CN105094449B

CN105094449B - A kind of pressure-sensing input module

Info

Publication number: CN105094449B
Application number: CN201510555223.9A
Authority: CN
Inventors: 李裕文; 蒋承忠; 陈风
Original assignee: TPK Touch Solutions Xiamen Inc
Current assignee: TPK Touch Solutions Xiamen Inc
Priority date: 2015-09-01
Filing date: 2015-09-01
Publication date: 2018-09-28
Anticipated expiration: 2035-09-01
Also published as: CN105094449A

Abstract

The present invention provides a kind of pressure-sensing input module, it includes the first pressure sensitivity unit and the second pressure sensitivity unit that lower surface on the substrate is arranged, the first pressure sensitivity unit is arranged in a one-to-one correspondence with the second pressure sensitivity unit and material identical, at least one first pressure sensitivity unit and the second pressure sensitivity unit of corresponding setting, Wheatstone bridge is constituted with two reference resistances of peripheral hardware, by adjusting the Young's modulus and thickness of substrate and laminating layer, and it is equipped with the adjustment of the pattern form and its arrangement mode of the first pressure sensitivity unit and the second pressure sensitivity unit, to obtain to temperature-insensitive and have the pressure-sensing input module of elevated pressures sensing sensitivity.

Description

Pressure sensing input module

[ technical field ] A method for producing a semiconductor device

The present invention relates to the field of pressure sensing, and more particularly, to a pressure sensing input module.

[ background of the invention ]

With the recent continuous update of touch input technology, a planar touch panel has become the first choice of input devices. Recently, a pressure sensing device with brand-new touch experience has caused a stream of heat tide in the touch input device field, and this kind of pressure sensing device can be through the resistance variation size of the pressure sensing unit after listening to pressing, and judge the size of the pressure degree of pressing, and it can be applied to the touch input device field that only needs the pressure size of listening alone, can also combine with traditional plane touch panel and compromise the detection of two-dimensional coordinate and three-dimensional pressure degree of pressing.

However, due to the limitation of the pressure sensing electrode material, the existing material is inevitably affected by the temperature of the finger, and a certain resistance value is changed, and the resistance value change caused by the temperature change greatly affects the detection of the magnitude of the pressing force, and even the resistance value change caused by the temperature is far larger than the resistance value change amount caused by the magnitude of the pressing force, so that the change detection of the pressure resistance value is inaccurate or even impossible to detect.

[ summary of the invention ]

The invention provides a pressure sensing input module with a temperature compensation function.

In order to solve the technical problems, the invention provides the technical scheme that: a pressure sensing input module is bonded with each module through a bonding layer and comprises a substrate, a first pressure sensing layer and a second pressure sensing layer, wherein the first pressure sensing layer and the second pressure sensing layer are respectively arranged on the upper surface and the lower surface of the substrate; the laminating layer is arranged among the first pressure-sensitive layer, the second pressure-sensitive layer and other modules, the thickness of the laminating layer is 25-125 mu m, and the thickness of the substrate is 50-450 mu m.

Preferably, the pressure sensing input module further includes a first reference resistor and a second reference resistor, and the first pressure sensing unit and the second pressure sensing unit arranged correspondingly form a wheatstone bridge.

Preferably, the wheatstone bridge is configured such that the first pressure sensing unit is connected in series with the first reference resistor, and the second pressure sensing unit provided correspondingly is connected in series with the second reference resistor.

Preferably, the wheatstone bridge is configured such that the first pressure sensing unit is connected in series with the second pressure sensing unit disposed correspondingly, and the first reference resistor is connected in series with the second reference resistor.

Preferably, the first pressure sensing unit array is disposed on the upper surface of the substrate, and the second pressure sensing unit and the first pressure sensing unit are disposed on the lower surface of the substrate correspondingly, so that the pressure sensing input module can simultaneously detect three-dimensional signals.

Preferably, the first pressure sensing unit and the second pressure sensing unit are formed by bending a piezoresistive material in the form of a conducting wire.

Preferably, the shapes of the first pressure sensing unit and the second pressure sensing unit are non-rotational symmetry figures.

Preferably, the pattern of the first pressure sensing unit and/or the second pressure sensing unit is designed such that a total length of the conductive lines in a direction is the largest, the direction is an a direction of the first pressure sensing unit and/or the second pressure sensing unit, and the total length of the conductive lines in the direction is the smallest, the direction is a b direction, wherein the a direction is perpendicular to the b direction.

Preferably, the pattern shape of the first pressure sensing unit and the second pressure sensing unit includes one or a combination of an elliptical winding line shape, a broken line shape, a curved line shape, a long-length multi-segment serial line shape, a non-long-length multi-segment serial line shape or a zigzag line shape.

Preferably, the first pressure sensing unit and the correspondingly arranged second pressure sensing unit are different in shape.

Compared with the prior art, the pressure sensing input module or the pressure sensing input device provided by the invention at least has the following advantages:

1. the invention provides a pressure sensing input module with a temperature compensation function, which comprises a first pressure sensing unit and a second pressure sensing unit which are arranged on the upper surface and the lower surface of a substrate, wherein the first pressure sensing unit and the second pressure sensing unit are correspondingly arranged and are made of the same material, and at least one first pressure sensing unit and the second pressure sensing unit which are correspondingly arranged form a Wheatstone bridge together with two externally-arranged reference resistors (a resistor Ra and a resistor Rb).

The Wheatstone bridge is adopted to detect the pressing force value, and the circuit structure is simple and the control precision is high. Since the materials of the first pressure sensing unit and the second pressure sensing unit are the same, the change of the resistance values of the first pressure sensing unit and the second pressure sensing unit caused by the temperature change satisfies (RF0+ Δ RF0)/(RC0+ Δ RC0) ═ RF0/RC0, and it can be seen that since the first pressure sensing unit and the second pressure sensing unit are made of the same material and jointly form a wheatstone bridge, the influence of the temperature on the resistance values of the first pressure sensing unit and the second pressure sensing unit can be ignored in the process of measuring the resistance values, and therefore the pressure sensing input module provided by the invention can completely compensate the change of the resistance values caused by the temperature.

2. In the pressure sensing input device provided by the invention, the Young modulus and the thickness of the substrate and the laminating layer influence the neutral surface of the pressure sensing input device, and when the neutral surface is positioned in the substrate, the strain difference between the first pressure sensing unit and the second pressure sensing unit arranged on the upper main surface and the lower main surface of the substrate can reach the maximum value. Therefore, on the premise that the young modulus of the substrate is set to be larger than that of the laminating layer by at least one order of magnitude: (1) the Young modulus of the laminating layer is controlled within the range of 0-3000MPa, so that the strain difference delta epsilon can be increased; (2) when the thickness of the laminating layer is limited within the range of 25-125 mu m, the strain difference delta epsilon tends to increase along with the reduction of the thickness of the laminating layer; (3) when the thickness of the substrate is limited to the range of 50 to 450 μm, the strain difference Δ ∈ tends to increase as the thickness of the substrate increases. Therefore, the young modulus and the thickness of the substrate and the laminating layer of the pressure sensing input device are adjusted, so that the strain difference of the pressure sensing units on the upper surface and the lower surface of the substrate can be increased, the pressure detection is more accurate, and the pressing force detection is more sensitive.

3. In the pressure sensing input module provided by the invention, the first pressure sensing unit and the second pressure sensing unit are designed into a pattern with a long axis direction and a short axis direction, and the total line length of the long axis direction is larger than that of the short axis direction. In the present invention, the pattern shape of the first pressure-sensitive cells and the second pressure-sensitive cells may further include one or a combination of a shape such as an elliptical winding shape, a zigzag shape, a curved shape, a long-length multi-stage serial line shape, a short-length multi-stage serial line shape, and a zigzag line shape. When the first pressure sensing unit or the second pressure sensing unit is deformed due to finger pressing (point pressing), the first pressure sensing unit or the second pressure sensing unit has different strain in the a direction and the b direction due to the fact that the total length in the a direction is different from the total length in the b direction, and therefore the resistance value change effect can be effectively increased, and the response of the first pressure sensing layer or the second pressure sensing layer to pressure is more accurate and sensitive.

