Flexible temperature sensor manufacturing method

Abstract

The invention provides a manufacturing method of a flexible temperature sensor, which comprises the following steps that: a required temperature sensor pattern is prepared on photoresist by utilizing a photoetching process to serve as a mask for manufacturing the flexible temperature sensor, and the edge of the mask forming the required pattern shape is of an inverted trapezoidal structure; stripping the mask, transferring and fixing the mask on the lower surface of the etched electrode pattern screen; preparing a carbon electrode on the flexible substrate by utilizing silk-screen printing; manufacturing a temperature-sensitive material and a screen engraved with a temperature-sensitive layer pattern; a temperature sensitive layer made of a temperature sensitive material is prepared on a flexible substrate by utilizing laminated screen printing, so that a complete temperature sensor is obtained. The mask of the inverted trapezoidal structure is used for promoting ink separation, so that the precision of the island bridge structure is improved, the piezoresistive response of the temperature sensor is reduced, and the measurement precision of the temperature sensor is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible temperature sensor manufacturing, and particularly relates to a method for manufacturing a flexible temperature sensor. Background Art

[0002] The core of a temperature sensor is the temperature-sensitive layer, and the properties of the sensitive layer determine the sensitivity and stability of the sensor. Usually, the resistance property of the temperature-sensing layer is affected by strain, resulting in false signals or signal offsets, which directly affect the accuracy and reliability of the temperature sensor.

[0003] In view of this, a simple and effective method is needed to improve the mechanical anti-interference ability of the temperature-sensitive material, reduce the signal offset and false signals caused by strain, and thus improve the accuracy of temperature detection. The island-bridge structure is a common fine structure that can effectively avoid the influence of strain on temperature response. However, usually, the spatial resolution of screen printing is several hundred micrometers, making it difficult to fabricate a precise island-bridge structure. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for manufacturing a flexible temperature sensor. The solution of the present invention can solve the problems existing in the above prior art.

[0005] Technical solution of the present invention:

[0006] According to the first aspect, a method for manufacturing a flexible temperature sensor is provided, including the following steps:

[0007] Using a lithography process to prepare a required temperature sensor pattern on a photoresist as a mask for manufacturing a flexible temperature sensor, and the edge of the mask forming the required pattern shape is an inverted trapezoid structure;

[0008] After stripping the mask, transfer and fix it on the lower surface of the etched electrode pattern screen;

[0009] Using screen printing to prepare a carbon electrode on a flexible substrate;

[0010] Fabricate a temperature-sensitive material and a screen with a temperature-sensitive layer pattern;

[0011] Using laminated screen printing to prepare a temperature-sensitive layer made of a temperature-sensitive material on a flexible substrate, thereby obtaining a complete temperature sensor.

[0012] Further, the photoresist is a photosensitive PI photoresist.

[0013] Further, the transfer method uses a liquid-phase assisted transfer technique.

[0014] Further, the thickness of the mask is greater than 50 micrometers.

[0015] Further, the method for obtaining the temperature-sensitive material is as follows:

[0016] Add 30 mg of carbon nanotubes and 0.5 mL of sodium polystyrene sulfonate to 10 mL of deionized water, and ultrasonically mix until uniform without obvious precipitate;

[0017] Mix the above mixed solution with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), where the weight ratio of poly(3,4-ethylenedioxythiophene) to poly(styrenesulfonic acid) is 1.3%, and mix evenly at a ratio of 1:2 to 1:7.

[0018] Further, the method for manufacturing a flexible temperature sensor further includes drying the carbon electrode and curing the temperature-sensitive layer.

[0019] According to a second aspect, there is provided a flexible temperature sensor, which is manufactured by the method described in the present invention.

[0020] Advantages of the present invention compared with the prior art:

[0021] (1) The present invention uses a mask with an inverted trapezoidal structure to promote ink separation, thereby improving the accuracy of the island-bridge structure, reducing the piezoresistive response of the temperature sensor, and thus improving the measurement accuracy of the temperature sensor;

[0022] (2) The temperature-sensitive material obtained by mixing carbon nanotubes, sodium polystyrene sulfonate and poly(3,4-ethylenedioxythiophene) in proportion in the present invention can greatly enhance the anti-strain interference ability of the temperature sensor and improve the stability and accuracy of temperature sensing. Description of the Drawings

[0023] The accompanying drawings included are used to provide a further understanding of the embodiments of the present invention, which form a part of the specification, are used to illustrate the embodiments of the present invention, and are used to explain the principles of the present invention together with the written description. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0024] Figure 1 Shows a schematic diagram of the steps of a method for manufacturing a flexible temperature sensor according to an embodiment of the present invention;

[0025] Figure 2 Shows a schematic diagram of the inner edge structure of the mask according to an embodiment of the present invention;

[0026] Figure 3 Shows a schematic diagram of the structure of the temperature sensor according to an embodiment of the present invention;

[0027] Figure 4 Shows a schematic diagram of the performance test results of a temperature sensor provided according to an embodiment of the present invention;

[0028] Figure 5 Shows a schematic diagram of the repeated bending stability performance test results of a temperature sensor provided according to an embodiment of the present invention.

[0029] The above-mentioned drawings include the following reference numerals:

[0030] 1. Screen printing stencil; 2. Mask; 3. Trapezoidal structure; 4. Carbon electrode; 5. Temperature-sensitive layer. Detailed implementation manners

[0031] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] It should be noted that the terms used herein are only for describing the specific implementation manners and are not intended to limit the exemplary implementation manners according to the present application. As used herein, unless otherwise clearly specified in the context, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprise" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] Unless otherwise specifically stated, the relative arrangements of the components and steps, numerical expressions and values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for the convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed herein, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0034] Such as Figure 1As shown, according to an embodiment of the first aspect of the present invention, a method for manufacturing a flexible temperature sensor is provided, including the following steps:

[0035] Using a lithography process to prepare a required temperature sensor pattern on a photoresist as a mask for manufacturing the flexible temperature sensor, the edge of the mask forming the required pattern shape is an inverted trapezoidal structure, as Figure 2 shown;

[0036] After stripping the mask, transfer and fix it to the lower surface of the etched electrode pattern screen;

[0037] Using screen printing to prepare a carbon electrode on a flexible substrate;

[0038] Fabricate a temperature-sensitive material and a screen with a temperature-sensitive layer pattern engraved;

[0039] Using laminated screen printing to prepare a temperature-sensitive layer made of a temperature-sensitive material on a flexible substrate, thereby obtaining a complete temperature sensor.

[0040] Through the above method, the mask uses the inverted trapezoidal structure to promote ink separation, thereby improving the accuracy of the island-bridge structure, reducing the piezoresistive response of the temperature sensor, and thus improving the measurement accuracy of the temperature sensor.

[0041] Further, in one embodiment, the photoresist is a photosensitive PI photoresist. In other embodiments, other types of photoresists can be selected, which will not be elaborated here one by one.

[0042] Further, in one embodiment, the transfer method uses a liquid-phase assisted transfer technique. In other embodiments, other types of transfer techniques can be selected, which will not be elaborated here one by one.

[0043] Further, in one embodiment, the mask thickness is greater than 50 microns. With this setting, it is beneficial to the separation of the ink.

[0044] Further, in one embodiment, the method for obtaining the temperature-sensitive material is:

[0045] Add 30 mg of carbon nanotubes and 0.5 mL of sodium polystyrene sulfonate to 10 mL of deionized water and ultrasonically mix until uniform without obvious precipitates;

[0046] Mix the above mixed solution with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT:PSS, 1.3 wt%) in a ratio of 1:2 to 1:7 and mix evenly.

[0047] The temperature-sensitive material obtained through this composite material and ratio can greatly enhance the anti-strain interference ability of the temperature sensor and improve the stability and accuracy of temperature sensing.

[0048] Further, in one embodiment, a method for manufacturing a flexible temperature sensor further includes drying the carbon electrode and curing the temperature-sensitive layer. In a specific embodiment, drying is performed at 120 °C for 1 hour to completely dry the carbon electrode;

[0049] According to an embodiment of the second aspect, a flexible temperature sensor is provided, which is manufactured by using the method described in the present invention, as Figure 2 , 3 shown.

[0050] For a further understanding of a method for manufacturing a flexible temperature sensor provided by the present invention, the following detailed description will be given in conjunction with specific examples and drawings.

[0051] A method for manufacturing a flexible temperature sensor includes the following steps:

[0052] 1. Mask preparation: In this project, a photosensitive PI photoresist is used to prepare the required pattern through a lithography process. The mask is peeled off using a liquid-phase assisted transfer technique.

