CN113311031A - Double-sided capacitive humidity sensor and preparation method thereof - Google Patents
Double-sided capacitive humidity sensor and preparation method thereof Download PDFInfo
- Publication number
- CN113311031A CN113311031A CN202110743766.9A CN202110743766A CN113311031A CN 113311031 A CN113311031 A CN 113311031A CN 202110743766 A CN202110743766 A CN 202110743766A CN 113311031 A CN113311031 A CN 113311031A
- Authority
- CN
- China
- Prior art keywords
- layer
- electrode layer
- double
- electrode
- humidity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/22—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance
- G01N27/223—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance for determining moisture content, e.g. humidity
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/22—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance
- G01N27/226—Construction of measuring vessels; Electrodes therefor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/22—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance
- G01N27/228—Circuits therefor
Abstract
The invention relates to a double-sided capacitive humidity sensor and a preparation method thereof, belonging to the technical field of sensors. The double-sided capacitance type humidity sensor comprises a substrate, a first electrode layer, a first humidity sensing layer, a second electrode layer and a second humidity sensing layer; the first electrode layer and the second electrode layer are respectively connected with two sides of the substrate, the first humidity sensing layer covers the first electrode layer, and the second humidity sensing layer covers the second electrode layer. The invention also provides a preparation method of the double-sided capacitive humidity sensor. This two-sided electric capacity type humidity transducer can two-sided humidity detection, can be more comprehensive carry out humidity to the environment that awaits measuring and detect, improves and feels wet efficiency.
Description
Technical Field
The invention belongs to the technical field of sensors, and particularly relates to a double-sided capacitive humidity sensor and a preparation method thereof.
Background
Atmospheric humidity measurement is an important requirement in most areas of meteorological activity, such as weather analysis and forecasting, agriculture, aviation service, and environmental research, to name a few specific applications. Currently, humidity measurement is usually performed by placing the humidity sensor in a bare environment, in direct contact with the air. At present, a common macromolecule capacitance type humidity sensor is formed by preparing a metal electrode and a humidity sensitive material on the upper surface of a substrate as a humidity sensitive medium layer.
However, when the macromolecule capacitance type humidity sensor is applied to components, the environment humidity to be measured can only be changed by sensing the environment humidity from the upper surface of the chip, and the space is limited, so that the humidity measurement error exists, and the problem of low humidity sensing efficiency exists.
Disclosure of Invention
The invention provides a double-sided capacitance type humidity sensor and a preparation method thereof, which can be used for double-sided humidity detection, can be used for more comprehensively detecting the humidity of an environment to be detected and improving the humidity sensing efficiency.
In order to solve the above technical problems, the present invention provides a double-sided capacitive humidity sensor.
The technical scheme for solving the technical problems is as follows: a double-sided capacitive humidity sensor comprises a substrate, a first electrode layer, a first humidity sensing layer, a second electrode layer and a second humidity sensing layer;
the first electrode layer and the second electrode layer are respectively connected with two sides of the substrate, the first humidity sensing layer covers the first electrode layer, and the second humidity sensing layer covers the second electrode layer.
The double-sided capacitive humidity sensor has the beneficial effects that: (1) the double-sided capacitive humidity sensor can detect air humidity change on double sides, has high humidity sensitivity and wide detection space range, and can be connected with two or more double-sided capacitive humidity sensors in series on the same substrate, so that the series connection or the parallel connection of the multiple double-sided capacitive humidity sensors can be realized;
(2) the double-sided capacitance type humidity sensor can achieve a wider capacitance value adjusting range under the condition that the area of a chip is unchanged, and is suitable for various application environments.
On the basis of the technical scheme, the invention can be further improved as follows.
Further, a third electrode layer covers the first humidity sensing layer.
The beneficial effect of adopting the further scheme is that: the double-sided capacitive humidity sensor with different structures can be selected for combined design according to the capacitance value requirement, so that the humidity-sensitive capacitance value can be greatly improved, the design requirements of different capacitance values can be met, and the application is flexible.
Further, a fourth electrode layer covers the second humidity sensing layer.
The beneficial effect of adopting the further scheme is that: the double-sided capacitive humidity sensor with different structures can be selected for combined design according to the capacitance value requirement, so that the humidity-sensitive capacitance value can be greatly improved, the design requirements of different capacitance values can be met, and the application is flexible.
Further, the first electrode layer and the second electrode layer are interdigital electrode layers, double electrode layers or single electrode layers.
The beneficial effect of adopting the further scheme is that: the double-sided capacitive humidity sensor with different structures can be selected for combined design according to the capacitance value requirement, so that the humidity-sensitive capacitance value can be greatly improved, the design requirements of different capacitance values can be met, and the application is flexible.
Further, the third electrode layer and the fourth electrode layer are single electrode layers.
The beneficial effect of adopting the further scheme is that: the series-parallel connection is facilitated.
Further, the substrate is ceramic, glass or silicon wafer.