4. In the pressure sensing input module provided by the invention, in order to achieve that the difference value between the strain of the first pressure sensing unit and the strain of the second pressure sensing unit can reach a larger value, so that the pressure detection sensitivity of the pressure sensing input module is improved. Wherein the angle a1 and the angle a2 range from 0 to 45 degrees when the strains of the first pressure sensing unit and the second pressure sensing unit are positive and negative, the angle a1 ranges from 0 to 45 degrees and the angle a2 ranges from 45 to 90 degrees when the strains are simultaneously negative, or the angle a1 ranges from 45 to 90 degrees and the angle a2 ranges from 0 to 45 degrees when the strains are simultaneously positive. In addition, in order to make the strain difference Δ ∈ between the first pressure-sensitive cells and the second pressure-sensitive cells large, the relationship between the pattern shapes of the first pressure-sensitive cells and the second pressure-sensitive cells may be defined. The limitation of the above conditions can maximize the strain change values of the first pressure sensing unit and the second pressure sensing unit. After the first pressure sensing unit receives the pressing acting force, the strain amount in the direction a is greater than the strain amount in the direction b, so that the strain generated by the pressing force applied to the first pressure sensing unit and the second pressure sensing unit can be reflected in a concentrated manner in one direction, and when the concentrated direction of the strain is consistent with the maximum strain direction generated by the pressing acting force in the area, the strain difference delta epsilon of the first pressure sensing unit and the second pressure sensing unit can be made to be more specific, so that the magnitude of the pressing force can be reflected more accurately, and the sensitivity of pressure detection can be improved.

5. The pressure sensing input module adopts resistance type pressure sensing, and the corresponding resistance value is changed due to the change of the shape in the pressure sensing unit, so that the position of a pressing point and the size of pressing force are judged according to the position and the size of variation generated by the resistance value change, and the position detection (planar two-dimensional) and the calculation of the force detection (third dimension) are carried out by using the same pressure sensing unit, so that the simultaneous detection of three dimensions is realized.

[ description of the drawings ]

FIG. 1A is a schematic diagram of a layered structure of a pressure-sensing input module according to a first embodiment of the present invention.

FIG. 1B is a schematic diagram of the pressure signal detection of FIG. 1A.

FIG. 1C is another schematic diagram of the pressure signal detection of FIG. 1A.

Fig. 2A is a schematic diagram of a layered structure of a pressure-sensing input module according to a second embodiment of the present invention.

Fig. 2B is a schematic structural view of the pressure sensing input module shown in fig. 2A deformed by a pressing force.

Fig. 2C is a graph showing strain amounts of respective layers after the pressure sensing input module shown in fig. 2B receives a pressing force.

Fig. 3A is a schematic diagram illustrating a relationship between a strain difference between the first pressure-sensing unit and the second pressure-sensing unit and a young's modulus of the adhesive layer according to the second embodiment of the invention.

Fig. 3B is a schematic diagram illustrating another relationship between the strain difference between the first pressure-sensing unit and the second pressure-sensing unit and the young's modulus of the adhesive layer according to the second embodiment of the invention.

Fig. 3C is a schematic diagram illustrating a relationship between a strain difference between the first pressure-sensing unit and the second pressure-sensing unit and a thickness of the adhesive layer according to the second embodiment of the disclosure.

Fig. 3D is a schematic diagram illustrating a relationship between a strain difference between the first pressure sensing unit and the second pressure sensing unit and a thickness of the substrate according to the second embodiment of the present invention.

Fig. 4 is a schematic plan view of a first pressure-sensing layer of a pressure-sensing input module according to a fourth embodiment of the invention.

Fig. 5A is a schematic plan view of a first pressure-sensing layer and a pressing region thereof of a pressure-sensing input module according to a fourth embodiment of the invention.

Fig. 5B-5E are schematic strain diagrams of the compression zones at a-D in fig. 5A.

Fig. 6A is a schematic plan view of a single first pressure-sensitive cell of fig. 4.

Fig. 6B is a schematic view of the lengths of the first pressure-sensitive cells in the a and B directions and the long axis direction in fig. 6A.

Fig. 6C-6G are schematic structural views of modified embodiments of a single first pressure-sensing unit in fig. 4.

Fig. 7A is a schematic cross-sectional view illustrating a first pressure-sensing layer, a substrate, and a second pressure-sensing layer of a pressure-sensing input module according to a fifth embodiment of the invention.

Fig. 7B is a strain-thickness relationship for the structure shown in fig. 7A.

Fig. 8A is a schematic view of a long axis direction of the first pressure sensing unit of the pressure sensing input module shown in fig. 6A.

Fig. 8B is a schematic longitudinal direction view of a second pressure-sensitive cell provided in correspondence with the first pressure-sensitive cell shown in fig. 8A.

[ detailed description ] embodiments

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1A, a pressure sensing input module 10 according to a first embodiment of the present invention includes a substrate 11, and a first pressure sensing layer 12 and a second pressure sensing layer 13 respectively disposed on upper and lower surfaces of the substrate 11 (in the present invention, the upper and lower position words are only used for defining relative positions in a designated view). The first pressure-sensitive layer 12 is provided with at least one first pressure-sensitive unit 121, the second pressure-sensitive layer 13 is provided with at least one second pressure-sensitive unit 131, and the at least one first pressure-sensitive unit 121 and the at least one second pressure-sensitive unit 131 are arranged in a one-to-one correspondence manner, wherein the one-to-one correspondence in the invention means that the number and distribution positions of the first pressure-sensitive units 121 and the second pressure-sensitive units 131 on the upper surface and the lower surface of the substrate 11 are in one-to-one correspondence, and the pattern shapes of the first pressure-sensitive units 121 and the second pressure-sensitive units 131 are not limited. When the substrate 11 is pressed, the at least one first pressure sensing unit 121 and the at least one second pressure sensing unit 131 corresponding to the pressing point will be pressed.

The first pressure sensing unit 121 and the second pressure sensing unit 131 are deformed, deflected or sheared due to pressing, and thus at least one electrical property is changed, and particularly, when the first pressure sensing unit 121 and the second pressure sensing unit 131 are formed by bending a piezoresistive material in a form of a wire, the lengths of the wires of the first pressure sensing unit 121 and the second pressure sensing unit 131 in corresponding regions are changed after pressing, and thus resistance values of the first pressure sensing unit 121 and the second pressure sensing unit 131 are affected.

The materials of the first pressure sensing unit 121 and the second pressure sensing unit 131 include metals such as silver, copper, Aluminum, gold, and alloys thereof, or similar metal oxides such as Indium Tin Oxide (ITO), Antimony Tin Oxide (ATO), Indium Zinc Oxide (IZO), and Aluminum Zinc Oxide (AZO), or one or more of graphene, metal mesh, nano silver wire, and carbon nanotube.

Substrate 11 may include, but is not limited to: rigid substrates such as glass, tempered glass, sapphire glass, and the like; the substrate may be a flexible substrate, such as PEEK (polyetheretherketone), PI (Polyimide), PET (polyethylene terephthalate), PC (polycarbonate), PES (polyethylene glycol succinate), PMMA (polymethyl methacrylate), PVC (Polyvinyl chloride), PP (Polypropylene), and a composite of any two thereof.

The internal resistances corresponding to the first pressure-sensing units 121 in the pressure-sensing input module 10 provided by the first embodiment of the present invention are RF0, RF1, RF2 · · RFn, and when receiving a pressing force, the resistances of the internal resistances corresponding to the first pressure-sensing units 121, RF0, RF1, RF2 · · RFn change; the internal resistances of the second pressure sensing units 131 in the pressure sensing input module 10 are RC0, RC1, and RC2 · · RCn, which are respectively disposed on two sides of the substrate 11 corresponding to RF0, RF1, and RF2 · · RFn, respectively, and when receiving the pressing force, the resistances of the internal resistances RC0, RC1, and RC2 · · RCn corresponding to the second pressure sensing units 131 also change. The first pressure sensing units 121 and the second pressure sensing units 131 are disposed in a one-to-one correspondence manner on the number and distribution positions of the upper and lower surfaces of the substrate 11, and the pattern shapes of the first pressure sensing units 121 and the second pressure sensing units 131 are not limited.

In the present invention, two ends of the conductive wire of the first pressure sensing unit 121 are electrically connected to a signal processing center (not shown), and two ends of the conductive wire of the second pressure sensing unit 131 are electrically connected to the same signal processing center (not shown), respectively, and the signal processing center further includes a first reference resistor Ra, a second reference resistor Rb and a multiplexer. Through the control of the multiplexer, the first pressure sensing unit 121 resistors RFn (where n is 0,1,2 … n) and the second pressure sensing unit resistors 131RCn (where n is 0,1,2 … n) disposed corresponding thereto form a wheatstone bridge with the resistors Ra and Rb in sequence.

