2. The patch-type humidity sensor according to claim 1, characterized in that, The substrate is an 8-inch wafer.
3. A patch-type humidity sensor according to claim 2, characterized in that, An insulating layer is disposed on the surface of the wafer, and the insulating layer is made of SiO2 and / or SiN.
4. A patch-type humidity sensor according to claim 3, characterized in that, The number of insulating layers is ≥1.
5. A patch-type humidity sensor according to claim 3, characterized in that, The thickness of the insulating layer is 100-1000 nm.
6. A patch-type humidity sensor according to claim 1, characterized in that, The electrode is made of copper, aluminum, tungsten, titanium, gold, silver, nickel, or platinum.
7. A patch-type humidity sensor according to claim 1, characterized in that, The two vertical electrodes are used for electrical connection to an external circuit.