The beneficial effect of adopting the further scheme is that: the double-sided capacitance type humidity sensor is beneficial to processing.
Secondly, the present invention provides a method for manufacturing a double-sided capacitive humidity sensor to solve the above technical problems.
The technical scheme for solving the technical problems is as follows: a preparation method of the double-sided capacitance type humidity sensor comprises the following steps:
s1, taking a substrate, photoetching one surface of the substrate, cleaning, uniformly coating photoresist, prebaking, exposing and developing to obtain a photoresist pattern;
s2, depositing an electrode metal film on one surface of the substrate, soaking the electrode metal film in stripping liquid, and stripping off metal outside the photoresist pattern to obtain a first electrode layer;
s3, coating a polyamic acid solution on the first electrode layer in the step S2, and pre-curing to obtain a cured layer;
s4, photoetching the solidified layer obtained in the step S3, directly and uniformly coating photoresist on the solidified layer, prebaking, exposing and developing to obtain a solidified layer pattern, carrying out wet etching, and carrying out imidization to obtain a first humidity-sensitive layer;
s5, repeating the steps S1-S4 on the other side of the substrate to obtain the double-sided capacitance type humidity sensor.
The preparation method of the invention has the beneficial effects that: (1) the preparation method can be used for conveniently preparing the double-sided capacitive humidity sensor, and is very simple to operate;
the double-sided capacitive humidity sensor prepared by the preparation method can detect air humidity change on double sides, has high humidity sensitivity and wide detection space range, and can be connected with two or more double-sided capacitive humidity sensors in series on the same substrate, so that the series connection or the parallel connection of the multiple double-sided capacitive humidity sensors can be realized.
On the basis of the technical scheme, the invention can be further improved as follows.
Further, the method also comprises the following steps:
s6, depositing an electrode metal film on the first humidity-sensing layer obtained in the step S4, photoetching, uniformly coating photoresist, prebaking, exposing and developing to obtain an electrode metal film pattern;
and S7, carrying out wet etching on the electrode metal film pattern obtained in the step S6 to obtain a third electrode layer.
The beneficial effect of adopting the further scheme is that: the double-sided capacitive humidity sensors with different structures can be selected for combined design according to the capacitance value requirements, and the corresponding double-sided capacitive humidity sensors are prepared.
Further, in step S1 and step S4, the temperature of the pre-baking is 80-110 ℃, the time of the exposure is 5-8S, and the time of the development is 6-15S.
The beneficial effect of adopting the further scheme is that: the photoetching operation is facilitated.
Further, in step S3, the temperature of the pre-curing is 70-120 ℃, and the time is 20-50 min; in step S4, the imidization is performed by taking a gradient of 20-40 ℃ from 100 ℃ and keeping the temperature for 3-5h, wherein each gradient is separated by 20-40min, and the temperature is increased to 300 ℃.
The beneficial effect of adopting the further scheme is that: is favorable for imidizing the polyamide acid solution into a film with humidity sensing performance.
Drawings
Fig. 1 is a schematic structural view of a double-sided capacitance type humidity sensor according to embodiment 1 of the present invention;
FIG. 2 is a schematic structural view of a double-sided capacitive humidity sensor according to embodiments 2 to 3 of the present invention;
FIG. 3 is a schematic structural view of a double-sided capacitive humidity sensor according to embodiments 4 to 5 of the present invention;
fig. 4 is a schematic perspective view of a double-sided capacitive humidity sensor according to embodiments 4 to 5 of the present invention.
In the drawings, the components represented by the respective reference numerals are listed below:
1. the substrate comprises a substrate body, 2, a first electrode layer, 3, a first humidity sensing layer, 4, a second electrode layer, 5, a third electrode layer, 6, a second humidity sensing layer, 7 and a fourth electrode layer.
Detailed Description
The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.
Example 1
As shown in fig. 1, the present embodiment provides a double-sided capacitance type humidity sensor including a substrate 1, a first electrode layer 2, a first humidity-sensing layer 3, a second electrode layer 4, and a second humidity-sensing layer 6.
The first electrode layer 2 and the second electrode layer 4 are respectively connected with two sides of the substrate 1 and are attached to two sides of the substrate 1, the first humidity sensing layer 3 covers the first electrode layer 2, and the second humidity sensing layer 6 covers the second electrode layer 4.
Wherein the first electrode layer 2 and the second electrode layer 4 are interdigital electrode layers. The areas of the first electrode layer 2 and the second electrode layer 4 and the areas of the first humidity sensing layer 3 and the second humidity sensing layer 6 can be the same or different, and the electrode can be designed according to actual conditions. Therefore, the double-sided capacitive humidity sensor is a double-sided interdigital capacitive humidity sensor.
Wherein the substrate 1 is glass. The first electrode layer 2 and the second electrode layer 4 are made of TiW/Au, but it is also possible to use a metal material with good conductivity and semiconductor processability, such as Cu, Pt, Cr, Ni, NiCr, AlCu, etc.