As shown in fig. 1B and 1C, the resistor RFn, the resistor RCn, the first reference resistor Ra, and the second reference resistor Rb may be connected in two ways. As shown in fig. 1B, one end of the resistor RFn is electrically connected to a positive power terminal VEX +, and the other end is connected in series with the first reference resistor Ra; one end of the resistor RCn is electrically connected to the same power supply positive terminal VEX +, and the other end is connected in series with the second reference resistor Rb; the other ends of the first reference resistor Ra and the second reference resistor Rb are electrically connected to the negative terminal VEX of the power supply (or to ground), and a voltmeter is used for measuring the potential difference signal U0 of the resistor RFn and the resistor RCn. Or as shown in fig. 1C, one end of the resistor RFn is electrically connected to a positive terminal VEX + of a power supply, and the other end is connected in series with the resistor RCn; one end of the first reference resistor Ra is electrically connected to the same power supply positive terminal VEX +, and the other end of the first reference resistor Ra is connected with the second reference resistor Rb in series; the other ends of the resistor RCn and the second reference resistor Rb are electrically connected to the negative terminal VEX of the power supply (or to ground) and a voltmeter is used for measuring the potential difference signal U0 of the resistor RFn and the first reference resistor Ra.

When no pressing force is applied, each Wheatstone bridge is in a balanced state. When the pressure force acts on the pressure sensor, the resistance values of one or more first pressure sensing units 121 and the correspondingly arranged second pressure sensing units 131 at the corresponding positions are changed, the balance of the Wheatstone bridge is broken, so that the output potential difference signal U0 is changed without fail, different pressure values correspond to the change of the resistance values, and correspondingly different potential difference signals are generated, so that the corresponding pressure value can be obtained by calculating and processing the potential difference signal U0 of the Wheatstone bridge.

As shown in FIG. 1B, the resistor RF0, the resistor RC0, the resistor Ra and the resistor Rb form a Wheatstone bridge, and the relationship can be expressed as:

as shown in fig. 1C, the resistor RF0, the resistor RC0, the resistor Ra, and the resistor Rb form a wheatstone bridge, and the relationship can be expressed as:

in the pressure sensing input module according to the first embodiment of the present invention, the relationship between the resistance and the temperature change can be derived by the following formula: the formula for the resistance R of an object is:

R＝ρL/S (1)；

where ρ represents the resistivity of the material constituting the first pressure sensing unit 121 and the second pressure sensing unit 131, L represents the length of the first pressure sensing unit 121 and the second pressure sensing unit 131 in the present invention, and S represents the cross-sectional area of the first pressure sensing unit 121 and the second pressure sensing unit 131 in the current direction.

The formula of the change of the resistivity rho of the materials composing the first pressure sensing unit 121 and the second pressure sensing unit 131 along with the temperature is as follows:

ρ_T＝ρ(1+αT) (2)；

where ρ is the resistivity of the material constituting the first pressure sensing unit 121 and the second pressure sensing unit 131, α is the temperature coefficient of resistance, and T is the temperature.

Combining formula (1) above with formula (2):

when the ambient temperature is T₀When (e.g., T is 0), the resistance value of the object is:

R_T0＝ρL/S (3)；

when the ambient temperature is T₁The resistance value of the object is:

R_T1＝ρL/S(1+α(T₁-T₀)) (4)；

from the above-mentioned formulas (1) to (4), Δ R of the resistance value of the material affected by temperature can be derived_TCan be represented by the following formula (5):

ΔR_T＝R_T1-R_T0

＝ρL/S(1+α(T₁-T₀))-ρL/S

＝αΔT(ρL/S)

＝ΔTα·R (5)；

where Δ T represents a temperature change amount.

In the pressure sensing input module 10 according to the first embodiment of the present invention, the relationship among RF0, RC0, Ra, and Rb in the wheatstone bridge is expressed as the above expression (Q) and expression (P).

Taking equation (Q) as an example, when the temperature changes (the temperature change amount is represented by Δ T), the resistance change amounts of the second pressure sensing units 131, which are disposed corresponding to the first pressure sensing units 121 and the positions thereof, are respectively expressed by equations (6) and (7):

ΔRF0＝ΔTα×RF0 (6)；

ΔRC0＝ΔTα×RC0 (7)；

from the above equations (1) to (8), it can be found that the resistance change of the second pressure-sensitive cells 131 provided in the first pressure-sensitive cell 121 and the positions thereof is expressed by the equation (8):

(8)；

as can be seen from equation (9), the first pressure-sensitive cells 121 and the second pressure-sensitive cells 131 are made of the same material, and equation (8) can further obtain equation (9) at the same amount of temperature change:

as can be seen from the above equation (9), when the same material is used for the first pressure sensing unit 121 and the second pressure sensing unit 131, the temperature coefficient α is the same under the same temperature variation Δ T according to the temperature conduction characteristic, and the temperature variations Δ RF0 and Δ RC0 of the resistance values of the first pressure sensing unit 121 and the second pressure sensing unit 131 can be cancelled by each other in the resistance value measurement process by the manner shown in equation (9), so that the temperature influence on the pressure sensing input module 10 is zero.

Taking formula (P) as an example, it is different from formula (Q) in that the temperature variation is Δ T:

the specific derivation process of equation (10) is the same as equations (8) and (9), and therefore, the description thereof is omitted here.

As is clear from the results of the above equations (9) and (10), the wheatstone bridge configuration shown in fig. 1B and 1C achieves complete temperature compensation by making the temperature influence zero on the resistance values of the first pressure-sensitive cells 121 and the second pressure-sensitive cells 131 provided corresponding thereto.

In addition, according to the characteristics of force transmission, since the first pressure sensing unit 121 and the second pressure sensing unit 131 are separately disposed on the upper and lower surfaces of the substrate 11, and the substrate 11 has a certain thickness, the upper and lower layers of the substrate 11 may have different deformations after receiving a pressing force, and further, the first pressure sensing unit 121 and the second pressure sensing unit 131 disposed on the upper and lower surfaces may also have different deformations. Further, the difference in the deformation of the upper and lower layers of the substrate 11 and the first pressure-sensitive cells 121 and the second pressure-sensitive cells 131 is different depending on the pressing force.

The wheatstone bridges shown in fig. 1B and 1C are in equilibrium when no compressive force is acting. When acted upon by a pressing force, one or more resistances of the first pressure sensing element 121 and/or the second pressure sensing element 131 change, such that the wheatstone bridge balance is broken and the output electrical signal U0 must change: if the contact pressure force is large, the resistance values of the first pressure sensing unit 121 and the second pressure sensing unit 131 have large variation; on the contrary, if the force of the touch pressure is small, the resistance values of the first pressure sensing unit 121 and the second pressure sensing unit 131 have a small variation amount. The changes of different resistance values correspond to different pressure values, so that the corresponding pressure values can be obtained by calculating and processing the output signal U0 of the Wheatstone bridge.

In the present invention, when the first pressure units 121 and the second pressure units 131 are arranged on the upper and lower surfaces of the substrate 11 in an array, the pressure sensing input module may not only detect the magnitude of the pressing force, but also detect the three-dimensional signals of the pressing position (planar two-dimensional) and the pressing force (third-dimensional) synchronously. After pressing, the shape change inside the first pressure sensing unit 121 and the second pressure sensing unit 131 causes corresponding resistance value change, the position of the pressed point and the size of the pressing force can be judged according to the position and the variation generated by calculating the resistance value change, and the first pressure sensing unit 121 and the second pressure sensing unit 131 which are correspondingly arranged up and down are used for both position detection (planar two-dimensional) and force detection (third dimension) calculation, so that three-dimensional simultaneous detection is realized.

In order to form a pressure-sensing input device for touch input, it is necessary to add other modules on the basis of the pressure-sensing input module 10 provided in the first embodiment of the present invention. In addition, due to the pressing force and the deformation characteristics thereof, when the pressure sensing input module 10 is stacked with other modules, the thickness, young modulus, and other parameters of the adhesive layer for adhering each module to the pressure sensing input module 10 will affect the sensing sensitivity and accuracy of the pressure sensing input module 10 to the magnitude of the pressure value.

