CN117539366A - Capacitive detection structure and electronic equipment - Google Patents

Capacitive detection structure and electronic equipment Download PDF

Info

Publication number
CN117539366A
CN117539366A CN202410033215.7A CN202410033215A CN117539366A CN 117539366 A CN117539366 A CN 117539366A CN 202410033215 A CN202410033215 A CN 202410033215A CN 117539366 A CN117539366 A CN 117539366A
Authority
CN
China
Prior art keywords
circuit board
plate
facing
cover plate
conductive sheet
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
Application number
CN202410033215.7A
Other languages
Chinese (zh)
Inventor
吴奕斌
刘柯佳
夏波
张耀国
聂波
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jige Semiconductor Ningbo Co ltd
Original Assignee
Jige Semiconductor Ningbo Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Jige Semiconductor Ningbo Co ltd filed Critical Jige Semiconductor Ningbo Co ltd
Priority to CN202410033215.7A priority Critical patent/CN117539366A/en
Publication of CN117539366A publication Critical patent/CN117539366A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/0414—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means using force sensing means to determine a position
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/0416—Control or interface arrangements specially adapted for digitisers
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2203/00—Indexing scheme relating to G06F3/00 - G06F3/048
    • G06F2203/041—Indexing scheme relating to G06F3/041 - G06F3/045
    • G06F2203/04105—Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Human Computer Interaction (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

The embodiment of the disclosure provides a capacitive detection structure and an electronic device, comprising: the device comprises a base and a cover plate positioned right above the base, wherein the base is spaced from the cover plate, and the cover plate bears pressure; the circuit board is positioned on one surface of the cover plate facing the base; the conductive sheet is positioned on the surface of the base facing the cover plate; the circuit board is provided with a conductive sheet, two polar plates are arranged on the surface of the circuit board facing the conductive sheet, and a capacitance value between the two polar plates changes along with the pressure applied to the cover plate. According to a calculation formula of the capacitor, dielectric constant, electrode plate area or relative area of the electrode plates and interval distance between the electrode plates are three variables which cause capacitance value change.