The embodiment also provides a preparation method of the double-sided capacitive humidity sensor, which comprises the following steps:
s1, taking the glass substrate 1, cleaning, photoetching one surface of the substrate 1, cleaning, uniformly coating photoresist, prebaking at 90 ℃, exposing for 6S, and developing for 8S to obtain a photoresist pattern. The photoresist is a positive photoresist or a negative photoresist, which is an existing material.
S2, putting the substrate 1 in a vacuum environment, pre-sputtering one surface of the substrate 1 for 15S, then sputtering a TiW layer for 40S, keeping the vacuum environment, finally sputtering an Au metal layer for 80S, completing magnetron sputtering, depositing to form an electrode metal film, soaking in stripping liquid for 30min, and stripping off the metal outside the photoresist pattern to obtain the first electrode layer 2. Wherein the stripping solution is a conventional material. The deposition of the electrode metal film can also be prepared by thermal evaporation and electron beam evaporation.
S3, the first electrode layer 2 of step S2 is coated with a polyamic acid solution and precured at 90 ℃ for 40min to obtain a cured layer.
The polyamic acid solution is prepared by taking diamine and dianhydride as raw materials, adding DMAc solvent, and stirring and reacting at low temperature to obtain the polyamic acid solution. Polyamic acid solutions are known in the art.
S4, photoetching the solidified layer obtained in the step S3, directly and uniformly coating photoresist on the solidified layer, baking at 100 ℃, exposing for 6S, developing for 12S to obtain a solidified layer pattern, coating a developing solution, carrying out wet etching, raising the temperature to 300 ℃ from 100 ℃ at 25 ℃ as a gradient with each gradient interval of 35min, and then keeping for 5h for imidization to obtain the first humidity sensing layer 3. The photoresist is a positive photoresist or a negative photoresist, which is an existing material.
S5, repeating the steps S1-S4 on the other side of the substrate 1 to obtain the second electrode layer 4 and the second humidity sensing layer 6, and thus obtaining the double-sided capacitance type humidity sensor.
Example 2
As shown in fig. 2, the present embodiment provides a double-sided capacitance type humidity sensor including a substrate 1, a first electrode layer 2, a first humidity-sensing layer 3, a second electrode layer 4, a second humidity-sensing layer 6, and a third electrode layer 5.
The first electrode layer 2 and the second electrode layer 4 are respectively connected with two sides of the substrate 1 and are attached to two sides of the substrate 1, the first humidity sensing layer 3 covers the first electrode layer 2, and the second humidity sensing layer 6 covers the second electrode layer 4. The third electrode layer 5 covers the first humidity sensing layer 3.
Wherein the first electrode layer 2 and the second electrode layer 4 are double electrode layers. The areas of the first electrode layer 2 and the second electrode layer 4 and the areas of the first humidity sensing layer 3 and the second humidity sensing layer 6 can be the same or different, and the electrode can be designed according to actual conditions. The third electrode layer 5 is a single electrode layer. Thus, the double-sided capacitive humidity sensor is a double-sided hybrid capacitive humidity sensor.
Wherein the substrate 1 is glass. The first electrode layer 2 and the second electrode layer 4 are made of Ti/Al, but a metal material with good conductivity and capable of being processed by a semiconductor, such as Cu, Pt, Cr, Ni, NiCr, AlCu, etc., may be used.
The embodiment also provides a preparation method of the double-sided capacitive humidity sensor, which comprises the following steps:
s1, taking the glass substrate 1, cleaning, photoetching one surface of the substrate 1, cleaning, uniformly coating photoresist, prebaking at 110 ℃, exposing for 8S, and developing for 15S to obtain a photoresist pattern. The photoresist is a positive photoresist or a negative photoresist, which is an existing material.
S2, putting the substrate 1 in a vacuum environment, pre-sputtering one surface of the substrate 1 for 50S, then sputtering a TiW layer for 80S, keeping the vacuum environment, finally sputtering an Al metal layer for 150S, completing magnetron sputtering, depositing to form an electrode metal film, soaking in stripping liquid for 25min, and stripping off the metal outside the photoresist pattern to obtain the first electrode layer 2. Wherein the stripping solution is a conventional material. The deposition of the electrode metal film can also be prepared by thermal evaporation and electron beam evaporation.
S3, the first electrode layer 2 of step S2 is coated with a polyamic acid solution and precured at 120 ℃ for 20min to obtain a cured layer.
The polyamic acid solution is prepared by taking diamine and dianhydride as raw materials, adding DMAc solvent, and stirring and reacting at low temperature to obtain the polyamic acid solution. Polyamic acid solutions are known in the art.