Referring to fig. 2A-2B, a pressure-sensing input device 20 according to a second embodiment of the present invention includes a cover 24, a first adhesion layer 221, a pressure-sensing input module 21, a second adhesion layer 222, and a supporting layer 25. The pressure sensing input module 21 is similar to the pressure sensing input module provided in the first embodiment, and includes a substrate 201, and a first pressure sensing layer 202 and a second pressure sensing layer 203 disposed on the upper and lower surfaces of the substrate 201, where the first pressure sensing layer 202 includes at least one first pressure sensing unit 211, and the second pressure sensing layer 203 includes at least one second pressure sensing unit 212, and the specific structures of the first pressure sensing unit 211 and the second pressure sensing unit 212 are the same as those of the first embodiment of the present invention, and are not repeated herein.

The cover plate 24 may be made of a hard cover plate, such as glass, tempered glass, sapphire glass, etc.; the cover plate may be a soft cover plate, such as PEEK (polyetheretherketone), PI (Polyimide), PET (polyethylene terephthalate), PC (polycarbonate), PES (polyethylene succinate, PMMA (polymethyl methacrylate), and a composite of any two thereof.

The first Adhesive layer 221 and the second Adhesive layer 222 may be Optical Clear Adhesive (OCA) or Liquid Optical Clear Adhesive (LOCA).

In further embodiments, the support layer 25 may further be a display layer, which may include Liquid Crystal Display (LCD) elements, Organic Light Emitting Diode (OLED) elements, electroluminescent displays (ELDs), and the like.

Referring to fig. 2B, when the cover plate 24 is pressed by a finger, the force generated by the finger pressing is transmitted to the supporting layer 25 from top to bottom layer by layer. During finger pressure, strain is related to the thickness, material, of the layers that make up the pressure sensing input device 20. In one embodiment of the present invention, the thickness of the pressure-sensing input device 20 is about 950 μm, after the finger presses the pressure-sensing input device 20, the upper surface of the pressure-sensing input device 20 is represented as a zero point of the thickness, the Strain of the pressure-sensing input device 20 is measured from top to bottom, the thickness of the pressure-sensing input device 20 and the corresponding Strain amount are compared, and a Strain (Elastic Strain) -thickness relation graph as shown in fig. 2C is obtained by plotting.

In the present embodiment, the pressure-sensing input device 20 includes the cover plate 24, the first adhesion layer 221, the pressure-sensing input module 21, the second adhesion layer 222 and the support layer 25, and the variation of the parameters such as the thickness and the young's modulus of any one of the above layers will affect the form of the curve in the variable-thickness relationship diagram, so the strain-thickness relationship diagram shown in fig. 2C only represents the approximate trend diagram of the similar structure under specific conditions.

The pressure sensing input device 20 includes at least one neutral plane (not shown), which is a plane where an object deforms to zero under a force, and the strain in the neutral plane becomes zero, i.e. the strain value is zero. As shown at Z in fig. 2C, the strain values of the corresponding layer thicknesses of the pressure-sensing input device 20 pointed at Z are all zero, and five neutral surfaces of the pressure-sensing input device 20 corresponding to Z are respectively located in the cover plate 24, the first adhesive layer 221, the pressure-sensing input module 21, the second adhesive layer 222, and the supporting layer 25. The strain value of the pressure sensing input device 20 is divided into positive strain and negative strain (the positive strain and the negative strain in this case and below indicate that the deformation states are tensile and compressive), with a neutral surface as an interface.

As can be seen from fig. 2B and 2C, when a finger presses, the strain of the upper surface of the corresponding pressure-sensing input device 20 (the upper surface of the cover plate 24) is 1.7225 e-5;

within the cover plate 24, the strain gradually increases and changes from negative strain-zero strain-positive strain;

the strain value corresponding to the position I is the strain value of the joint surface of the cover plate 24 and the first bonding layer 221, and the strain of the joint surface reaches the highest value 1.6478 e-5;

in the first lamination layer 221, the strain gradually decreases, and the variation trend is positive strain-zero strain-negative strain;

the strain value corresponding to the position ii is a strain value of a joint surface of the first adhesive layer 221 and the pressure sensing input module 21, and the strain of the joint surface is a negative direction strain and is close to zero;

in the pressure sensing input module 21, the strain gradually increases, and after reaching a certain value (about 5e-5), the strain does not increase along with the increase of the thickness;

the strain value corresponding to the position iii is a strain value of a joint surface of the pressure sensing input module 21 and the second adhesive layer 23, and the corresponding strain of the joint surface is about 5 e-5;

in the second lamination layer 222, the strain gradually decreases, and the trend of the change is positive strain-zero strain-negative strain;

the strain value corresponding to position iv is the strain value of the bonding surface of the second bonding layer 222 and the supporting layer 25, and the corresponding strain of the bonding surface is about-9.7 e-6;

within the support layer 25, the strain gradually rises with a trend of negative strain-zero strain-positive strain.

It can be seen that, in the pressure-sensing input device 20, at the joints between the first adhesive layer 22 and the cover plate 24 and the pressure-sensing input module 21, and at the joints between the second adhesive layer 23 and the pressure-sensing input module 21 and the supporting layer 25, the trend of the change of the strain is changed, so that the strain changes from positive to negative or from negative to positive, and it can be seen that the arrangement of the first adhesive layer 22 and the second adhesive layer 23 reduces the strain of the pressure-sensing input device 20, and since the first adhesive layer 22 and the second adhesive layer 23 are joined to the pressure-sensing input module 21, the influence of the first adhesive layer 22 and the second adhesive layer 23 on the reduction of the strain of the pressure-sensing input module 21 is smaller, and the strain value of the pressure-sensing input module 21 is larger.

The larger the strain difference between the first pressure sensing units 211 and the second pressure sensing units 212 which are arranged on the upper surface and the lower surface of the substrate 201 in a one-to-one correspondence manner before and after being subjected to the pressing force is, the larger the corresponding resistance value difference is, and thus the pressure sensing input device 20 with high sensitivity to the pressing force is obtained.

In practical applications, in the five-layer structure of the pressure sensing input device 20, the first adhesive layer 221, the second adhesive layer 222 are bonded to the first pressure sensing unit 211 and the second pressure sensing unit layer 212, the first pressure sensing unit 211 and the second pressure sensing unit layer 212 are disposed on the upper and lower surfaces of the substrate 201, and the material selectivity of the first adhesive layer 221, the second adhesive layer 222 and the substrate 201 is the most.

Referring to fig. 3A, in a first modification of the pressure-sensing input device 20 according to the second embodiment of the present invention, the young's modulus E of the substrate 201₁The thickness of the substrate 201 is preferably 100 μm at 73.3 GPa. The thickness of the lamination layer 22 (including the first lamination layer 221 and/or the second lamination layer 222) is 50 μm, and the young's modulus E of the lamination layer 22₂In the range of 100 to 3000MPa, the Young's modulus E of the substrate 201₁Young's modulus E of the adhesive layer₂Greater by at least one order of magnitude or more, i.e. E₁/E₂>10; in the present modified embodiment:

E₁/E₂>＝24.4；

the young's modulus of the adhesive layer 22 is very small compared to the young's modulus of the substrate 201, and thus, the difference in characteristics between the adhesive layer 22 and the substrate 201 is large, and the magnitudes of the strains of the first pressure-sensitive cells 211 and the second pressure-sensitive cells 212 provided on the substrate 201 are likely to reflect the change in the substrate 201, and the strains tend to increase, so that a larger strain difference Δ ∈ can be obtained. The strain difference Δ ∈ between the first pressure-sensitive cells 211 and the second pressure-sensitive cells 212 increases as the young's modulus of the adhesive layer 22 decreases, wherein when the young's modulus of the adhesive layer 22 is 100 to 1000MPa, the strain difference Δ ∈ significantly increases as the young's modulus of the adhesive layer 22 decreases.

After many studies, the following conclusions can be drawn: when the young's modulus of the substrate 22 is a fixed value and is at least one order of magnitude greater than the young's modulus of the adhesive layer 22, the strain difference Δ ∈ is inversely related to the young's modulus of the adhesive layer 22.

In further embodiments, E₁/E₂More preferably greater than or equal to 100.