Description

Capacitive detection structure and electronic equipment
Technical Field
The embodiment of the disclosure relates to the technical field of pressure testing, in particular to a capacitive detection structure and electronic equipment.
Background
A touch panel is a type of touch sensing input device that is now widely used. In the field of touch pads, consumers have not been satisfied with simple touch operations, and the demand for pressure detection is also increasing. Many pressure detection schemes, such as a capacitance scheme, an inductance scheme, a strain gauge scheme, a pressure film scheme, and the like, are currently emerging. The capacitance detection scheme is widely applied due to the characteristics of low cost, high precision, high reliability and the like.
In the current capacitive detection scheme, two electrode plates of a capacitor are respectively located below a touch panel and on a fixed support. When the surface of the touch pad is pressed, downward tiny displacement is generated, the distance between the capacitance polar plates is changed, and then the capacitance between the two polar plates is changed. By detecting the change in capacitance, the pressure experienced by the touch pad can be measured.
According to the calculation formulas of the capacitance and the pressure, the dielectric constant, the polar plate area or the relative area of the polar plates and the interval distance between the polar plates can cause the change of the capacitance value, so that the relation between the pressure and the capacitance is nonlinear in the pressure detection process, and the subsequent signal processing process is difficult.
Disclosure of Invention
The embodiment of the disclosure provides a capacitive detection structure and electronic equipment, which are at least beneficial to solving the problem that the relation between pressure and capacitance is nonlinear in the pressure detection process.
According to some embodiments of the present disclosure, an aspect of an embodiment of the present disclosure provides a capacitive detection structure, including: the device comprises a base and a cover plate positioned right above the base, wherein the base is spaced from the cover plate, and the cover plate is used for bearing pressure; the circuit board is positioned on one surface of the cover plate, which faces the base; the conductive sheet is positioned on the surface of the base, which faces the cover plate; and a positive area is arranged between the two polar plates, wherein at least one polar plate is positioned on the surface of the circuit board facing the conducting strip, and the capacitance value between the two polar plates changes along with the pressure applied to the cover plate.
In some embodiments, one of the plates is located on a surface of the circuit board facing the conductive sheet, and the other plate is located on a surface of the conductive sheet facing the circuit board; wherein, two polar plates are oppositely arranged in the direction vertical to the surface of the circuit board.
In some embodiments, the facing region has a width of 2mm to 50mm along a direction parallel to the surface of the circuit board.
In some embodiments, the thickness of the plate is 0.01 mm-1 mm.
In some embodiments, one of the plates is located on a surface of the circuit board facing the conductive sheet, and the other plate is located on a surface of the conductive sheet facing the circuit board; the polar plate positioned on the surface of the circuit board facing the conducting strip is provided with a hollow along the cross section shape parallel to the circuit board, and the area of the polar plate positioned on the surface of the conducting strip facing the circuit board along the cross section parallel to the circuit board is smaller than the hollow.
In some embodiments, further comprising: the conductive block is positioned on the surface of the conductive sheet facing the circuit board; the two polar plates are located on the surface, facing the conducting strip, of the circuit board, and the conducting block is located in the orthographic projection of the opposite area of the conducting strip.
In some embodiments, the thickness of the conductive sheet is 0.05 mm-3 mm.
In some embodiments, further comprising: the two cantilever structures are respectively and fixedly connected to two opposite ends of one surface of the circuit board, which is far away from the cover plate; the two gaskets are respectively arranged between the cantilever beam and the circuit board.
In some embodiments, further comprising: the shielding layer is arranged in the circuit board; wherein, the cross-sectional area of shielding layer is the same as the cross-sectional area of circuit board.
In some embodiments, the shielding layer is provided as a grounded copper sheet.
According to some embodiments of the present disclosure, another aspect of embodiments of the present disclosure further provides an electronic device, including: a capacitive sensing structure as described above; and the processor is configured to acquire the capacitance value variation when the cover plate is subjected to pressure and detect the pressure applied to the cover plate based on the capacitance value variation.
The technical scheme provided by the embodiment of the disclosure has at least the following advantages:
the technical scheme of the capacitive detection structure provided by the embodiment of the disclosure comprises a base and a cover plate positioned right above the base, wherein the base is spaced from the cover plate, and the cover plate is used for bearing pressure; the circuit board is positioned on one surface of the cover plate, which faces the base; the conductive sheet is positioned on the surface of the base, which faces the cover plate; and a positive area is arranged between the two polar plates, wherein at least one polar plate is positioned on the surface of the circuit board facing the conducting strip, and the capacitance value between the two polar plates changes along with the pressure applied to the cover plate. According to a calculation formula of the capacitor, dielectric permittivity, electrode plate area or relative area of the electrode plates and interval distance between the electrode plates are three variables which cause capacitance value change.
Drawings
One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, which are not to be construed as limiting the embodiments unless specifically indicated otherwise; in order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the conventional technology, the drawings required for the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present disclosure, and other drawings may be obtained according to these drawings without inventive effort to those of ordinary skill in the art.
FIG. 1 is a schematic diagram of a capacitive sensing structure;
FIG. 2 is a graph showing the change in distance between plates when the cover plate of FIG. 1 is subjected to pressure;
fig. 3 is a schematic structural diagram of a capacitive detection structure according to an embodiment of the disclosure;
FIG. 4 is an elevation view of the relative area change between the two plates of FIG. 3 when the cover plate is under pressure;
FIG. 5 is a left side view of the bipolar plate of FIG. 3 when the cover is not under pressure;
FIG. 6 is a schematic illustration of another capacitive sensing structure provided in accordance with an embodiment of the present disclosure;