S4, photoetching the solidified layer obtained in the step S3, directly and uniformly coating photoresist on the solidified layer, prebaking at 110 ℃, exposing for 5S, developing for 6S to obtain a solidified layer pattern, coating a developing solution, carrying out wet etching, raising the temperature to 300 ℃ from 100 ℃ at 20 ℃ as a gradient with each gradient interval being 20min, and then keeping for 3h for imidization to obtain the first humidity-sensing layer 3. The photoresist is a positive photoresist or a negative photoresist, which is an existing material.
S5, repeating the steps S1-S4 on the other side of the substrate 1 to obtain the second electrode layer 4 and the second humidity sensing layer 6.
And S6, in a vacuum environment, pre-sputtering the first humidity sensing layer 3 obtained in the step S4 for 50S, then sputtering a TiW layer for 100S, keeping the vacuum environment, finally sputtering an Al metal layer for 200S, completing magnetron sputtering, depositing to form an electrode metal film, photoetching, uniformly coating photoresist, baking at 110 ℃, exposing for 8S, and developing for 15S to obtain an electrode metal film pattern. The deposition of the electrode metal film can also be prepared by thermal evaporation.
And S7, placing the electrode metal film pattern obtained in the step S6 in an Al corrosive liquid, soaking for 20min, and obtaining a third electrode layer 5 by using metal Al outside the electrode metal film pattern area, namely obtaining the double-sided capacitive humidity sensor.
Example 3
As shown in fig. 2, the present embodiment provides a double-sided capacitance type humidity sensor including a substrate 1, a first electrode layer 2, a first humidity-sensing layer 3, a second electrode layer 4, a second humidity-sensing layer 6, and a third electrode layer 5.
The first electrode layer 2 and the second electrode layer 4 are respectively connected with two sides of the substrate 1, the first humidity sensing layer 3 is covered on the first electrode layer 2, and the second humidity sensing layer 6 is covered on the second electrode layer 4. The third electrode layer 5 covers the first humidity sensing layer 3.
The first electrode layer 2 is a double-electrode layer, and the second electrode layer 4 is an interdigital electrode layer. The areas of the first electrode layer 2 and the second electrode layer 4 and the areas of the first humidity sensing layer 3 and the second humidity sensing layer 6 can be the same or different, and the electrode can be designed according to actual conditions. The third electrode layer 5 is a single electrode layer. Thus, the double-sided capacitive humidity sensor is a double-sided hybrid capacitive humidity sensor.
Wherein the substrate 1 is ceramic. The first electrode layer 2 and the second electrode layer 4 are made of Ti/Al, but a metal material with good conductivity and capable of being processed by a semiconductor, such as Cu, Pt, Cr, Ni, NiCr, AlCu, etc., may be used.
The embodiment also provides a preparation method of the double-sided capacitive humidity sensor, which comprises the following steps:
s1, taking the ceramic substrate 1, cleaning, photoetching one surface of the substrate 1, cleaning, uniformly coating photoresist, prebaking at 95 ℃, exposing for 7S, and developing for 8S to obtain a photoresist pattern. The photoresist is a positive photoresist or a negative photoresist, which is an existing material.
S2, putting the substrate 1 in a vacuum environment, firstly performing Ti metal layer evaporation plating of 10nm on one surface of the substrate 1, keeping the vacuum atmosphere, sputtering Al metal layer of 0.1um, completing electron beam evaporation plating, depositing to form an electrode metal film, then soaking in stripping liquid for 25min, stripping off metal outside the photoresist pattern, and obtaining the first electrode layer 2. Wherein the stripping solution is a conventional material. The deposition of the electrode metal film can also be prepared by thermal evaporation.
S3, the first electrode layer 2 of step S2 is coated with a polyamic acid solution and precured at 110 ℃ for 25min to obtain a cured layer.
The polyamic acid solution is prepared by taking diamine and dianhydride as raw materials, adding DMAc solvent, and stirring and reacting at low temperature to obtain the polyamic acid solution. Polyamic acid solutions are known in the art.
S4, photoetching the solidified layer obtained in the step S3, directly and uniformly coating photoresist on the solidified layer, baking at 110 ℃, exposing for 6S, developing for 10S to obtain a solidified layer pattern, coating a developing solution, carrying out wet etching, raising the temperature to 300 ℃ from 100 ℃ at 40 ℃ as a gradient with each gradient interval of 40min, and then keeping for 4h for imidization to obtain the first humidity sensing layer 3. The photoresist is a positive photoresist or a negative photoresist, which is an existing material.
S5, repeating the steps S1-S4 on the other side of the substrate 1 to obtain the second electrode layer 4 and the second humidity sensing layer 6.
S6, in a vacuum environment, performing Ti metal layer evaporation plating of 8nm on the first humidity sensing layer 3 obtained in the step S4, keeping a vacuum atmosphere, sputtering an Al metal layer of 0.2um, completing electron beam evaporation plating, depositing to form an electrode metal film, photoetching, uniformly coating photoresist, prebaking at 110 ℃, exposing for 8S, and developing for 14S to obtain an electrode metal film pattern. The deposition of the electrode metal film can also be prepared by thermal evaporation.