Referring to fig. 3B, a second modification of the pressure-sensing input device 20 according to the second embodiment of the present invention is different from the first modification in that the young's modulus of the substrate 201 is only 6000MPa, and when the young's modulus of the adhesive layer 22 is 1000-3000MPa, the young's modulus E of the substrate 201 is₁Young's modulus E of adhesive layer 22₂In a ratio of 2 to 6, E₁/E₂The value is less than 10. The magnitude of the strain of the first pressure sensing unit 211 and the second pressure sensing unit 212 disposed on the substrate 201 is related to both the adhesive layer 22 and the substrate 201, and since the difference between the young's modulus of the adhesive layer 22 and the young's modulus of the substrate 201 is small, when the adhesive layer 22 and the substrate 201 have similar performance (e.g., elastic performance), the strain difference between the first pressure sensing unit 211 and the second pressure sensing unit 212 changes irregularly, which means that when the young's modulus E of the substrate 201 is equal to the young's modulus E₁Is smaller value and has Young's modulus E with laminating layer 22₂When the ratio of (d) is less than 10, the effect of young's modulus of adhesive layer 22 on increasing strain difference Δ ∈ is insignificant.

Referring to fig. 3C, a third modification of the pressure-sensing input device 20 according to the second embodiment of the present invention is different from the first modification in that when the thickness of the adhesive layer 22 is in a range of 25-125 μm, the strain difference Δ ∈ between the first pressure-sensing unit 211 and the second pressure-sensing unit 212 is inversely proportional to the variation of the thickness of the adhesive layer 22. Since the adhesive layer 22 reduces the strain value of the first pressure-sensitive cells 211 and the second pressure-sensitive cell layers 212 provided in correspondence with the first pressure-sensitive cells 211, the effect of the adhesive layer 22 on the first pressure-sensitive cells 211 and the second pressure-sensitive cells 212 is reduced as it becomes thinner, and the strain difference Δ ∈ can be made larger, but the effect of the change in thickness of the adhesive layer 22 on the strain difference Δ ∈ is much smaller than the effect of the young's modulus of the adhesive layer 22 on the strain difference Δ ∈. When the thickness range of the adhesive layer 22 is smaller than 25 μm, the adhesive layer 22 cannot be bonded due to too thin thickness, so that the bonding between the structures in the pressure-sensing input device 20 is not tight, and the product quality of the pressure-sensing input device 20 is reduced; when the thickness range of the adhesive layer 22 is larger than 125 μm, the thickness of the adhesive layer 22 is too large, so that when the pressure sensing input device 20 is pressed, the strain values of the first pressure sensing unit 211 and the second pressure sensing unit layer 212 correspondingly disposed thereon are both small, and the difference therebetween (i.e., the strain difference Δ ∈) is also correspondingly small.

Referring to fig. 3D, a fourth modification of the pressure-sensing input device 20 according to the second embodiment of the present invention is different from the first modification in that when the thickness of the substrate 201 is in a range of 50-450 μm, the strain difference Δ ∈ between the first pressure-sensing unit 211 and the second pressure-sensing unit 212 is proportional to the change of the thickness of the substrate 201. Since the strain difference Δ ∈ between the first pressure sensitive cells 211 and the second pressure sensitive cells 212 provided on the upper and lower surfaces of the substrate 201 is positively correlated with the strain value of the substrate 201 as the thickness of the substrate 201 increases, the strain difference Δ ∈ increases as the strain of the substrate 201 increases as the thickness increases. However, too thick the substrate 201 affects the temperature compensation effect between the first pressure sensing unit 211 and the second pressure sensing unit 212 on the upper and lower surfaces of the substrate 201 and the overall thickness of the device, and thus, when the thickness of the substrate 201 is in the range of 50 to 450 μm, the strain difference Δ ∈ is positively correlated with the thickness of the substrate 201.

When the thickness of the substrate 201 is less than 50 μm, the strain difference Δ ∈ between the first pressure sensing unit 211 and the second pressure sensing unit 212 disposed on the upper and lower main surfaces of the substrate 201 is small due to the thinness of the pressure sensing input device 20, and the magnitude of the degree of pressing force cannot be sensed effectively; when the thickness of the substrate is greater than 450 μm, not only the overall thickness of the pressure sensing input device 20 is too large, but also the temperature variation between the first pressure sensing unit 211 and the second pressure sensing unit 212 is different, thereby affecting the temperature compensation effect.

A third embodiment of the present invention provides a pressure-sensing input device, which is different from the second embodiment described above in that by adjusting the thickness of each layer structure of the pressure-sensing input device and its young's modulus in this embodiment, so that one of the at least one neutral plane of the overall structure of the pressure sensing input device is located at the mechanically neutral plane of the substrate, wherein the neutral plane is a plane where the strain in the pressure sensing input module is zero, so that the strains of the first pressure sensing unit (not shown) and the second pressure sensing unit (not shown) disposed on the upper and lower main surfaces of the substrate are positive and negative, and therefore, the strain difference Δ ∈ between the first pressure-sensitive cell and the second pressure-sensitive cell is larger than the case where the strains are both positive or both negative by the same pressing force, and the strain difference Δ ∈ between the first pressure-sensitive cell and the second pressure-sensitive cell is advantageously increased.

Furthermore, the best solution is to design the thickness and young's modulus of each layer so that the whole structure has only a neutral plane and is located in the mechanical neutral plane of the substrate. That is, the mechanical symmetry center of the whole structure is located on the mechanical neutral plane of the substrate, so that the strain difference Δ ∈ between the first pressure sensing unit and the second pressure sensing unit can be maximized under the same pressing force. Therefore, the pressure sensing sensitivity of the pressure sensing input module can be effectively improved.

The magnitude of the stress difference between each first pressure sensing unit and the corresponding second pressure sensing unit (not shown) in the pressure sensing input module is related to the position of the neutral surface, the thickness and the young's modulus of the substrate and the adhesive layer, and the pattern shapes and the arrangement modes of the first pressure sensing unit and the second pressure sensing unit.

Referring to fig. 4, a fourth embodiment of the present invention provides a pressure sensing input module 40, which is different from the first embodiment in that the first pressure sensing layer 42 is provided with the first pressure sensing units 421 distributed in an array, and fig. 4 only illustrates the first pressure sensing units 421 in a 5-column × 9-column array, and the actual number thereof is not limited. Because the pressure sensing input module 40 is square (non-circular), it is affected by its shape, so that different areas on the plane of the first pressure sensing layer 42 are not deformed to the same extent in all directions after being pressed by the pressing force, and it has the maximum deformation extent in one direction and the minimum deformation extent in the other direction. Wherein, the size of the deformation degree is related to the pattern shape of the pressure-sensitive unit. In addition, in order to improve the sensitivity of the pressure sensing, it is preferable to design the pattern of the first pressure sensing unit 421 to have the maximum length in the direction of the maximum deformation degree (the maximum strain direction).

Specifically, referring to fig. 5A, when a finger presses the pressure-sensing input module 40, the first pressure-sensing layer 42 is subjected to a force and deforms to a certain extent. Since the conventional pressure-sensing input module 40 is square, (non-circular, circular has rotation invariance), has no rotation invariance, and is influenced by its shape, the strain levels of each point on the plane of the first pressure-sensing layer 42 in all directions after being pressed by the pressing force are not exactly the same, and it may have the maximum strain in one direction, and the minimum strain in the other direction perpendicular to the one direction, and the strain levels in the other directions are between the two directions. Wherein, the direction of the maximum deformation degree in a certain region is defined as the maximum strain direction of the region, and the direction of the minimum deformation degree in the region is defined as the minimum strain direction of the region, wherein the maximum strain direction and the minimum strain direction are perpendicular to each other.

In the pressure-sensing input module 40 without rotation invariance, the maximum strain directions of different areas on the plane of the first pressure-sensing layer 42 are not necessarily the same, and specific examples are as follows: the stress areas of the pressing are respectively selected to be located at the center (as shown at a in fig. 5A), at the diagonal (as shown at B in fig. 5A), at the middle of the long edge (as shown at C in fig. 5A), and at the middle of the short edge (as shown at D in fig. 5A) of the first pressure-sensitive layer 42.