FIG. 7 is a cross-sectional view of the bipolar plate of FIG. 6;
FIG. 8 is a top view of the bipolar plate of FIG. 6;
FIG. 9 is a schematic diagram of a further capacitive sensing apparatus provided in accordance with an embodiment of the present disclosure;
FIG. 10 is an elevation view of the change in the separation distance between the plates of FIG. 9 when the cover plate is under pressure;
fig. 11 is a left side view of the bipolar plate and conductive sheet of fig. 9 when the cover plate is not under pressure.
Detailed Description
As known from the background art, in the current capacitive detection structure, the relationship between the pressure and the capacitance is nonlinear in the pressure detection process.
Fig. 1 is a schematic structural diagram of a capacitive sensing structure. Referring to fig. 1, it is found by analysis that one of the reasons why the manufacturing cost of the present capacitive sensing structure is too high is that, since the capacitive sensing structure detects the change of the capacitance value between two oppositely disposed plates, and thus detects the pressure value received by the cover plate 103, it is generally required that the flexible Circuit board 102 (FPC, flexiblePrinted Circuit) or the wire form the two plates into one capacitive structure. Specifically, the two polar plates include a first polar plate 104 and a second polar plate 105, the base 101 and the cover plate 103 are arranged at intervals, the first circuit board is located on one surface of the cover plate 103 facing the base 101, the first polar plate 104 is set as copper exposure on the circuit board 102, the second polar plate 105 is located on one surface of the base 101 facing the circuit board 102, in order to form a capacitance structure between the first polar plate 104 and the second polar plate 105, the second polar plate 105 needs to be electrically connected to the first circuit board through an FPC or a wire, or a second circuit board is set, the second polar plate 105 is set as copper exposure on the second circuit board, and then the second circuit board is electrically connected to the circuit board 102 through the FPC or the wire.
Fig. 2 is a graph of the change in distance between plates when the cover plate of fig. 1 is subjected to pressure.
Referring to fig. 2, when the cover plate 103 is pressed, the distance between the first electrode plate 104 and the second electrode plate 105 becomes smaller. When the cover plate 103 is not under pressure, the capacitance between the first polar plate 104 and the second polar plate 105 is calculated as:
1 (1)
Wherein,for dielectric permittivity, S is the area of the first plate 104, and d is the vertical distance between the first plate 104 and the second plate 105.
When the cover plate 103 is pressed, the distance between the first polar plate 104 and the second polar plate 105 becomes smaller, and at this time, the capacitance calculation formula between the first polar plate 104 and the second polar plate 105 is as follows:
2, 2
Wherein,for dielectric permittivity, S is the first plate area, ">Is perpendicular between the first polar plate and the second polar plate when the cover plate is pressedDistance.
Further, according to the mechanical calculation formula, the pressure applied to the cover 103 is:
3
Wherein,is the rigidity coefficient of the capacitive detection structure in the vertical direction.
As can be seen from equations 1, 2 and 3, the amount of change in the vertical distance between the first electrode plate 104 and the second electrode plate 105 and the pressure applied to the cover plate 103 are calculated by detecting the amount of change in the capacitance between the first electrode plate 104 and the second electrode plate 105, and the pressure applied to the cover plate 103 is calculated.
According to the capacitance type detecting structure shown in fig. 1, when the cover plate 103 is pressed, the vertical distance between the first electrode plate 104 and the second electrode plate 105 is changed, so that the capacitance between the first electrode plate 104 and the second electrode plate 105 is changed, and the capacitance change amount between the first electrode plate 104 and the second electrode plate 105 is:
4. The method is to
Meanwhile, as can be seen from the combination of the formulas 3 and 4, in the capacitive detection structure shown in fig. 1, in the process of capacitance change along with pressure, the relationship between the pressure and the capacitance change amount is a nonlinear relationship, so that the subsequent signal processing process is difficult.
The embodiment of the disclosure provides a capacitive detection structure and electronic equipment, which are at least beneficial to solving the problem that the relation between pressure and capacitance is nonlinear in the pressure detection process.
Embodiments of the present disclosure will be described in detail below with reference to the attached drawings. However, those of ordinary skill in the art will understand that in the various embodiments of the present disclosure, numerous technical details have been set forth in order to provide a better understanding of the present disclosure. However, the technical solutions claimed in the present disclosure can be implemented without these technical details and with various changes and modifications based on the following embodiments.
Fig. 3 is a schematic structural diagram of a capacitive detection structure according to an embodiment of the disclosure.
Referring to fig. 3, a capacitive detection structure provided in an embodiment of the present disclosure includes: a base 201 and a cover plate 203 located right above the base 201, the base 201 is spaced from the cover plate 203, and the cover plate 203 is used for bearing pressure; the circuit board 202, the circuit board 202 locates at one side facing the base 201 of the cover 203; a conductive sheet 206, wherein the conductive sheet 206 is located on the surface of the base 201 facing the cover 203; the two plates have opposite areas therebetween, wherein at least one plate is located on the surface of the circuit board 202 facing the conductive sheet 206, and the capacitance value between the two plates changes as the cover plate 203 is pressed.
Specifically, the two electrode plates are a first electrode plate 204 and a second electrode plate 205, where the first electrode plate 204 is located on a surface of the circuit board 202 facing the conductive sheet 206, the second electrode plate 205 is located on a surface of the conductive sheet 206 facing the circuit board 202, and a facing area is located between the two electrode plates, and when the cover plate 203 is pressed, the first electrode plate 204 is driven to move in a direction toward the metal sheet, and a relative area between the first electrode plate 204 and the second electrode plate 205 is increased, but a vertical separation distance between the first electrode plate 204 and the second electrode plate 205 and a dielectric permittivity of a medium are not changed. Therefore, according to the calculation formula of the pressure and the capacitance, the relationship between the pressure and the capacitance is in a linear relationship in the process that the cover plate 203 is subjected to the pressure, so that the calculation process of the subsequent signal processing is simpler and more convenient.