And S7, placing the electrode metal film pattern obtained in the step S6 in an Al corrosive liquid, soaking for 15min, and obtaining a third electrode layer 5 by using metal Al outside the electrode metal film pattern area, namely obtaining the double-sided capacitive humidity sensor.
Example 4
As shown in fig. 3 and 4, the present embodiment provides a double-sided capacitance type humidity sensor including a substrate 1, a first electrode layer 2, a first humidity sensing layer 3, a second electrode layer 4, a second humidity sensing layer 6, a third electrode layer 5, and a fourth electrode layer 7.
The first electrode layer 2 and the second electrode layer 4 are respectively connected with two sides of the substrate 1, the first humidity sensing layer 3 is covered on the first electrode layer 2, and the second humidity sensing layer 6 is covered on the second electrode layer 4. The third electrode layer 5 overlies the first moisture-sensing layer 3 and the fourth electrode layer 7 overlies the second moisture-sensing layer 6.
Wherein the first electrode layer 2 and the second electrode layer 4 are double electrode layers. The areas of the first electrode layer 2 and the second electrode layer 4 and the areas of the first humidity sensing layer 3 and the second humidity sensing layer 6 can be the same or different, and the electrode can be designed according to actual conditions. The third electrode layer 5 and the fourth electrode layer 7 are single electrode layers. Thus, the double-sided capacitive humidity sensor is a double-sided sandwich type capacitive humidity sensor.
Wherein the substrate 1 is ceramic. The first electrode layer 2 and the second electrode layer 4 are made of Ti/Al, but a metal material with good conductivity and capable of being processed by a semiconductor, such as Cu, Pt, Cr, Ni, NiCr, AlCu, etc., may be used.
The embodiment also provides a preparation method of the double-sided capacitive humidity sensor, which comprises the following steps:
s1, cleaning the ceramic substrate 1, photoetching one surface of the substrate 1, cleaning, uniformly coating photoresist, prebaking at 90 ℃, exposing for 6S, and developing for 11S to obtain a photoresist pattern. The photoresist is a positive photoresist or a negative photoresist, which is an existing material.
S2, putting the substrate 1 in a vacuum environment, firstly performing 6nm Ti metal layer evaporation on one surface of the substrate 1, keeping the vacuum environment, sputtering 0.2um Al metal layer, completing electron beam evaporation, depositing to form an electrode metal film, then soaking in stripping liquid for 50S, stripping off the metal outside the photoresist pattern, and obtaining the first electrode layer 2. Wherein the stripping solution is a conventional material. The deposition of the electrode metal film can also be prepared by thermal evaporation.
S3, the first electrode layer 2 of step S2 is coated with a polyamic acid solution and precured at 70 ℃ for 50min to obtain a cured layer.
The polyamic acid solution is prepared by taking diamine and dianhydride as raw materials, adding DMAc solvent, and stirring and reacting at low temperature to obtain the polyamic acid solution. Polyamic acid solutions are known in the art.
S4, photoetching the solidified layer obtained in the step S3, directly and uniformly coating photoresist on the solidified layer, prebaking at 110 ℃, exposing for 8S, developing for 9S to obtain a solidified layer pattern, coating a developing solution, carrying out wet etching, raising the temperature to 300 ℃ from 100 ℃ at 30 ℃ as a gradient with each gradient interval of 30min, and then keeping for 3h for imidization to obtain the first humidity-sensing layer 3. The photoresist is a positive photoresist or a negative photoresist, which is an existing material.
S5, repeating the steps S1-S4 on the other side of the substrate 1 to obtain the second electrode layer 4 and the second humidity sensing layer 6.
S6, in a vacuum environment, performing evaporation plating on a Ti metal layer of 13nm on the first humidity sensing layer 3 obtained in the step S4, keeping a vacuum atmosphere, sputtering an Al metal layer of 0.1um, completing electron beam evaporation plating, depositing to form an electrode metal film, photoetching, uniformly coating photoresist, prebaking at 95 ℃, exposing for 6S, and developing for 13S to obtain an electrode metal film pattern. The deposition of the electrode metal film can also be prepared by thermal evaporation and electron beam evaporation.
And S7, placing the electrode metal film pattern obtained in the step S6 in an Al corrosive liquid, and soaking for 10min to obtain metal Al outside the electrode metal film pattern area, namely the third electrode layer 5.
S8, repeating the operations of steps S6 and S7 on the second humidity sensing layer 6 to obtain the fourth electrode layer 7, i.e., the double-sided capacitive humidity sensor.
Example 5
As shown in fig. 3 and 4, the present embodiment provides a double-sided capacitance type humidity sensor including a substrate 1, a first electrode layer 2, a first humidity sensing layer 3, a second electrode layer 4, a second humidity sensing layer 6, a third electrode layer 5, and a fourth electrode layer 7.