When the force-receiving area of the pressing is located at the center of the first pressure-sensitive layer 42, the direction of maximum strain at the center is the direction S as shown in fig. 5B_InShown, the direction of maximum strain S_InParallel to the longitudinal direction of the first pressure-sensitive layer 42;

when the force-receiving area for pressing is located at a pair of corners of the first pressure-sensitive layer 42, the maximum strain direction at the pair of corners is the direction S in fig. 5C_CornerShown, the direction of maximum strain S_CornerPerpendicular to the diagonal connected by the diagonal;

when the force-receiving area of the pressing is located at the midpoint of the long side of the first pressure-sensitive layer 42, the direction of maximum strain at that position is the direction S in fig. 5D_{Long and long}Shown, the direction of maximum strain S_{Long and long}Perpendicular to the longitudinal direction of the first pressure-sensitive layer 42;

when the pressed force-receiving area is located at the midpoint of the short side of the first pressure-sensitive layer 42, the direction of maximum strain at this point is the direction S in fig. 5E_{Short length}Shown, the direction of maximum strain S_{Short length}Parallel to the longitudinal direction of the first pressure-sensitive layer 42.

The stress-bearing areas pressed in the fourth embodiment of the present invention are only illustrated by the center, diagonal, middle of the long edge and middle of the short edge shown in fig. 5B-5E, and the stress-bearing areas actually pressed are not limited.

The above description of the maximum strain direction of the first pressure-sensitive layer 42 also applies to the second pressure-sensitive layer (not shown), and the maximum strain directions of the corresponding regions of the first pressure-sensitive layer 42 and the second pressure-sensitive layer are generally the same when the same pressing force is applied according to the specific laminated structure of the pressure-sensing input module 40.

In this embodiment, the shapes of the first pressure sensing unit 421 and the second pressure sensing unit (not shown) are non-rotational symmetrical figures.

Referring to fig. 6A-6B, in a fourth embodiment of the present invention, the first pressure sensing unit 421 is in an elliptical winding shape, wherein a major axis direction of the first pressure sensing unit 421 is an a direction (i.e., a total length La of the first pressure sensing unit 421 along the a direction is maximum), a minor axis direction of the first pressure sensing unit 421 is a B direction (i.e., a total length Lb of the first pressure sensing unit 421 along the B direction is minimum), and in an embodiment, the a direction is perpendicular to the B direction.

The total length of the first pressure sensing unit 421 having the elliptical winding shape is the largest in the a direction and the total length in the b direction is the smallest, and the amount of strain in the a direction is larger than the amount of strain in the b direction when the first pressure sensing unit 421 is pressed, so that the strain generated by the pressing force applied to the first pressure sensing unit 421 can be concentrated in one direction, and the deformation of the first pressure sensing unit 421 is larger. Since the first pressure sensing unit 421 is deformed in a single direction, the resistance RFn of the first pressure sensing unit 421 can be changed more than that in the initial state, so as to reflect the magnitude of the pressing force more accurately.

In addition, since the first pressure sensing unit 421 has an elliptical winding shape, the pattern density of the first pressure sensing unit 421 is greater than that of a single long linear shape in a unit area, and thus, when the finger presses the first pressure sensing unit 421, the deformation of the first pressure sensing unit 421 is greater, and the sensitivity of the first pressure sensing unit 421 to pressure detection is higher.

Referring to fig. 6C, the first pressure-sensing unit has another modified embodiment: one of the modified embodiments is different from the first modified embodiment in that the first pressure sensing unit 421c is a broken line shape, the total length of the broken line pattern of the first pressure sensing unit 421c in a direction is the largest, the direction is the a direction, and the total length of the broken line pattern of the first pressure sensing unit 421c in the direction is the b direction, wherein the a direction is perpendicular to the b direction. The a direction of the first pressure sensing unit 421c is the long axis direction of the first pressure sensing unit 421c, and the b direction of the first pressure sensing unit 421c is the short axis direction of the first pressure sensing unit 421 c.

After the first pressure-sensitive unit 421c receives the pressing force, the strain amount in the direction a is greater than the strain amount in the direction b, which is beneficial to the fact that the strain generated by the pressing force applied to the first pressure-sensitive unit 421c can be reflected in one direction in a concentrated manner, so that the deformation of the first pressure-sensitive unit 421c is greater, and the magnitude of the pressing force can be reflected more accurately.

In the deformation of the pressure sensing unit, the elliptical winding shape is easier to manufacture in the process because most sections of the lead are circular arcs, and the pressure sensing unit is less prone to damage and has stronger practicability.

The shape of the first pressure sensing unit 421 may also be other linear shapes such as: a curved line (e.g., the first pressure-sensitive cell 421D in fig. 6D), a multiple-stage serial line of equal length (e.g., the first pressure-sensitive cell 421E in fig. 6E), a multiple-stage serial line of unequal length (e.g., the first pressure-sensitive cell 421F in fig. 6F), or a square-shaped line (e.g., the first pressure-sensitive cell 421G in fig. 6G). The above-described deformation of the pattern shape of the first pressure sensing unit 421 is also applicable to other embodiments of the present invention. The various definitions and modifications thereof described above with respect to the pattern shape of the first pressure sensing unit 421 are applicable to the second pressure sensing unit (not shown).

In the first to fourth embodiments of the present invention, after the laminated structure and the materials of the layers of the pressure-sensing input device are determined, the relationship between the strain value of the structure of each layer in the pressure-sensing input device and the thickness of the entire structure of the pressure-sensing input device is also determined, i.e. the number of the neutral surfaces of the entire structure of the pressure-sensing input device and the specific positions thereof are also determined.

Referring to fig. 7A, a pressure sensing input module 50 according to a fifth embodiment of the present invention includes a substrate 51, a first pressure sensing layer 52 disposed on an upper surface of the substrate 51, and a second pressure sensing layer 53 disposed on a lower surface of the substrate 51 and corresponding to the first pressure sensing layer 52, wherein an overall thickness of the first pressure sensing layer 52, the substrate 51, and the second pressure sensing layer 53 is T. The first pressure sensing layer 52 and the second pressure sensing layer 53 respectively include at least one first pressure sensing unit 521 and at least one second pressure sensing unit 531, and the first pressure sensing unit 521 and the second pressure sensing unit 531 are the same as the above embodiments, and are not described herein again.

Referring to fig. 7B, when the pressure-sensing input module 50 receives a pressing force after determining the structure and material of each layer of the complete pressure-sensing input device, the structure and corresponding strain trend relationship of each layer of the pressure-sensing input device are determined, and only the strain-thickness relationship line of the pressure-sensing input module 50 (the thickness value of the thickness is T with the abscissa of the thickness being n-m) is selected, where n corresponds to the thickness position of the first pressure-sensing layer 52 in the pressure-sensing input module 50, and m corresponds to the thickness position of the second pressure-sensing layer 53 in the pressure-sensing input module 50 (since the thickness of the first pressure-sensing layer 52 and the second pressure-sensing layer 53 is smaller than the thickness of the substrate, only one point is shown here).

As shown at vi of the strain-thickness relationship line in fig. 7B, is a first variant embodiment of a fifth embodiment pressure sensing input module 50 of the present invention: when a neutral surface of the pressure sensing input module 50 is located in the substrate 51, the strain of the first pressure sensing unit 521 is negative strain (i.e., in a compression state), and the strain of the second pressure sensing unit 531 is positive strain (i.e., in a tension state). In order to make the strain difference Δ ∈ between the first pressure-sensitive cell 521 and the second pressure-sensitive cell 531 larger, it is preferable that both the absolute value of the amount of strain of the first pressure-sensitive cell 521 and the absolute value of the amount of strain of the second pressure-sensitive cell 531 are maximized.

In order to increase the strain amount of the first pressure sensing unit 521 and the strain amount of the second pressure sensing unit 531, the magnitude of the strain difference Δ ∈ between the first pressure sensing unit and the second pressure sensing unit may be adjusted by adjusting the longitudinal direction of the first pressure sensing unit 521 and the longitudinal direction of the second pressure sensing unit 531 to be parallel to the maximum strain direction of the region where the first pressure sensing unit and the second pressure sensing unit are located, or to form a small angle therebetween.