In some other embodiments, the first electrode plate 204 and the second electrode plate 205 are both located on the surface of the circuit board 202 facing the conductive sheet 206, the first electrode plate 204 and the second electrode plate 205 are disposed opposite to each other, a facing area is located between the first electrode plate 204 and the second electrode plate 205, a conductive bump 209 is disposed on the surface of the conductive sheet 206 facing the circuit board 202, and the conductive bump 209 is located in the orthographic projection of the facing area on the conductive sheet 206. When the cover plate 203 is pressed, the first polar plate 204 and the second polar plate 205 are driven to move towards the direction of the metal sheet, and as the conductive block 209 is positioned in the orthographic projection of the opposite area on the conductive sheet 206, the conductive block 209 enters the opposite area, so that the vertical interval distance between the first polar plate 204 and the second polar plate 205 is changed, but the relative area of the first polar plate 204 and the second polar plate 205 and the dielectric constant of the medium are not changed. According to the calculation formula of the pressure and the capacitance, the relationship between the pressure and the capacitance is still in a linear relationship in the process that the cover plate 203 is subjected to the pressure, so that convenience is brought to the calculation process of subsequent signal processing.
Fig. 4 is a front view showing the relative area change between the plates when the cover 203 of fig. 3 is pressurized. Fig. 5 is a left side view of the bipolar plate of fig. 3 when the cover 203 is not under pressure.
Referring to fig. 3, 4 and 5, the first electrode plate 204 is located on the surface of the circuit board 202 facing the conductive sheet 206, the second electrode plate 205 is located on the surface of the conductive sheet 206 facing the circuit board 202, the two electrode plates are opposite to each other in a direction perpendicular to the surface of the circuit board 202, and a facing area is formed between the two electrode plates, when the cover plate 203 is pressed, the first electrode plate 204 is driven to move in a direction facing the metal sheet, and the relative area of the first electrode plate 204 and the second electrode plate 205 is increased.
Referring to fig. 4 and 5, when the cover 203 is pressed, the relative area of the first plate 204 and the second plate 205 increases. When the cover 203 is not pressed, the capacitance between the first electrode plate 204 and the second electrode plate 205 is calculated as:
5. The method is to
Wherein,l is the length of the first polar plate and is the dielectric constant of the medium>The length of the facing area between the first plate 204 and the second plate 205 when the cover is not under pressure is d the vertical distance between the first plate 204 and the second plate 205.
When the cover 203 is pressed, the relative area of the first electrode plate 204 and the second electrode plate 205 becomes larger, and the capacitance between the first electrode plate 204 and the second electrode plate 205 is calculated as:
6. The method is to
Wherein,for dielectric permittivity, S is the first plate area, ">The length of the facing area between the first plate 204 and the second plate 205 when the cover is pressed is d, the vertical distance between the first plate 204 and the second plate 205.
Further, according to the mechanical calculation formula, the pressure applied to the cover 203 is:
7. The method of the invention
Wherein,is the rigidity coefficient of the capacitive detection structure in the vertical direction.
According to the capacitive sensing structure shown in fig. 1, when the cover 203 is pressed, the relative area between the first plate 204 and the second plate 205 changes, so that the capacitance between the first plate 204 and the second plate 205 changes, and the capacitance between the first plate 204 and the second plate 205 changes by the following amounts:
8. The method is used for preparing the product
As can be obtained from the formulas 7 and 8,
9. The invention is applicable to
That is, in the capacitive detection structure shown in fig. 3, in the process of capacitance change along with pressure, the relationship between the pressure and the capacitance change amount is in a linear relationship, so that the calculation process of subsequent signal processing is simpler and more convenient.
In the embodiment of the present disclosure, the width of the facing area along the direction parallel to the surface of the circuit board 202 is 2mm to 50mm. Specifically, the thickness of the material can be 2 mm-10 mm, 10 mm-18 mm, 18 mm-26 mm, 26 mm-34 mm, 34 mm-42 mm or 42 mm-50 mm. During the compression of the cover 203, the facing area does not change along the width parallel to the surface of the circuit board 202, i.e., the vertical separation distance between the first plate 204 and the second plate 205 does not change. In this range, since the first electrode plate 204 is pressed down along with the cover plate 203 in the process that the cover plate 203 is pressed down, a certain interval distance is provided between the first electrode plate 204 and the second electrode plate 205 to ensure that the facing areas of the first electrode plate 204 and the second electrode plate 205 are changed to a certain extent, so that the capacitance is changed, and meanwhile, the first electrode plate 204 and the second electrode plate 205 are not contacted with each other, so that a short circuit of the capacitance structure is caused, and the performance of the capacitance structure is ensured.
In the embodiment of the disclosure, the thickness of the polar plate is 0.01 mm-1 mm. The method can be 0.01 mm-0.05 mm, 0.05 mm-0.1 mm, 0.1 mm-0.15 mm, 0.15 mm-0.2 mm, 0.2 mm-0.25 mm, 0.25 mm-0.3 mm, 0.3 mm-0.35 mm, 0.35 mm-0.4 mm, 0.4 mm-0.45 mm, 0.45 mm-0.5 mm, 0.5 mm-0.55 mm, 0.55 mm-0.6 mm, 0.65 mm-0.7 mm, 0.7 mm-0.75 mm, 0.75 mm-0.8 mm, 0.8 mm-0.85 mm, 0.85 mm-0.9 mm, 0.9 mm-0.95 mm or 0.95 mm-1 mm. In this thickness range, on the one hand, a lightweight capacitive sensing structure is advantageously formed, and in the case of providing a thinner plate, the pressure applied to the cover plate 203 by sensing the capacitance change can be satisfied.
In the embodiment of the present disclosure, the first electrode plate 204 and the second electrode plate 205 may be both metal electrode plates, where one metal electrode plate is disposed on a surface of the circuit board 202 facing the conductive sheet 206, and the other metal electrode plate is disposed on a surface of the conductive sheet 206 facing the circuit board 202.
Fig. 6 is a schematic diagram of another capacitive sensing structure according to an embodiment of the disclosure. Fig. 7 is a cross-sectional view of the bipolar plate of fig. 6. Fig. 8 is a top view of the bipolar plate of fig. 6.
Referring to fig. 6, 7 and 8, one of the electrode plates is located on the surface of the circuit board 202 facing the conductive sheet 206, and the other electrode plate is located on the surface of the conductive sheet 206 facing the circuit board 202; wherein the plate on the surface of the circuit board 202 facing the conductive sheet 206 has a hollow shape along a cross-sectional shape parallel to the circuit board 202, and the plate on the surface of the conductive sheet 206 facing the circuit board 202 has a smaller cross-sectional area parallel to the circuit board 202 than the hollow shape. When the cover plate 203 is pressed, the first polar plate 204 is driven to move towards the direction of the metal sheet, the second polar plate 205 enters the hollow, and the relative area of the first polar plate 204 and the second polar plate 205 changes.