The first electrode layer 2 and the second electrode layer 4 are respectively connected with two sides of the substrate 1, the first humidity sensing layer 3 is covered on the first electrode layer 2, and the second humidity sensing layer 6 is covered on the second electrode layer 4. The third electrode layer 5 overlies the first moisture-sensing layer 3 and the fourth electrode layer 7 overlies the second moisture-sensing layer 6.
Wherein the first electrode layer 2 and the second electrode layer 4 are single electrode layers. The areas of the first electrode layer 2 and the second electrode layer 4 and the areas of the first humidity sensing layer 3 and the second humidity sensing layer 6 can be the same or different, and the electrode can be designed according to actual conditions. The third electrode layer 5 and the fourth electrode layer 7 are single electrode layers. Thus, the double-sided capacitive humidity sensor is a double-sided single-electrode capacitive humidity sensor.
Wherein the substrate 1 is ceramic. The first electrode layer 2 and the second electrode layer 4 are made of Ti/Al, but a metal material with good conductivity and capable of being processed by a semiconductor, such as Cu, Pt, Cr, Ni, NiCr, AlCu, etc., may be used.
The embodiment also provides a preparation method of the double-sided capacitive humidity sensor, which comprises the following steps:
s1, taking the ceramic substrate 1, cleaning, photoetching one surface of the substrate 1, cleaning, uniformly coating photoresist, prebaking at 110 ℃, exposing for 5S, and developing for 6S to obtain a photoresist pattern. The photoresist is a positive photoresist or a negative photoresist, which is an existing material.
S2, putting the substrate 1 in a vacuum environment, pre-sputtering one surface of the substrate 1 for 20S, then sputtering a TiW layer for 60S, keeping the vacuum environment, finally sputtering an Al metal layer for 140S, completing magnetron sputtering, depositing to form an electrode metal film, soaking the electrode metal film in stripping liquid for 50S, and stripping off the metal outside the photoresist pattern to obtain the first electrode layer 2. Wherein the stripping solution is a conventional material. The deposition of the electrode metal film can also be prepared by thermal evaporation.
S3, the first electrode layer 2 of step S2 is coated with a polyamic acid solution and precured at 80 ℃ for 25min to obtain a cured layer.
The polyamic acid solution is prepared by taking diamine and dianhydride as raw materials, adding DMAc solvent, and stirring and reacting at low temperature to obtain the polyamic acid solution. Polyamic acid solutions are known in the art.
S4, photoetching the solidified layer obtained in the step S3, directly and uniformly coating photoresist on the solidified layer, baking at 110 ℃, exposing for 5S, developing for 15S to obtain a solidified layer pattern, coating a developing solution, carrying out wet etching, raising the temperature to 300 ℃ from 100 ℃ at 40 ℃ as a gradient with each gradient interval of 40min, and then keeping for 5h for imidization to obtain the first humidity sensing layer 3. The photoresist is a positive photoresist or a negative photoresist, which is an existing material.
S5, repeating the steps S1-S4 on the other side of the substrate 1 to obtain the second electrode layer 4 and the second humidity sensing layer 6.
And S6, in a vacuum environment, pre-sputtering the first humidity sensing layer 3 obtained in the step S4 for 40S, then sputtering a TiW layer for 80S, keeping the vacuum environment, finally sputtering an Al metal layer for 160S, completing magnetron sputtering, depositing to form an electrode metal film, photoetching, uniformly coating photoresist, baking at 110 ℃, exposing for 6S, and developing for 12S to obtain an electrode metal film pattern. The deposition of the electrode metal film can also be prepared by thermal evaporation.
And S7, placing the electrode metal film pattern obtained in the step S6 in an Al corrosive liquid, soaking for 20S, and obtaining the third electrode layer 5 by using metal Al outside the electrode metal film pattern area.
S8, repeating the operations of steps S6 and S7 on the second humidity sensing layer 6 to obtain the fourth electrode layer 7, i.e., the double-sided capacitive humidity sensor.
This two-sided electric capacity type humidity transducer when using, multiple assembly methods such as accessible external lead, welding leg or flip-chip bonding are assembled with test circuit, establish ties or parallelly connected together with two sides of two-sided electric capacity type humidity transducer, can enough increase the space ability of sensing of wetting sensitive electric capacity, also make appearance value greatly increased to improve the sensitivity of sensing wet, reduce the requirement to the test circuit precision. And the adjustment design of the capacity value can be carried out according to different use requirements, so that the application is more flexible. In addition, the double-sided capacitance type humidity sensor can be packaged for use. The assembly mode can be randomly adjusted, and the application is flexible.
In the actual production process, wafer-level preparation can be carried out on wafers with different sizes, the wafers with different sizes are designed according to actual requirements, the wafers can be cut into single chips through modes of grinding wheel scribing or laser scribing and the like after the preparation of the wafers is completed, the single chips are assembled into corresponding test circuit boards respectively, two electrode leading-out ends of the upper surface and the lower surface of a substrate are shared and are respectively led out to the same circuit input end or output end of the circuit board, and the double-sided capacitive humidity sensor is connected with the corresponding chips.