[0053] 2. Stacked mask preparation: The mask is transferred and fixed to the lower surface of a screen printing with a specific pattern using a liquid-phase assisted transfer technique. The screen printing serves as a support, controls the ink volume, and prepares large patterns. The PI mask uses an inverted trapezoidal structure to promote ink separation and prepare fine part patterns.

[0054] 3. Preparation of carbon electrode: The carbon electrode is prepared using screen printing. A screen printing stencil is designed and prepared, and a highly conductive carbon ink is used as the electrode material. The carbon electrode is printed on the PI flexible substrate, and after printing, it is dried at 120 °C for 1 hour to ensure complete drying of the electrode.

[0055] 4. Preparation of temperature-sensitive material: First, 30 mg of carbon nanotubes (CNT) and 0.5 mL of sodium polystyrene sulfonate (PSS) are added to 10 mL of deionized water and ultrasonically mixed until uniform and without obvious precipitates. The above mixed solution is mixed uniformly with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT:PSS, 1.3 wt%) in a ratio of 1:7

[0056] 5. Device preparation: Stacked screen printing is used to print a precise island-bridge structure as a mask. Then, it is cured at 70 °C to obtain a temperature sensor.

[0057] The temperature sensor manufactured through the above steps is subjected to performance testing, as Figure 4 and Figure 5 shown, achieving temperature detection in the range of 0-200 °C, with a detection limit of approximately 0.02 °C, and the signal hardly changes during repeated bending strain.

[0058] In summary, the manufacturing method of a flexible temperature sensor and the flexible temperature sensor provided by the present invention have at least the following advantages compared with the prior art:

[0059] (1) The present invention uses a mask with an inverted trapezoidal structure to promote ink separation, thereby improving the accuracy of the island-bridge structure, reducing the piezoresistive response of the temperature sensor, and thus improving the measurement accuracy of the temperature sensor;

[0060] (2) The present invention uses a temperature-sensitive material obtained by mixing carbon nanotubes, sodium polystyrene sulfonate, and poly(3,4-ethylenedioxythiophene) in proportion, which can greatly enhance the anti-strain interference ability of the temperature sensor and improve the stability and accuracy of temperature sensing.

[0061] For ease of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" etc. can be used here to describe the spatial positional relationship of a device or feature shown in the figure with other devices or features. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is inverted, a device described as "above other devices or structures" or "over other devices or structures" will then be positioned "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations for the spatial relative descriptions used here will be made accordingly.

[0062] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of differentiating the corresponding components. Without additional statements, the above terms have no special meanings, and thus cannot be construed as limiting the protection scope of the present invention.

[0063] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A manufacturing method of a flexible temperature sensor, characterized in that, it includes the following steps: Using photolithography to prepare the required temperature sensor pattern on the photoresist as a mask for manufacturing the flexible temperature sensor, and the edge of the mask forming the required pattern shape is an inverted trapezoid structure; After stripping the mask, transfer and fix it on the lower surface of the engraved electrode pattern screen; Use screen printing to prepare carbon electrodes on the flexible substrate; Fabricate the temperature-sensitive material and the screen with the temperature-sensitive layer pattern engraved; Use laminated screen printing to prepare a temperature-sensitive layer made of the temperature-sensitive material on the flexible substrate, thereby obtaining a complete temperature sensor.

2. The manufacturing method of a flexible temperature sensor according to claim 1, characterized in that, the photoresist is a photosensitive PI photoresist.

3. The manufacturing method of a flexible temperature sensor according to claim 2, characterized in that, the transfer method adopts a liquid-phase assisted transfer technology.

4. The manufacturing method of a flexible temperature sensor according to claim 3, characterized in that, the thickness of the mask is greater than 50 microns.

5. The manufacturing method of a flexible temperature sensor according to claim 4, characterized in that, the method for obtaining the temperature-sensitive material is: Add 30 mg of carbon nanotubes and 0.5 mL of sodium polystyrene sulfonate to 10 mL of deionized water and ultrasonically mix until uniform without obvious precipitate; Mix the above mixed solution with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), wherein the weight ratio of poly(3,4-ethylenedioxythiophene) to poly(styrenesulfonic acid) is 1.3%, and mix evenly at a ratio of 1:2 to 1:

7.

6. The manufacturing method of a flexible temperature sensor according to claim 5, characterized in that, it also includes drying of the carbon electrodes and curing of the temperature-sensitive layer.

7. A flexible temperature sensor, characterized in that, the flexible temperature sensor is obtained by using the manufacturing method of the flexible temperature sensor according to any one of claims 1-6.

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