In the embodiment of the disclosure, the first polar plate 204 may be configured as an annular polar plate, the second polar plate 205 may be configured as a cylindrical polar plate, and when the annular polar plate is driven to move toward the direction of the metal sheet, the cylindrical polar plate passes through the hollow, the relative area between the annular polar plate and the cylindrical polar plate changes, and the capacitance between the two polar plates changes. In some other embodiments, the hollow may be rectangular or irregularly shaped, as long as the second electrode plate 205 may pass through the hollow and no contact occurs between the second electrode plate 205 and the first electrode plate 204, which is not limited herein.
It should be noted that, the embodiment of the capacitive detection structure provided in fig. 6 corresponds to the embodiment of the capacitive detection structure provided in fig. 3, and the specific implementation details and technical effects thereof are similar to or the same as those of the embodiment of the capacitive detection structure provided in fig. 3, and are not repeated herein.
In the above embodiment, the thickness of the conductive sheet 206 may be set to 0.05mm to 3mm. Specifically, the thickness of the material can be 0.05 mm-0.55 mm, 0.55 mm-1.05 mm, 1.05 mm-1.55 mm, 1.55 mm-2.05 mm, 2.05 mm-2.55 mm or 2.55 mm-3 mm. In this thickness range, the thickness of the conductive sheet 206 is not too small, so that on one hand, the adjustment performance of the conductive sheet 206 for the electric field between the first polar plate 204 and the second polar plate 205 can be ensured, and a capacitance structure is formed between the first polar plate 204 and the second polar plate 205. On the other hand, in the process that the cover plate 203 is pressed down by pressure, the interval distance between the first polar plate 204 and the conductive sheet 206 is gradually reduced, the conductive sheet 206 is set within the thickness range, the thickness of the conductive sheet 206 is not too large, a certain interval space can be reserved between the first polar plate 204 and the conductive sheet 206, and the short circuit of the capacitor structure caused by the contact between the first polar plate 204 and the conductive sheet 206 is prevented. In some other embodiments of the present disclosure, an insulating layer may be provided on the surfaces of the first and second electrode plates 204 and 205 or the surface of the conductive sheet 206.
Fig. 9 is a schematic diagram of another capacitive sensing apparatus according to an embodiment of the present disclosure.
Referring to fig. 9, the capacitive detection structure further includes: a conductive block 209, the conductive block 209 being located on a surface of the conductive sheet 206 facing the circuit board 202; wherein, both electrode plates are positioned on the surface of the circuit board 202 facing the conductive sheet 206, and the conductive block 209 is positioned in the orthographic projection of the facing area on the conductive sheet 206.
In the embodiment of the disclosure, the first electrode plate 204 and the second electrode plate 205 are both located on the surface of the circuit board 202 facing the conductive sheet 206, the first electrode plate 204 and the second electrode plate 205 are disposed opposite to each other, an opposite area is located between the first electrode plate 204 and the second electrode plate 205, a conductive block 209 is disposed on the surface of the conductive sheet 206 facing the circuit board 202, and the conductive block 209 is located in the orthographic projection of the opposite area on the conductive sheet 206. When the cover plate 203 is pressed, the first polar plate 204 and the second polar plate 205 are driven to move towards the direction of the metal sheet, and as the conductive block 209 is positioned in the orthographic projection of the opposite area on the conductive sheet 206, the part of the conductive block 209 entering the opposite area is lengthened, so that the vertical interval distance between the first polar plate 204 and the second polar plate 205 is changed, but the relative area of the first polar plate 204 and the second polar plate 205 and the dielectric constant of the medium are not changed. According to the calculation formula of the pressure and the capacitance, the relationship between the pressure and the capacitance is still in a linear relationship in the process that the cover plate 203 is subjected to the pressure, so that convenience is brought to the calculation process of subsequent signal processing.
Fig. 10 is a front view showing the change of the distance between the two plates when the cover plate 203 in fig. 9 is pressed. Fig. 11 is a left side view of the bipolar plate and conductive sheet 206 of fig. 9 with the cover 203 not under pressure.
As can be seen from fig. 9, 10 and 11, when the cover 203 is pressed, the first plate 204 and the second plate 205 are both driven to move toward the metal sheet, and the conductive block 209 enters the facing area, so that the vertical separation distance between the first plate 204 and the second plate 205 is changed. The capacitance between the first plate 204 and the second plate 205 is equivalent to the capacitance of the portion of the conductive bump 209 that enters the facing region and the capacitance of the portion of the conductive bump 209 that does not enter the facing region are connected in series.
Specifically, when the cover 203 is not under pressure, the capacitance between the first plate 204 and the second plate 205 is calculated as:
10. The method of the invention
Wherein,l is the length of the first polar plate and is the dielectric constant of the medium>For the length of the part of the conductive block 209 that enters the facing area when the cover 203 is not under pressure, +.>For the vertical distance between the first plate 204 and the second plate 205>Is the width of the conductive block.
When the cover 203 is not under pressure, the capacitance between the first plate 204 and the second plate 205 is calculated as:
11. The method of the invention
Wherein,l is the length of the first polar plate and is the dielectric constant of the medium>For the length of the part of the conductive block 209 that enters the facing area when the cover 203 is pressed, +.>For the vertical distance between the first plate 204 and the second plate 205>Is the width of the conductive block.
Further, according to the mechanical calculation formula, the pressure applied to the cover 203 is:
12. Fig.
Wherein,is the rigidity coefficient of the capacitive detection structure in the vertical direction.
According to the capacitance type detecting structure shown in fig. 9, when the cover 203 is pressed, the vertical distance between the first plate 204 and the second plate 205 is changed, so that the capacitance between the first plate 204 and the second plate 205 is changed, and the capacitance change amount between the first plate 204 and the second plate 205 is:
13 of the group
As can be obtained from the formulas 7 and 8,
14, of the order of magnitude