Wherein, external lead, welding pin or flip-chip bonding are located the two sides of two-sided electric capacity type humidity transducer.
Further, the double-sided capacitive humidity sensor of various configurations in embodiments 1 to 5 can be selected according to the application requirements. For example, when a higher capacitance value is required, the double-sided sandwich type humidity sensor of embodiment 4 can be used, and meanwhile, within a required chip size range, the effective electrode area and the humidity sensing area of the double-sided capacitive type humidity sensor are reasonably designed, and the two double-sided capacitive type humidity sensors are electrically connected to the circuit board in series, so that a double-capacitance value of a conventional capacitor can be acquired, a larger electric signal is obtained, the sensitivity is also improved, and the humidity change can be more conveniently detected.
For example, when a low capacitance value is required, the two-sided interdigital capacitive humidity sensor of embodiment 1 may be used, and the two-sided capacitive humidity sensors are electrically connected in parallel, so that a quarter capacitance value of a conventional capacitor can be acquired, the capacitance value is reduced by 4 times, and an electrical signal under a condition of an extremely low capacitance value can be acquired.
According to the use requirements of users, the design and the size of the structures of the upper surface and the lower surface of the substrate can be adjusted in sequence, so that electric signal values with different sizes can be obtained, and the method is suitable for different application scenes; if larger or smaller capacitance values are needed, a plurality of double-sided capacitance type humidity sensors can be connected in series and in parallel to adjust the capacitance values.
The series-parallel connection realization mode of the single double-sided capacitance type humidity sensor comprises the following steps: the circuit board can be designed in a matching mode, after two electrodes of a single double-sided capacitive humidity sensor are respectively bonded and led out of the circuit board, the serial double-sided capacitive humidity sensor or the parallel double-sided capacitive humidity sensor is achieved through series-parallel connection of circuits. It can also be achieved by a via or sidewall sputtering process.
The plurality of double-sided capacitive humidity sensors can be connected in series and/or in parallel in the above mode, and multi-stage series-parallel connection among the plurality of double-sided capacitive humidity sensors is achieved.
The double-sided capacitive humidity sensor can detect air humidity change on double sides, is high in humidity sensitivity and wide in detection space range, two or more double-sided capacitive humidity sensors can be connected in series on the same substrate, the multiple double-sided capacitive humidity sensors can be connected in series or in parallel, the double-sided capacitive humidity sensors with different structures can be selected for combined design according to capacity requirements, the humidity sensitive capacity value can be greatly improved, the design requirements of different capacity values can be met, and the double-sided capacitive humidity sensor is flexible to apply. The double-sided capacitance type humidity sensor can achieve a wider capacitance value adjusting range under the condition that the area of a chip is unchanged, and is suitable for various application environments.
In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings, which are merely for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be construed as limiting the invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the invention, the meaning of "a plurality" is two or more unless otherwise specified.
In the description of the invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted", "connected" and "connected" are to be construed broadly, e.g. as being fixed or detachable or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the creation of the present invention can be understood by those of ordinary skill in the art through specific situations.
It is to be noted that "comprising" in the present invention means that it may include other components in addition to the components described, and the "comprising" may be replaced with "being" or "consisting of … …" in a closed manner.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (10)
1. A double-sided capacitive humidity sensor is characterized by comprising a substrate (1), a first electrode layer (2), a first humidity sensing layer (3), a second electrode layer (4) and a second humidity sensing layer (6);
the first electrode layer (2) and the second electrode layer (4) are respectively connected with two sides of the substrate (1), the first humidity sensing layer (3) covers the first electrode layer (2), and the second humidity sensing layer (6) covers the second electrode layer (4).
2. The double-sided capacitive humidity sensor according to claim 1, wherein the first humidity sensing layer (3) is further covered with a third electrode layer (5).
3. The double-sided capacitive humidity sensor of claim 2 wherein the second humidity sensing layer (6) is further covered with a fourth electrode layer (7).
4. The double-sided capacitive humidity sensor according to claim 3, wherein the first electrode layer (2) and the second electrode layer (4) are interdigital electrode layers, double electrode layers, or single electrode layers.
5. The double-sided capacitive humidity sensor according to claim 4, wherein the third electrode layer (5) and the fourth electrode layer (7) are single electrode layers.
6. The double-sided capacitive humidity sensor according to any of claims 1 to 5, wherein the substrate (1) is a ceramic, glass or silicon wafer.