An angle a1 is defined between the long axis direction of the first pressure sensing unit 521 and the maximum strain direction of the area where the first pressure sensing unit 521 is located. The second pressure sensitive cells 531 are arranged corresponding to the first pressure sensitive cells 521 with their long axis direction forming an angle a2 with the direction of maximum strain in their area, wherein the angle a1 and the angle a2 are not directional, i.e. they range from 0 to 90. In the present embodiment, the angle a1 and the angle a2 are preferably 0 ° -45 °, further 0 ° -20 °, further 0 ° -10 °, and most preferably 0 ° (that is, the long axis directions of the first pressure-sensitive cell 521 and the second pressure-sensitive cell 531 are respectively arranged in parallel with the maximum strain direction of the region where the two are located).

Further, when the long axis direction of the first pressure-sensitive cells 521 is the same as the maximum strain direction of the first pressure-sensitive layer 52, the absolute value of the strain amount of the first pressure-sensitive cells can be maximized; when the long axis direction of the second pressure-sensitive cells 531 is the same as the direction of maximum strain of the second pressure-sensitive layer 53, the absolute value of the amount of strain of the second pressure-sensitive cells 531 can be maximized. On the premise that the strains of the first pressure sensing unit 521 and the second pressure sensing unit 531 are positive, negative, the strain difference Δ ∈ between the first pressure sensing unit 521 and the second pressure sensing unit 531 can be larger.

In another modified embodiment, when the pressure sensing input module 50 is located in a pressure sensing input device with a single neutral plane and located on the mechanical central plane of the substrate 51, the absolute values of the strain amounts of the first pressure sensing unit and the second pressure sensing unit reach the maximum value, and the strain difference Δ ∈ between the two is maximum.

As shown at V and VII of the strain-thickness relationship curve in FIG. 7B: when none of the neutral surfaces of the pressure sensing input module 50 is located in the substrate 51 (i.e., the planes with strain ∈' 0 and strain ∈ "0 are not located in the substrate 51), the neutral surface closest to the substrate 51 is located above or below the substrate 51, and it is determined that the strain of the first pressure sensing unit 521 is negative or positive as the strain of the second pressure sensing unit 531.

As shown at V in fig. 7B, a second variant embodiment of a fifth embodiment pressure sensing input module 50 of the present invention: when the strain of the first pressure sensing element 521 is a negative strain as with the strain of the second pressure sensing element 531, in order to make the strain difference Δ ∈ between the first pressure sensing element 521 and the second pressure sensing element 531 larger, it is necessary to make the absolute value of the strain amount of the first pressure sensing element larger and the absolute value of the strain amount of the second pressure sensing element smaller, so that the strain difference Δ ∈ between the two is larger.

In order to increase the absolute value of the strain of the first pressure sensing unit 521, the angle a1 between the long axis direction of the first pressure sensing unit 521 and the maximum strain direction of the area where the first pressure sensing unit 521 is located may be selected from 0 ° to 45 °, 0 ° to 20 °, further 0 ° to 10 °, and optimally 0 ° (that is, the long axis direction of the first pressure sensing unit 521 is respectively parallel to the maximum strain direction of the area where the first pressure sensing unit 521 is located); in order to reduce the absolute value of the strain amount of the second pressure-sensitive cells 531, the angle a2 between the long axis direction of the second pressure-sensitive cells 531 and the maximum strain direction of the region where the second pressure-sensitive cells 531 are located is preferably 45 ° to 90 °, further 70 ° to 90 °, further 80 ° to 90 °, and most preferably 90 ° (i.e., the long axis direction of the second pressure-sensitive cells 531 is perpendicular to the maximum strain direction of the region where the second pressure-sensitive cells 531 are located).

As shown in fig. 8A-8B, in the present embodiment, the first pressure-sensitive layers 52 are arranged in a pattern as shown in fig. 8A, and the second pressure-sensitive layers 53 are arranged in a pattern as shown in fig. 8B.

Since the pressure-sensitive cells are subjected to the same stress under the same pressing force, the magnitude of the actual strain of the pressure-sensitive cells is related to the pattern shape, the material properties and the total length of the set pattern in the a and b directions. Therefore, in addition to adjusting the angle between the long axis direction of the pressure-sensitive cells and the maximum strain direction, the pattern shapes of the first pressure-sensitive cells 521 and the second pressure-sensitive cells 531 provided corresponding thereto may be adjusted as follows:

the pattern shapes of the first pressure sensing unit 521 and the second pressure sensing unit 531 are set to be different, and the pattern shapes should satisfy the following relationship:

L_{a above}/L_{Upper b}>L_{Lower a}/L_{Lower b}

Wherein,L_{a above}Expressed as the total length in the a direction, L, of the first pressure sensing unit 521_{Upper b}Expressed as the total length in the b direction, L, of the first pressure-sensitive cell 521_{Lower a}Expressed as the total length in the a direction, L, of the second pressure-sensitive cell 531_{Lower b}Indicated as the total length of the second pressure sensing unit 531 in the b direction.

By adjusting the relationship between the ratio of the total length of the first pressure sensing unit 521 to the second pressure sensing unit 531 in the a direction to the total length of the first pressure sensing unit 521 to the second pressure sensing unit 531, the strain of the first pressure sensing unit 521 is concentrated in one direction more than the second pressure sensing unit 531, so that a larger strain amount is obtained.

In combination with the above two adjustment methods, when the strain of the first pressure sensing unit 521 and the strain of the second pressure sensing unit 531 are both negative strains, a larger strain difference Δ ∈ can be obtained.

As shown at VII, a third alternate embodiment of a fifth embodiment pressure sensing input module 50 in accordance with the present invention: when the strain of the first pressure sensing element 521 is the same as the strain of the second pressure sensing element 531 as a positive strain, in order to increase the strain difference Δ ∈ between the first pressure sensing element 521 and the second pressure sensing element 531, it is necessary to increase the strain difference Δ ∈ between the first pressure sensing element 521 and the second pressure sensing element 531 by decreasing the absolute value of the strain amount of the first pressure sensing element 521 and increasing the absolute value of the strain amount of the second pressure sensing element 531.

The present modified embodiment differs from the above-described second modified embodiment in that:

the angle a1 between the long axis direction of the first pressure-sensing unit 521 and the maximum strain direction of the area where the first pressure-sensing unit 521 is located is preferably 45 ° -90 °, further 70 ° -90 °, further 80 ° -90 °, and most preferably 90 ° (i.e. the long axis direction of the first pressure-sensing unit 521 is perpendicular to the maximum strain direction of the area where the first pressure-sensing unit 521 is located); the angle a2 between the major axis direction of the second pressure-sensitive cells 531 and the maximum strain direction of the area where the second pressure-sensitive cells 531 are located is preferably 0 ° to 45 °, further 0 ° to 20 °, further 0 ° to 10 °, and most preferably 0 ° (i.e., the major axis direction of the second pressure-sensitive cells 531 are respectively arranged parallel to the maximum strain direction of the area where the second pressure-sensitive cells are located). In the present embodiment, the first pressure-sensitive layers 52 are arranged in a pattern as shown in fig. 8B, and the second pressure-sensitive layers 53 are arranged in a pattern as shown in fig. 8A.

L_{a above}/L_{Upper b}＜L_{Lower a}/L_{Lower b}

Wherein L is_{A above}Expressed as the total length in the a direction, L, of the first pressure sensing unit 521_{Upper b}Expressed as the total length in the b direction, L, of the first pressure-sensitive cell 521_{Lower a}Expressed as the total length in the a direction, L, of the second pressure-sensitive cell 531_{Lower b}Indicated as the total length of the second pressure sensing unit 531 in the b direction.

The rest of the description is the same as the second modified embodiment, and is not repeated here. In combination with the above two adjustment methods, when the strain of the first pressure-sensitive cells 521 and the strain of the second pressure-sensitive cells 531 are both positive strains, a larger strain difference Δ ∈ can be obtained.

Compared with the prior art, the pressure sensing input module 10(40 or 50) or the pressure sensing input device 20 provided by the invention has at least the following advantages:

1. the invention provides a pressure sensing input module 10 with a temperature compensation function, which comprises a first pressure sensing unit 121 and a second pressure sensing unit 131 which are arranged on the upper surface and the lower surface of a substrate 11, wherein the first pressure sensing unit 121 and the second pressure sensing unit 131 are arranged correspondingly and have the same material, at least one first pressure sensing unit 121 and the second pressure sensing unit 131 arranged correspondingly form a Wheatstone bridge with two peripheral reference resistors (a resistor Ra and a resistor Rb).

The Wheatstone bridge is adopted to detect the pressing force value, and the circuit structure is simple and the control precision is high. Since the materials of the first pressure sensing unit 121 and the second pressure sensing unit 131 are the same, the variation of the resistance values of the first pressure sensing unit 121 and the second pressure sensing unit 131 due to the temperature variation satisfies (RF0+ Δ RF0)/(RC0+ Δ RC0) ═ RF0/RC0, and as the first pressure sensing unit 121 and the second pressure sensing unit 131 are made of the same material and jointly form a wheatstone bridge, the influence of the temperature on the resistance values of the first pressure sensing unit 121 and the second pressure sensing unit 131 can be ignored during the measurement of the resistance values, and thus the pressure sensing input module 10 provided by the present invention can completely compensate the variation of the resistance values due to the temperature.

2. In the pressure-sensing input device 20 provided by the present invention, the young's moduli and thicknesses of the substrate 201 and the adhesive layer 22 affect the neutral plane of the pressure-sensing input device 20, and when the neutral plane is located in the substrate 201, the strain difference between the first pressure-sensing unit 211 and the second pressure-sensing unit 212 disposed on the upper and lower main surfaces of the substrate 201 can reach a maximum value. Therefore, if the young's modulus of the substrate 201 is set to be larger than the young's modulus of the adhesive layer 22 by at least one order of magnitude: (1) controlling the Young's modulus of the adhesive layer 22 within the range of 100-3000MPa is beneficial to increasing the strain difference delta epsilon; (2) when the thickness of adhesive layer 22 is limited to be in the range of 25-125 μm, strain difference Δ ∈ tends to increase as the thickness of adhesive layer 22 decreases; (3) when the thickness of the substrate 201 is limited to the range of 50 to 450 μm, the strain difference Δ ∈ tends to increase as the thickness of the substrate 201 increases. Therefore, by adjusting the young's modulus and the thickness of the substrate 201 and the adhesive layer 22 of the pressure sensing input device 20, the strain difference of the pressure sensing units on the upper and lower surfaces of the substrate 201 can be increased, so that the pressure magnitude detection is more accurate, and the pressing force detection is more sensitive.

3. In the pressure sensing input module 40 provided by the present invention, the first pressure sensing unit 421 and the second pressure sensing unit are designed to have a long axis direction and a short axis direction, and the total length of the long axis direction is larger than the total length of the short axis direction. In the present invention, the pattern shapes of the first pressure-sensitive cells 421 and the second pressure-sensitive cells include elliptical winding lines, zigzag lines, curved lines, long-length multi-segment series lines, unequal-length multi-segment series lines, zigzag lines, and the like. When the first pressure sensing unit 421 or the second pressure sensing unit deforms due to finger pressing (point pressing), the first pressure sensing unit 421 or the second pressure sensing unit has different strains in the a direction and the b direction because the total length in the a direction of the major axis is different from the total length in the b direction of the minor axis, so that the effect of changing the resistance value can be effectively increased, and the response of the first pressure sensing layer or the second pressure sensing layer to the pressure is more accurate and sensitive.

4. In the pressure sensing input module 50 provided by the present invention, in order to achieve that the difference between the strain of the first pressure sensing unit 521 and the strain of the second pressure sensing unit 531 can reach a larger value, so as to improve the pressure detection sensitivity of the pressure sensing input module 50, the strain amounts of the first pressure sensing unit 521 and the second pressure sensing unit 531 can be increased or decreased by adjusting the pattern shapes of the first pressure sensing unit 521 and the second pressure sensing unit 531, and also by adjusting the arrangement manner of the first pressure sensing unit 521 and the second pressure sensing unit 531. Wherein the angle a1 ranges from the angle a2 to 0 ° -45 ° when the strains of the first pressure sensing unit 521 and the second pressure sensing unit 531 are positive and negative, the angle a1 ranges from 0 ° -45 ° and the angle a2 ranges from 45 ° -90 ° when the strains are simultaneously negative, or the angle a1 ranges from 45 ° -90 ° and the angle a2 ranges from 0 ° -45 ° when the strains are simultaneously positive. In addition, in order to make the strain difference Δ ∈ between the first pressure sensing unit 521 and the second pressure sensing unit 531 large, the pattern shape relationship between the first pressure sensing unit 521 and the second pressure sensing unit 531 may be defined. The above-described limitations can maximize the strain change values of the first pressure sensing unit 521 and the second pressure sensing unit 531. After the first pressure sensing unit 521 receives the pressing force, the strain amount in the direction a is greater than the strain amount in the direction b, which is beneficial for the strains generated by the pressing force applied to the first pressure sensing unit 521 and the second pressure sensing unit 531 to be concentrated in one direction, and when the direction in which the strains are concentrated is consistent with the maximum strain direction generated by the pressing force in the area, the strain difference Δ ∈ between the first pressure sensing unit 521 and the second pressure sensing unit 531 can be further increased, so that the magnitude of the pressing force can be more accurately represented, and the sensitivity of the pressure detection can be improved.

5. In the pressure sensing input modules 10, 40 and 50 and the pressure sensing input device 20 of the present invention, resistance type pressure sensing is adopted, which causes corresponding resistance value change through the shape change inside the pressure sensing unit, so as to determine the position of the pressing point and the magnitude of the pressing force according to the position and the magnitude of the variation generated by the resistance value change, and the same pressure sensing unit is used for both position detection (planar two-dimensional) and force detection (third-dimensional) calculation, thereby realizing simultaneous detection in three dimensions.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent alterations and improvements made within the spirit of the present invention are included in the protection scope of the present invention.

Claims

1. The utility model provides a pressure sensing input module, its bonds with each module through the laminating layer which characterized in that: the first pressure sensing unit and the second pressure sensing unit are arranged in a one-to-one correspondence mode and are made of the same material, and the at least one first pressure sensing unit and the second pressure sensing unit arranged in the correspondence mode form two resistors of a Wheatstone bridge, which are used for detecting the magnitude of a pressing force and compensating the resistance value change of the pressure sensing input module caused by the temperature; the laminating layer is arranged among the first pressure-sensitive layer, the second pressure-sensitive layer and other modules, the thickness of the laminating layer is 25-125 mu m, and the thickness of the substrate is 50-450 mu m.

2. The pressure sensing input module of claim 1, wherein: the pressure sensing input module further comprises a first reference resistor and a second reference resistor, and the first reference resistor, the at least one first pressure sensing unit and the second pressure sensing unit which is correspondingly arranged form a Wheatstone bridge.

3. The pressure sensing input module of claim 2, wherein: the wheatstone bridge is formed by connecting the first pressure sensing unit in series with the first reference resistor, and connecting the second pressure sensing unit correspondingly in series with the second reference resistor.

4. The pressure sensing input module of claim 2, wherein: the wheatstone bridge is formed by connecting the first pressure sensing unit with the second pressure sensing unit correspondingly arranged in series, and connecting the first reference resistor with the second reference resistor in series.

5. The pressure sensing input module of claim 1, wherein: the first pressure sensing unit array is arranged on the upper surface of the substrate, the second pressure sensing unit and the first pressure sensing unit are correspondingly arranged on the lower surface of the substrate, and the pressure sensing input module can simultaneously detect three-dimensional signals.

6. The pressure sensing input module of claim 1, wherein: the first pressure sensing unit and the second pressure sensing unit are formed by bending a piezoresistive material in the form of a conducting wire.

7. The pressure sensing input module of claim 6, wherein: the shapes of the first pressure sensing unit and the second pressure sensing unit are non-rotational symmetry figures.

8. The pressure sensing input module of claim 7, wherein: the pattern of the first pressure sensing unit and/or the second pressure sensing unit is designed to have the largest total length of the conducting wires towards a direction, the direction is the a direction of the first pressure sensing unit and/or the second pressure sensing unit, the total length of the conducting wires towards the direction, the direction is the b direction, of the pattern of the first pressure sensing unit and the second pressure sensing unit is the smallest, and the a direction is perpendicular to the b direction.

9. The pressure sensing input module of claim 8, wherein: the pattern shapes of the first pressure sensing unit and the second pressure sensing unit comprise one or the combination of an elliptic winding line shape, a broken line shape, a curve shape, an equal-length multi-section series line shape, an unequal-length multi-section series line shape or a Chinese character hui shape line shape.

10. The pressure sensing input module of claim 9, wherein: the first pressure sensing unit and the second pressure sensing unit which are correspondingly arranged are different in shape.