That is, in the capacitive detection structure shown in fig. 9, in the process of capacitance change along with pressure, the relationship between the pressure and the capacitance change amount is in a linear relationship, so that the calculation process of the subsequent signal processing is simpler and more convenient.
In the embodiment of the present disclosure, the width of the conductive block 209 is 2mm to 50mm. Specifically, the thickness of the material can be 2 mm-10 mm, 10 mm-18 mm, 18 mm-26 mm, 26 mm-34 mm, 34 mm-42 mm or 42 mm-50 mm. Within this width, the conductive bump 209 is prevented from contacting the first plate 204 or the second plate 205 when entering the facing region, resulting in a short circuit of the capacitor structure.
In the above embodiment, the capacitive detection structure further includes: two cantilever structures 208, the two cantilever structures 208 are respectively and fixedly connected to two opposite ends of one surface of the circuit board 202 away from the cover plate 203; two pads 207, the two pads 207 are respectively disposed between the cantilever beam and the circuit board 202.
Specifically, the two cantilever structures 208 support the weights of the circuit board 202, the cover 203, the first electrode plate 204 and the second electrode plate 205, so that the circuit board 202, the cover 203, the first electrode plate 204 and the second electrode plate 205 are fixed to an external structure, and when the cover 203 is pressed, the pressure bearing capacity and durability of the whole capacitive detection structure are improved.
In some other embodiments, the cantilever structure 208 may be slidably connected to an external structure, where the cantilever structure 208 may drive the circuit board 202, the cover 203, the first electrode plate 204, and the second electrode plate 205 to be slidably connected to the external structure, and the vertical separation distance between the first electrode plate 204, the second electrode plate 205, and the conductive sheet 206 may be slidably adjusted according to the magnitude of the pressure applied to the cover 203, so as to ensure the detection effect of the capacitive detection structure.
Two pads 207 are respectively disposed between the two cantilever structures 208 and the circuit board 202 to provide a space between the first and second electrode plates 204, 205 and the conductive sheet 206, so that capacitance structures are respectively formed between the first and second electrode plates 204, 205 and the conductive sheet 206.
The thickness of the spacer 207 may be 0.3mm to 2mm, specifically 0.3mm to 0.6mm, 0.6mm to 0.9mm, 0.9mm to 1.2mm, 1.2mm to 1.5mm, 1.5mm to 1.8mm, or 1.8mm to 2.1mm, which is not limited herein. In some embodiments, the pad 207 may be provided as a film layer, or may be formed by stacking film layers with the same thickness or different thicknesses, and the thickness of the pad 207 may be selected according to the needs of the actual capacitive detection structure during the specific application, which is not limited herein.
In the embodiment of the present disclosure, the thickness of the spacer 207 may be set smaller than the length of the first polar plate 204 or the second polar plate 205, so that the overall occupied space of the capacitive detection structure is smaller, and meanwhile, the manufacturing cost of the capacitive detection structure is further saved.
In the above embodiment, the capacitive detection structure further includes: a shielding layer disposed within the circuit board 202; wherein the cross-sectional area of the shielding layer is the same as the cross-sectional area of the circuit board 202.
Specifically, in the detection process, when a conductive medium is used to apply pressure to the cover 203, the conductive medium may interfere with the electric field around the capacitive structure, thereby affecting the capacitive detection structure, because the thickness of the cover 203 and the thickness of the circuit board 202 are relatively thin. A shielding layer is arranged in the electrode plate, so that the influence of the conductive medium on the capacitor structure can be isolated.
Setting the cross-sectional area of the shielding layer to be the same as the cross-sectional area of the circuit board 202 can further improve the shielding ability of the shielding layer to the conductive medium, and facilitate assembly of the capacitive detection structure.
In some embodiments, the shielding layer is provided as a grounded copper sheet.
In particular, the shielding layer may be provided as a grounded copper sheet. The copper sheet has low material cost, convenient manufacture and good conductivity, and the shielding layer is arranged as the grounded copper sheet, so that the manufacturing cost of the capacitive detection structure can be further reduced.
In some other embodiments, the shielding layer may be made of other shielding materials, such as conductive foam, a grounding aluminum sheet, etc., as long as the shielding layer can isolate the conductive medium from influencing the capacitance detection structure, which is not limited herein.
In the technical scheme of the capacitive detection structure provided by the embodiment of the disclosure, the capacitive detection structure comprises a base 201 and a cover plate 203 positioned right above the base 201, wherein the base 201 is spaced from the cover plate 203, and the cover plate 203 is used for bearing pressure; a circuit board 202, wherein the circuit board 202 is located on one surface of the cover plate 203 facing the base 201; a conductive sheet 206, wherein the conductive sheet 206 is located on the surface of the base 201 facing the cover 203; there is a facing area between the two plates, where at least one of the plates is located on a surface of the circuit board 202 facing the conductive sheet 206, and as the cover 203 is pressed, a capacitance value between the two plates changes. According to the calculation formula of the capacitance, dielectric permittivity, electrode plate area or relative area of the electrode plates and interval distance between the electrode plates are three variables which cause capacitance value change.
According to some embodiments of the present disclosure, another aspect of embodiments of the present disclosure further provides an electronic device, including: a capacitive sensing structure as described above; and the processor is configured to acquire the capacitance value variation when the cover plate is subjected to pressure and detect the pressure applied to the cover plate based on the capacitance value variation.
Specifically, the electronic device may be an electronic product with a touch screen, such as a mobile phone, a tablet computer, or a touch screen with a touch interaction display terminal, such as a vending machine, a signal display terminal, etc.
According to the embodiment of the disclosure, when pressure is applied to the cover plate, the capacitance of the capacitance structure formed by the first polar plate, the second polar plate and the conducting strip is detected, the change value of the vertical distance between the first polar plate, the second polar plate and the conducting strip is calculated when the cover plate is not subjected to the pressure and the cover plate is subjected to the pressure, and then the pressure applied to the cover plate is calculated.
It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples of implementing the disclosure, and that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the disclosure, and the scope of the disclosure should therefore be assessed as that of the appended claims.

Claims (11)

1. A capacitive sensing structure, comprising:
the device comprises a base and a cover plate positioned right above the base, wherein the base is spaced from the cover plate, and the cover plate is used for bearing pressure;
the circuit board is positioned on one surface of the cover plate, which faces the base;
the conductive sheet is positioned on the surface of the base, which faces the cover plate;
and a positive area is arranged between the two polar plates, wherein at least one polar plate is positioned on the surface of the circuit board facing the conducting strip, and the capacitance value between the two polar plates changes along with the pressure applied to the cover plate.
2. The capacitive sensing structure of claim 1, wherein one of said plates is located on a surface of said circuit board facing said conductive sheet and the other of said plates is located on a surface of said conductive sheet facing said circuit board; wherein, two polar plates are oppositely arranged in the direction vertical to the surface of the circuit board.
3. The capacitive sensing structure of claim 2, wherein the facing region has a width of 2mm to 50mm along a direction parallel to the surface of the circuit board.
4. The capacitive sensing structure of claim 2, wherein the plate has a thickness of 0.01mm to 1mm.
5. The capacitive sensing structure of claim 1, wherein one of said plates is located on a surface of said circuit board facing said conductive sheet and the other of said plates is located on a surface of said conductive sheet facing said circuit board; the polar plate positioned on the surface of the circuit board facing the conducting strip is provided with a hollow along the cross section shape parallel to the circuit board, and the area of the polar plate positioned on the surface of the conducting strip facing the circuit board along the cross section parallel to the circuit board is smaller than the hollow.
6. The capacitive sensing structure of claim 1, further comprising:
the conductive block is positioned on the surface of the conductive sheet facing the circuit board;
the two polar plates are located on the surface, facing the conducting strip, of the circuit board, and the conducting block is located in the orthographic projection of the opposite area of the conducting strip.
7. The capacitive sensing structure of claim 1, wherein the conductive sheet has a thickness of 0.05mm to 3mm.
8. The capacitive sensing structure of any one of claims 1-7, further comprising:
the two cantilever structures are respectively and fixedly connected to two opposite ends of one surface of the circuit board, which is far away from the cover plate;
the two gaskets are respectively arranged between the cantilever beam and the circuit board.
9. The capacitive sensing structure of any one of claims 1-7, further comprising:
the shielding layer is arranged in the circuit board; wherein, the cross-sectional area of shielding layer is the same as the cross-sectional area of circuit board.
10. The capacitive sensing structure of claim 9, wherein said shielding layer is configured as a grounded copper sheet.
11. An electronic device, comprising: a capacitive sensing structure as claimed in any one of claims 1 to 10; and the processor is configured to acquire the capacitance value variation when the cover plate is subjected to pressure and detect the pressure applied to the cover plate based on the capacitance value variation.
CN202410033215.7A 2024-01-09 2024-01-09 Capacitive detection structure and electronic equipment Pending CN117539366A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202410033215.7A CN117539366A (en) 2024-01-09 2024-01-09 Capacitive detection structure and electronic equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202410033215.7A CN117539366A (en) 2024-01-09 2024-01-09 Capacitive detection structure and electronic equipment

Publications (1)

Publication Number Publication Date
CN117539366A true CN117539366A (en) 2024-02-09

Family

ID=89784655

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202410033215.7A Pending CN117539366A (en) 2024-01-09 2024-01-09 Capacitive detection structure and electronic equipment

Country Status (1)

Country Link
CN (1) CN117539366A (en)

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101832750A (en) * 2010-05-20 2010-09-15 中国海洋大学 Variable dielectric capacitor type sensing device and method for oscillation measurement of piano key rolling reduction
CN103091002A (en) * 2012-01-13 2013-05-08 骏升科技(中国)有限公司 Capacitance type pressure sensing conversion device and method of achieving capacitance type pressure sensing on low-end singlechip
CN103399653A (en) * 2013-07-19 2013-11-20 深圳超多维光电子有限公司 Telescopic device, operating bar and measurement method
CN106708345A (en) * 2017-01-09 2017-05-24 维沃移动通信有限公司 Touch control device and terminal thereof
CN106896970A (en) * 2017-03-15 2017-06-27 上海大学 A kind of touch sensing and preparation method
CN107562237A (en) * 2016-07-01 2018-01-09 南昌欧菲生物识别技术有限公司 Pressure sensitive touch screen
CN107562247A (en) * 2016-07-01 2018-01-09 南昌欧菲光科技有限公司 Touch screen and electronic equipment
US20190131969A1 (en) * 2016-04-22 2019-05-02 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. Elastomer-based Capacitive Control and Operating Element
CN110806223A (en) * 2020-01-08 2020-02-18 腾讯科技（深圳）有限公司 Flexible sensing system, proximity sensing method and device, intelligent robot and equipment
CN112362199A (en) * 2020-10-30 2021-02-12 华中科技大学 Medium insertion type capacitive pressure sensor and preparation method thereof
CN113551811A (en) * 2021-08-16 2021-10-26 吉林大学 Design method of 4D printed multifunctional touch sensor
CN219829751U (en) * 2023-05-29 2023-10-13 浙江舜为科技有限公司 Micro distance detection device and near-to-eye display device

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101832750A (en) * 2010-05-20 2010-09-15 中国海洋大学 Variable dielectric capacitor type sensing device and method for oscillation measurement of piano key rolling reduction
CN103091002A (en) * 2012-01-13 2013-05-08 骏升科技(中国)有限公司 Capacitance type pressure sensing conversion device and method of achieving capacitance type pressure sensing on low-end singlechip
CN103399653A (en) * 2013-07-19 2013-11-20 深圳超多维光电子有限公司 Telescopic device, operating bar and measurement method
US20190131969A1 (en) * 2016-04-22 2019-05-02 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. Elastomer-based Capacitive Control and Operating Element
CN107562237A (en) * 2016-07-01 2018-01-09 南昌欧菲生物识别技术有限公司 Pressure sensitive touch screen
CN107562247A (en) * 2016-07-01 2018-01-09 南昌欧菲光科技有限公司 Touch screen and electronic equipment
CN106708345A (en) * 2017-01-09 2017-05-24 维沃移动通信有限公司 Touch control device and terminal thereof
CN106896970A (en) * 2017-03-15 2017-06-27 上海大学 A kind of touch sensing and preparation method
CN110806223A (en) * 2020-01-08 2020-02-18 腾讯科技（深圳）有限公司 Flexible sensing system, proximity sensing method and device, intelligent robot and equipment
CN112362199A (en) * 2020-10-30 2021-02-12 华中科技大学 Medium insertion type capacitive pressure sensor and preparation method thereof
CN113551811A (en) * 2021-08-16 2021-10-26 吉林大学 Design method of 4D printed multifunctional touch sensor
CN219829751U (en) * 2023-05-29 2023-10-13 浙江舜为科技有限公司 Micro distance detection device and near-to-eye display device

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
APICHART KAEWCHAROEN，ET AL.: "Interdigitated Capacitive Touch Sensor Integrated in Laminated Glass with a Large Sensing Area", 2021 RESEARCH, INVENTION, AND INNOVATION CONGRESS: INNOVATION ELECTRICALS AND ELECTRONICS (RI2C), 31 December 2021 (2021-12-31), pages 102 - 105 *
刘非: "电容式柔性触觉传感器结构设计与特性研究", 中国优秀硕士论文电子期刊网, 15 June 2021 (2021-06-15), pages 140 - 492 *

Similar Documents

Publication Publication Date Title
JP6562357B2 (en) Pressure sensor
CN107290082B (en) Capacitive touch sensor
US20120019479A1 (en) Touch pad for multiple sensing
US7353713B2 (en) Flexible apparatus and method to enhance capacitive force sensing
US20140174204A1 (en) Capacitive shear force sensor and method for fabricating thereof
JP2000181612A (en) Coordinate input device
CN117539366A (en) Capacitive detection structure and electronic equipment
US10901022B2 (en) Electrostatic detecting device
KR20200009206A (en) Force Touch Device
CN117572987A (en) Capacitive detection structure and electronic equipment
US20230064769A1 (en) Pressure sensor
US7921728B2 (en) Flexible apparatus and method to enhance capacitive force sensing
CN118089990A (en) Capacitive detection structure and electronic equipment
JPH085482A (en) Electrostatic capacity type tactile sensor
EP0335693A2 (en) Capacitative weight sensor
CN115201574A (en) Resistance detection and sensor preparation method and device, electronic equipment and storage medium
CN111090331A (en) Pressure sensor and electronic device
CN211696232U (en) Film thickness detection device
CN106775042B (en) Electronic equipment with pressure detection function
CN219842700U (en) Mobile terminal
CN217546020U (en) Key and electronic equipment
JP2023084199A (en) Electronic instrument
CN109975622B (en) Electrostatic detecting device
US11756328B2 (en) Biological information identification apparatus and electronic device
JP2022055908A (en) Sensor unit

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