7. A method of manufacturing a double sided capacitive humidity sensor as claimed in any of claims 1 to 6 comprising the steps of:
s1, taking the substrate (1), photoetching one surface of the substrate (1), cleaning, uniformly coating photoresist, prebaking, exposing and developing to obtain a photoresist pattern;
s2, depositing an electrode metal film on one surface of the substrate (1), soaking the electrode metal film in stripping liquid, and stripping the metal outside the photoresist pattern to obtain a first electrode layer (2);
s3, smearing the polyamic acid solution on the first electrode layer (2) in the step S2, and pre-curing to obtain a cured layer;
s4, photoetching the solidified layer obtained in the step S3, directly and uniformly coating photoresist on the solidified layer, prebaking, exposing and developing to obtain a solidified layer pattern, carrying out wet etching, and carrying out imidization to obtain a first humidity-sensitive layer (3);
s5, repeating the steps S1-S4 on the other side of the substrate (1) to obtain the double-sided capacitance type humidity sensor.
8. The method of claim 7, further comprising the steps of:
s6, depositing an electrode metal film on the first humidity-sensing layer (3) obtained in the step S4, photoetching, uniformly coating photoresist, prebaking, exposing and developing to obtain an electrode metal film pattern;
and S7, carrying out wet etching on the electrode metal film pattern obtained in the step S6 to obtain a third electrode layer (5).
9. The method of claim 7, wherein the temperature of the pre-baking is 80-110 ℃, the time of the exposure is 5-8S, and the time of the development is 6-15S in steps S1 and S4.
10. The method according to claim 7, wherein in step S3, the temperature of the pre-curing is 70-120 ℃ for 20-50 min; in step S4, the imidization is performed by taking a gradient of 20-40 ℃ from 100 ℃ and keeping the temperature for 3-5h, wherein each gradient is separated by 20-40min, and the temperature is increased to 300 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110743766.9A CN113311031A (en) | 2021-07-01 | 2021-07-01 | Double-sided capacitive humidity sensor and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110743766.9A CN113311031A (en) | 2021-07-01 | 2021-07-01 | Double-sided capacitive humidity sensor and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113311031A true CN113311031A (en) | 2021-08-27 |
Family
ID=77381597
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110743766.9A Pending CN113311031A (en) | 2021-07-01 | 2021-07-01 | Double-sided capacitive humidity sensor and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113311031A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115980148A (en) * | 2023-03-22 | 2023-04-18 | 深圳一代科技有限公司 | Double electric layer capacitive thin film sensor and related product, device and method |
-
2021
- 2021-07-01 CN CN202110743766.9A patent/CN113311031A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115980148A (en) * | 2023-03-22 | 2023-04-18 | 深圳一代科技有限公司 | Double electric layer capacitive thin film sensor and related product, device and method |
| CN115980148B (en) * | 2023-03-22 | 2023-06-09 | 深圳一代科技有限公司 | Double-electric-layer capacitive thin film sensor and related products, devices and methods |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104034454B (en) | A kind of sensor chip for many physical quantities and preparation method thereof | |
| Jeong et al. | Liquid alloy printing of microfluidic stretchable electronics | |
| CN106568539A (en) | Polymer substrate-based monolithic integrated temperature and humidity flexible sensor and preparation method | |
| CN105928567B (en) | Silicon substrate gas sensitization chip of integrated Temperature Humidity Sensor and preparation method thereof | |
| CN1845327A (en) | Single slice integration temperature, humidity, pressure sensor chip based on polymer material | |
| CN103376279B (en) | Humidity sensor apparatus | |
| CN104914138A (en) | Humidity sensor, humidity sensor array and preparation method thereof | |
| CN107290241B (en) | QCM humidity sensor and preparation method thereof | |
| CN107966481B (en) | A kind of Material Identification sensor and preparation method thereof based on composite capacitive structure | |
| EP1434048A1 (en) | CAPACITIVE HUMIDITY−SENSOR AND CAPACITIVE HUMIDITY−SENSOR MANUFACTURING METHOD | |
| CN111398364A (en) | High-selectivity array MOS sensor and preparation method thereof | |
| WO2018209923A1 (en) | Clotting test paper and method for preparing piezoelectric sensor chip thereof | |
| CN113311031A (en) | Double-sided capacitive humidity sensor and preparation method thereof | |
| CN111044583A (en) | Humidity sensor chip | |
| CN106093138A (en) | By manufacture method and the sensor of the sensor of metal-oxide detected gas | |
| CN112881481A (en) | High-performance humidity sensor and preparation method thereof | |
| KR20080002874A (en) | Characterization technique for dielectric properties of polymers | |
| CN1043987A (en) | A kind of warm and humid difunctional sensitive film element and manufacture method thereof | |
| CN215066315U (en) | Double-sided capacitive humidity sensor | |
| CN103149135B (en) | Cell suspension concentration sensor | |
| CN107748184B (en) | Humidity sensor and preparation method thereof | |
| CN205280640U (en) | Capacitive humidity sensor | |
| CN105486728A (en) | Capacitive humidity sensor and manufacturing method thereof | |
| CN110702747B (en) | Diaminoanthraquinone squaramide polymer, humidity-sensitive sensor based on squaramide polymer and preparation method of humidity-sensitive sensor | |
| CN111007107A (en) | Dew point measuring method based on carbon-based flexible humidity-sensitive device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |