CN112486351A

CN112486351A - Pressure sensing device and touch panel

Info

Publication number: CN112486351A
Application number: CN202011357280.3A
Authority: CN
Inventors: 廖光睿; 黎泽宇; 白文风
Original assignee: Shenzhen Ruihu Tech Co ltd
Current assignee: Shenzhen Ruihu Tech Co ltd
Priority date: 2020-11-27
Filing date: 2020-11-27
Publication date: 2021-03-12

Abstract

The application provides a pressure sensing device, which comprises a strain layer and a detection layer; the strain layer consists of copper-clad areas positioned on the same horizontal position and at least one non-copper-clad area positioned outside the copper-clad areas at intervals, each non-copper-clad area and the copper-clad areas around the non-copper-clad area form a pressure sensing area, and the elastic modulus of the non-copper-clad areas is smaller than that of the copper-clad areas; the detection layer abutted with the strain layer consists of a bridge circuit, the bridge circuit comprises at least one variable resistor and a connecting circuit, and the projection of the variable resistor in the vertical direction is overlapped with a non-copper-coated area; the pressure sensing device further comprises a flexible isolation layer located between the strain layer and the circuit layer. The pressure sensing device is lighter and thinner on the whole, and the setting position of the resistor is suitable for various bridge circuits. In addition, a touch panel comprising the pressure sensing device is also provided.

Description

Pressure sensing device and touch panel

Technical Field

The invention belongs to the technical field of pressure sensing, and particularly relates to a pressure sensing device and a touch panel.

Background

The touch panel has a wide application range, and is applied to door control, cash dispensers, household appliances and consumer electronics products in a pressure key input mode. At present, the most widely used key panel is provided with mechanical keys, but the mechanical keys are complex in structure, a certain gap needs to be reserved between the keys and the panel, and a certain pressing stroke is needed to ensure smooth movement of the keys, so that dust is easily accumulated, fatigue damage is easily caused, the service life is influenced, and finally the keys are in failure or damage. In addition, if the mechanical keys meet water vapor and oil stain, the circuit board is easy to damage, and safety accidents are caused; in order to prevent water and oil, a more complicated waterproof structure and an additional waterproof seal are often required, resulting in increased cost and difficulty in installation. At present, in a high-end market, in order to improve sensory experience and dustproof performance, products using capacitive touch panels in batches are available. However, similarly, the capacitive touch panel is not sensitive to sensing or even fails to control when it is in a place with high humidity or when it is in contact with water or oil, and cannot be operated in a scene with gloves.

Therefore, the touch panel has higher sensitivity while meeting the requirements of water resistance, oil resistance and dust resistance. In the prior art, a pressure-sensitive touch panel is used, and a typical mode adopts a discrete pressure sensor and an electronic device disclosed in chinese patent CN105518586B to construct a hollow area on a rigid single-layer force-concentrating sensing plate, so as to obtain a cantilever structure capable of concentrating force; another pressure sensing device and electronic equipment disclosed in chinese patent CN211264283U is composed of rigid structures arranged at intervals, a flexible insulating layer on at least one mounting surface of the rigid structures, and four mechanical sensors on the flexible insulating layer, wherein the mechanical sensors are connected by circuit layers on the flexible insulating layer, and the mechanical sensors are arranged at intervals corresponding to the rigid blocks. In the scheme, the rigid block and the soft insulating layer which are abutted with each other are utilized, the rigid block is harder, the soft insulating layer is softer, so that when a pressing panel abutted with the rigid structure receives external pressing, as the stress of the rigid block is concentrated at the interval, the soft insulating layer has larger deformation compared with the rigid structure, the deformation of the pressure sensor at the strain amplification area is also larger, when the rigid body is arched upwards, the mechanical inductor above the neutral plane is stretched, the mechanical inductor below the neutral plane is compressed, and the neutral plane at the interval of the rigid block moves downwards, so that the deviation between the neutral plane of the rigid block and the neutral plane at the interval is caused. Therefore, when the half-bridge circuit is arranged, one group of resistors is arranged in the interval area, and one group of resistors is arranged corresponding to the rigid block. When the full-bridge circuit is arranged, the two groups of resistors are respectively arranged corresponding to the spacing areas of the two mounting surfaces. In this solution, the rigid block is a structure having a certain rigidity and thickness, such as a copper sheet, and the role of the rigid block in the patent is important. On one hand, a rigid structure is needed to provide a supporting effect for the soft insulating layer, and meanwhile, the deformation of the rigid block is almost ignored, so that the spacer region forms a strain concentration region; on the other hand, the neutral plane position of the strain concentration region (gap) changes, and the distances of the resistances of the upper and lower mounting surfaces from the neutral plane are different, thereby further causing the distortion. Therefore, the pressure sensing device must have rigid blocks and intervals, and the whole thickness is larger; in addition, for a full-bridge circuit, the resistance values of the four variable resistors are required to be changed, the resistance values cannot be all the same when pressure is sensed, and the four resistors cannot be located on the same mounting surface because the deformation of the rigid block is almost ignored. In this case, it is necessary to provide the flexible layer and the connection circuit on both mounting surfaces of the rigid structure, and to connect the connection circuits on both surfaces by providing a conductor such as a hole.

In conclusion, the existing pressure sensing devices respectively or simultaneously have the problems of water and oil resistance, fatigue damage, failure in case of high humidity, large volume, light and thin property, application scene limitation and the like. Therefore, there is a need in the art for a pressure sensing device that is waterproof, oil-proof, long-lived, adaptable to harsh environments, lighter, thinner, and more portable.

Disclosure of Invention

Accordingly, the present invention is directed to a thinner and more flexible pressure sensing device and a touch panel that at least solve the above-mentioned problems.

In a first aspect, a pressure sensing device is provided, which includes a strain layer, a detection layer;

the strain layer consists of copper-clad areas positioned at the same horizontal position and at least one non-copper-clad area positioned outside the copper-clad areas at intervals, each non-copper-clad area and the copper-clad areas around the non-copper-clad area form a pressure induction area, and the elastic modulus of the non-copper-clad areas is smaller than that of the copper-clad areas;

the detection layer is abutted against one surface of the strain layer and consists of a bridge circuit, the bridge circuit comprises at least one variable resistor and a connecting circuit, and the projection of the variable resistor in the vertical direction is overlapped with a non-copper-coated area;

the pressure sensing device further comprises a flexible isolation layer located between the strain layer and the circuit layer.

In this scheme, only constitute by strain layer, detection layer and isolation layer, the induction system of constitution is flexible, does not need to set up rigid bearing structure promptly, and when receiving the exogenic action, the deformation direction of each layer of pressure-sensitive device is unanimous. The strain layer is composed of a copper-clad region and a non-copper-clad region having different elastic moduli, and the projection of the variable resistor in the vertical direction overlaps the non-copper-clad region. Note that copper clad herein does not have rigidity and may be copper foil or the like. When the strain layer is acted by external force, the copper-clad area and the non-copper-clad area are deformed, and the deformation of the copper-clad area is larger than that of the non-copper-clad area because the elastic modulus of the transverse copper-clad area is larger than that of the non-copper-clad area, and the non-copper-clad area is a stress concentration area. Whether for a single bridge circuit, a half bridge circuit, or a full bridge circuit, all resistors are located on only one side of the strained layer. Taking a full-bridge circuit as an example, the detection layer comprises 4 variable resistors, and it can be understood that the variable resistors refer to resistors with resistance values changing along with self deformation, all the variable resistors are located on one side of the copper-clad area, the projection of one group of resistors in the vertical direction is overlapped with the non-copper-clad area, and the other group of resistors is completely located in the copper-clad area. The former group of resistors and the latter group of resistors are deformed simultaneously, the deformation of the former group of resistors is larger than that of the latter group of resistors, namely the resistance value change of the former group of resistors is larger than that of the latter group of resistors, the connecting circuit in the detection layer generates output electric signals, and the electric signals are identified through a signal processing circuit connected with the outside. Therefore, the pressure sensing device does not need a rigid structure, is more suitable for matching with a curved pressing panel, and has smaller structural thickness. For the full-bridge circuit, the pressure sensing device has only one layer of soft isolation layer and connecting circuit compared with the prior art, and is lighter and thinner in structure, so that the connecting circuit on two sides is not required to be connected with a conductor in a punching mode like the prior art. In addition, the pressure sensing device of the application does not adopt a rigid member, so that the application scenes are wider, such as the application of the pressure sensing device to a curved pressing panel.

In one possible embodiment, the flexible isolation layer and the connection circuit form a flexible circuit board.

In a possible embodiment, the projections of the contacts of the variable resistor in the vertical direction are all located in the copper-clad regions, and the variable resistor is arranged in a mode of crossing the non-copper-clad regions.

In one possible embodiment, the projection of the variable resistor in the vertical direction is entirely located in the non-copper-clad region.

In one possible embodiment, the non-copper-clad region is rectangular, and the variable resistor is perpendicular to the length direction of the rectangle.

In one possible embodiment, the non-copper-clad region is an ellipse, and the variable resistor is perpendicular to the long axis direction of the ellipse.

In one possible embodiment, the non-copper-clad region is i-shaped.

In one possible embodiment, the non-copper-clad region is made of polyimide.

In one possible embodiment, the flexible barrier layer is any one of a polypropylene sheet, a high temperature resistant polyester film, and a polyimide film.

In a second aspect, a touch panel is provided, which includes a pressing panel, the pressure sensing device of the first aspect or the possible implementation manner of the first aspect, and an adhesive layer; the pressing panel is provided with at least one key sensing area for receiving external pressing; the pressure sensing area in the pressure sensing device is arranged corresponding to the position of each key sensing area.

With reference to the second aspect, in one possible implementation, the adhesive layer is any one of a double-sided adhesive tape adhesive layer, an acrylic foam adhesive layer, and a silicone adhesive layer.

In a possible embodiment, in combination with the second aspect, a rigid layer is further provided between the pressing panel and the pressure sensing device.

Drawings

FIG. 1 is a cross-sectional view of a pressure sensing device according to an embodiment of the present application;

FIG. 2 is a schematic view of a pressure sensing region according to an embodiment of the present application;

FIG. 3 is a schematic view of a pressure sensing region according to another embodiment of the present application;

FIG. 4 is a schematic view of a pressure sensing region according to another embodiment of the present application;

FIG. 5 is a schematic diagram of an embodiment of a strain layer including the pressure sensing region of FIG. 2;

FIG. 6 is a schematic diagram of an embodiment of a strain layer including the pressure sensing region of FIG. 3;

FIG. 7 is a schematic diagram of an embodiment of a strain layer including the pressure sensing region of FIG. 4;

FIG. 8 is a schematic view of a pressure sensing region according to another embodiment of the present application;

FIG. 9 is a schematic diagram of an embodiment of a strain layer including the pressure sensing region of FIG. 8;

FIG. 10 is a schematic view of a pressure sensing region according to another embodiment of the present application;

FIG. 11 is a schematic view of a pressure sensing region according to another embodiment of the present application;

FIG. 12 is a schematic diagram of an embodiment of a strain layer including the pressure sensing region of FIG. 11;

FIG. 13 is a schematic view of an assembly of a touch panel according to the present application;

fig. 14 is a schematic view of another touch panel according to the present application.

Description of the main elements

Detailed Description

In order to make the objects, principles, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration and are not intended to limit the invention, as described in this summary of the invention.

It should be particularly noted that, according to the connection or position relationship that can be determined according to the text or technical content of the specification, a part of the omitted or not-shown position change diagram is omitted for the simplicity of drawing, the omitted or not-shown position change diagram is not explicitly described in the specification, and cannot be considered to be omitted, and in the interest of brevity of description, the detailed description is not repeated one by one, and the description is unified herein.

It should be understood that the embodiments of the present application may be used in systems for sensing pressure changes, including but not limited to touch/touch press identified products. As a common application scenario, the pressure sensing apparatus provided in the embodiment of the present invention may be applied to a touch panel, including a straight-sided touch panel and a curved-sided touch panel.

In a first aspect, a pressure sensing device 30 is provided, as shown in fig. 1, 2 and 4, which is an embodiment of the present application. The pressure sensing device 30 includes a strain layer 301, a flexible isolation layer 302, and a detection layer 303 sequentially in a vertical direction. The detection layer 303 comprises four resistors 3032 (hereinafter, the variable resistor and the constant resistor are both marked as 3032 in the figure) and a connecting circuit, wherein R2 and R3 are variable resistors, the detection layer 303 is abutted with one surface of the strain layer 301, and the projection of the variable resistors in the vertical direction is overlapped with the non-copper-coated region 3012; the strain layer 301 is composed of copper-clad regions 3011 located at the same horizontal position and at least one non-copper-clad region 3012 located at intervals outside the copper-clad regions 3011, each non-copper-clad region 3012 and the copper-clad regions 3011 around the non-copper-clad region 3012 form a pressure sensing region, the elastic modulus of the non-copper-clad region 3012 is smaller than that of the copper-clad region 3011, namely the strain layer 301 comprises at least one pressure sensing region; note that the copper clad region 3011 referred to herein does not provide rigidity with copper, and may be specifically a copper foil having a thickness of 5 to 105 μm. It can be understood that, since the transverse non-copper-clad region 3012 and the copper-clad region 3011 have an elastic modulus difference, when the pressure sensing region is subjected to pressure/stress, the non-copper-clad region 3012 is a stress concentration region. The strain layer 301 abuts against an external pressing panel.

The number of the variable resistors and the positions of the resistors can be selected according to the connection type of the bridge circuit, for example, when a single bridge circuit is adopted, the number of the variable resistors is 1 when 4 resistors form the bridge circuit, and the projection of the variable resistors in the vertical direction is overlapped with the non-copper-coated region 3012; similarly, when a half-bridge circuit is used, the number of the variable resistors can be 2, and in this case, the projection of the 2 variable resistors in the vertical direction is overlapped with the non-copper-clad region 3012; when a full-bridge circuit is adopted, the number of the variable resistors can be 4, at this time, the projection of 2 variable resistors in the vertical direction is overlapped with the non-copper-clad region 3012, and the other 2 variable resistors are not overlapped with the non-copper-clad region 3012, that is, the projection of the variable resistors in the vertical direction completely falls into the copper-clad region 3011. It will be understood by those skilled in the art that other undefined resistors in the bridge circuits described above are invariant resistors, and the projection of the invariant resistors in the vertical direction as a whole completely falls into the copper-clad region 3011. Then, when the strained layer 301 receives external pressure, the non-copper-clad region 3012 deforms more than the copper-clad region 3011 due to the difference in elastic modulus between the non-copper-clad region 3012 and the copper-clad region 3011, and the stress of the copper-clad region 3011 concentrates on the non-copper-clad region 3012. It should be noted that, when the pressure-sensitive region is subjected to an external force, the deformation of the copper-clad region 3011 is not negligible, so that for the full-bridge circuit, the resistance value of the variable resistor corresponding to the non-copper-clad region 3012 changes more than the resistance corresponding to the copper-clad region 3011. Therefore, in some embodiments, "greater than" herein generally means that the ratio of the two is in the same order of magnitude, i.e., the amount of deformation of the non-copper-clad region 3012 is generally within 10 times the amount of deformation of the copper-clad region 3011.

Therefore, no matter the single-bridge circuit or the half-bridge circuit, even the full-bridge circuit, all the resistor layout is located on one side of the strain layer 301 composed of the copper-clad area 3011 and the non-copper-clad area 3012, so that only one layer of the connecting circuit 3031 needs to be arranged on the side, and compared with the scheme that the resistors need to be arranged on two sides of the strain layer 301 respectively, the layout of the connecting circuit 3031 can be reduced, and the connecting circuits 3031 located on different sides can be connected. When the structure of the present application is used for manufacturing different bridge circuits, only the detection layer 303 composed of the connection lines and the resistors needs to be changed, and the operation of punching or the like on the change layer 301 is not needed to distinguish the different bridge circuits.

In the following embodiments, a half-bridge circuit is taken as an example to avoid confusion, i.e., R1 and R4 are constant resistors, and R2 and R3 are variable resistors. It is understood that, as described above, the number and arrangement of the variable resistors may be specifically determined according to the bridge circuit.

Further, a flexible isolation layer 302 is disposed between the strain layer 301 and the detection layer 303, and in one embodiment, as shown in fig. 1, the pressure sensing device 30 has a structure including a resistor, a connection line, the flexible isolation layer 302, and the strain layer 301 from top to bottom in the vertical direction. The main function of the flexible isolation layer 302 is to isolate the connection circuit from the copper foil, and simultaneously transmit the strain of the strain layer 301 to the resistor of the detection layer 303, so that the variable resistor deforms accordingly. In some embodiments, the non-copper-clad region 3012 is made of any material selected from polypropylene, high temperature resistant polyester, and polyimide, and the flexible insulating layer 302 can be understood as a polyimide film. Then, in a further embodiment, during the manufacturing process, the non-copper-clad region 3012 is filled with polyimide, and then the same material is laminated on one side of the strained layer 301 to form the soft isolation layer 302. In other embodiments, the non-copper-clad region 3012 is hollow, and the soft barrier layer 302 is used to attach the copper-clad region 3011.

It is understood that, as another alternative embodiment, in order to make the structure of the pressure sensing device 30 more compact, the structure formed by the connection Circuit and the Flexible isolation layer 302 may be an integral Flexible Circuit Board (FPC), that is, the connection Circuit and the Flexible isolation layer 302 are not separated from each other, and both are applied as an integral, at this time, in an embodiment, the electrical signal generated by the detected resistor is transmitted to the external main control Board through a gold-plated connector (gold finger) by the integral Flexible Circuit Board, and is converted into the corresponding pressing position and the pressure value through an algorithm, and it belongs to the prior art that the pressure value is obtained through the electrical signal. Then, in conjunction with the embodiment of fig. 1, the present application structurally reduces at least one flexible insulating layer and the connection circuit 3031 compared to the prior art, which can also be understood as reducing at least one flexible circuit board.

Meanwhile, since the strain layer 301 is a non-rigid layer, the pressure detection device in the above embodiment is flexible as a whole, that is, when a pressure sensing area composed of the non-copper-clad area 3012 and the copper-clad area 3011 around the non-copper-clad area 3012 is subjected to a force, the whole pressure sensing area is deformed, and the difference is that the deformation amount of the copper-clad area 3011 is different from the deformation amount of the non-copper-clad area 3012. Therefore, the pressure detection device provided by the application has the characteristics of flexibility, lightness and thinness, can be used for detecting the receiving pressure of the non-planar pressing panel, and is more compact in non-planar attaching performance. More specifically, the device can be used for fitting a curved surface with a certain radian.

As shown in fig. 2, which is a schematic diagram of a pressure sensing region formed by a non-copper-clad region 3012 and a copper-clad region 3011 around the non-copper-clad region, as an alternative embodiment, the non-copper-clad region 3012 has a rectangular shape, and in order to provide a certain space for the strain layer 301 to deform laterally, as further shown in fig. 3, in an embodiment, radial grooves with a certain included angle are formed at the end of the rectangular non-copper-clad region 3012, and it can be understood that the grooves in the figure are also the non-copper-clad region 3012. Similarly, as shown in fig. 4, the non-copper-clad region 3012 may be formed in an "i" shape by two grooves extending from two ends of a rectangle and two ends of the rectangle, so that there is a certain deformation space when the variable resistor deforms along with the strain layer 301.

Optionally, when the strain layer 301 is provided with a plurality of pressure-sensitive regions, the strain layer 301 including the embodiments of fig. 2, 3, and 4 is respectively as shown in fig. 5, 6, and 7, and the pressure-sensitive regions are arranged in an array on the strain layer 301. For the strained layer 301 shown in fig. 5, a grid-like arrangement is more advantageous for the fabrication of the strained layer 301.

Note that the arrangement of the variable resistor is compatible with the arrangement of the non-copper-clad region 3012. As can be understood from fig. 1, the resistor is not in direct contact with the strained layer 301, and therefore, the following positional relationship between the resistor and the strained layer 301 refers to a projection in the vertical direction. With reference to fig. 1 and fig. 2, the projection of the variable resistor and the non-copper-clad region 3012 in the vertical direction has an overlapped portion, and the overlapped portion here can be understood as including that one end of the variable resistor is located in the copper-clad region 3011 and the other end is located in the non-copper-clad region 3012; the whole variable resistor is positioned in the non-copper-clad area 3012, and contacts at two ends are positioned in the non-copper-clad area 3012; the projection of the middle part of the variable resistor in the vertical direction is located in the non-copper-clad area 3012, and the two ends of the variable resistor are located in the copper-clad area 3011. As a preferred embodiment, the varistor is disposed across the width of the rectangle in fig. 2 to 7, and the contacts at both ends of the varistor are located in the copper-clad region 3011, that is, the third overlapping portion. As can be understood by those skilled in the art, as the variable resistor, the resistor is generally in a strip shape, that is, can be divided into a length direction and a width direction, the change of the resistance value of the resistor is generally caused by deformation in the length direction, the resistance value is increased when the resistor is stretched, and the resistance value is decreased when the resistor is compressed; the contacts of the resistor are located at both ends in the length direction. Therefore, in the present application, the direction of the resistor is referred to as the length direction of the resistor, and the term "across" is understood to mean that the length direction of the resistor is perpendicular to the width direction of the rectangle. Furthermore, the length of the variable resistor on two sides of the rectangle is equal, so that the variable resistor is stressed uniformly.

In another embodiment, with reference to fig. 1 and 3, in order to make the deformation of the copper-clad region 3011 more concentrated in the aforementioned rectangular region, a cantilever beam in the prior art may be used, and the pressure-sensitive region may be configured to be in the shape of an elastic arm. Correspondingly, the shape of the pressure sensing area can also be as shown in fig. 8, and based on the embodiment of the pressure sensing area in fig. 3, a "zone" -type non-copper-coated area 3012 is formed without closing the opening annular groove; a corresponding strained layer 301 comprising a plurality of pressure sensitive regions of this embodiment may be seen in fig. 9.

It should be understood that the arrangement of the variable resistor relative to the non-copper-clad region 3012 refers to the arrangement of the rectangle in fig. 2, the embodiment in fig. 3 and 4 does not change the rectangle, but only in order to make the pressure sensing region have a certain deformation space, the deformation of the copper-clad region 3011 is more concentrated to the rectangular region, so that a groove is arranged on the periphery of the rectangle, and the groove is not closed.

In another embodiment of the strained layer 301, the non-copper-clad region 3012 is an oval shape, unlike the embodiment of fig. 8 and 9. The arrangement corresponding to the variable resistor may be as shown in fig. 10 or fig. 11. In the embodiment shown in fig. 10, the projection of the variable resistor in the vertical direction is perpendicular to the long axis direction of the ellipse in the form of a crossover, and more preferably, the projection of the variable resistor in the vertical direction coincides with the short axis of the ellipse, and the contact points of the variable resistor are located in the copper-clad regions 3011 on both sides of the non-copper-clad region 3012. For the embodiment shown in fig. 11, in another possible implementation, the projections of the whole variable resistor in the vertical direction are all located in the non-copper-clad region 3012, and preferably, the variable resistor in this embodiment is arranged along the long axis direction. Fig. 12 is a schematic diagram of a strained layer 301 including the embodiment of the pressure sensitive region of fig. 11. It is understood that the contacts of the variable resistor are all located in the non-copper-clad region 3012. It should be further understood that if the full-bridge circuit is provided, since the full-bridge circuit includes 4 variable resistors, the variable resistors in the full-bridge circuit refer to only 2 resistors, and the other two variable resistors are still integrally formed in the copper-clad region 3011. In addition, similarly, for the mode that the projections of the whole variable resistor in the vertical direction are all located in the non-copper-clad region 3012, the embodiments shown in fig. 2 to 4 may also be adopted, only that the whole variable resistor is located in the rectangular region and the arrangement direction is parallel to the length direction of the rectangle.

Further, referring to fig. 1, a protective layer is further disposed outside the detection layer 303 to isolate the connection circuit 3031 and the resistor in the detection layer 303 from the external environment, and preferably, the protective layer may be a solder resist layer formed by curing a solder resist.

In a second aspect, a touch panel 1 is provided, please refer to fig. 1 and 13, including an adhesive layer 20, a pressing panel 10 and the pressure sensing device 30 of the first aspect, wherein the pressing panel 10 is provided with at least one key sensing area 101 for receiving external pressing, and the pressure sensing area in the pressure sensing device 30 is disposed corresponding to a position of each key sensing area 101. In one embodiment, the pressure sensing device 30 is bonded to the pressing panel by the adhesive layer 20, and the adhesive layer 20 may be an adhesive such as a hot-press adhesive, a metal adhesive, or a water adhesive in order to more sufficiently bond the pressure sensing device 30 to the pressing panel.

When the key sensing area 101 is pressed externally, deformation is generated, the pressure sensing area corresponding to the lower portion of the key sensing area 101 is deformed, the resistor of the detection layer 303 abutted to the strain layer 301 is deformed, the resistance value of the resistor is changed, and the connection circuit 3031 of the detection layer 303 identifies the electric signal of the deformation of the resistor 3032 through the signal processing circuit connected with the outside. As described above, if the flexible insulating layer 302 and the connection circuit 3031 are integrated into a flexible circuit board, the connection circuit 3031 transmits an electrical signal to an external circuit through the gold-plated connectors 3013 (gold fingers) on the flexible circuit board.

In practical use, the touch panel of the present application may be disposed on a mounting base 70, as shown in fig. 12, the mounting base is provided with a mounting groove 702, and optionally, the touch panel may be better attached by adhering another receiving layer 60 with good flexibility to the mounting base 70 with a low surface finish. It can be understood that the depth of the mounting groove 702 should be not less than the thickness of the receiving layer 60 and not greater than the height of the receiving layer 60 plus the touch panel, i.e. the touch panel is partially located in the mounting groove and partially higher than the mounting groove. In one possible embodiment, the mounting base further has an opening for mounting the display screen 701, so as to display the status information of the touch panel.

If the pressing panel is not suitable for the adhesive layer 20 using an adhesive, but is attached to the pressure sensing device 30 using an adhesive layer such as 3M adhesive, double-sided adhesive, etc., since such an adhesive layer is thick and soft, the slight strain of the pressing panel cannot be accurately transmitted to the pressure sensing device 30. As another alternative, with reference to fig. 1 and 14, it is necessary to add a rigid layer 50 between the pressing panel and the pressure sensing device 30, and the strain weakened by the thick and soft glue layer 40 is concentrated under the variable resistance projection by the stress concentration on the rigid layer 50, so as to improve the sensitivity and accuracy of the pressure sensing device 30. At this time, in order to ensure that the fine strain energy of the rigid layer 50 is sufficiently transmitted to the varistor, the rigid layer 50 and the strain layer 301 are bonded together by the adhesive layer 20, and similarly, the adhesive layer 20 is generally made of hot-pressing adhesive, metal adhesive, water adhesive, or the like, and the side of the rigid layer 50 away from the varistor is bonded to the pressing panel by the thick and soft adhesive layer 40.

It should be noted that, in the foregoing embodiment, each included module is only divided according to functional logic, but is not limited to the above division as long as the corresponding function can be implemented; in addition, specific names of the functional units are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present invention.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A pressure sensing device comprises a strain layer and a detection layer;

the strain layer consists of copper-clad areas positioned on the same horizontal position and at least one non-copper-clad area positioned outside the copper-clad areas at intervals, each non-copper-clad area and the copper-clad areas around the non-copper-clad area form a pressure induction area, and the elastic modulus of the non-copper-clad areas is smaller than that of the copper-clad areas;

the pressure sensing device further comprises a soft isolation layer positioned between the strain layer and the detection layer.

2. The pressure sensing device of claim 1, wherein the flexible isolation layer and the connection circuit comprise a flexible circuit board.

3. The pressure sensing device of claim 2, wherein the projections of the contacts of the variable resistor in the vertical direction are located in the copper-clad regions.

4. The pressure sensing device according to claim 2, wherein a projection of the variable resistor in a vertical direction is entirely located in the non-copper-clad region.

5. The pressure sensing device of claim 3, wherein the non-copper-clad region is rectangular and the variable resistor is perpendicular to the length direction of the rectangle.

6. The pressure sensing device of claim 3, wherein the non-copper-clad region is an ellipse, and the variable resistor is perpendicular to a major axis of the ellipse.

7. The pressure sensing device of claim 4, wherein the variable resistance is parallel to a major axis of the ellipse.

8. The pressure sensing device of any one of claims 3-7, wherein the non-copper-clad region is a polyimide material.

9. The pressure sensing device of claim 8, wherein the flexible barrier layer is any one of a polypropylene sheet, a high temperature resistant polyester film, and a polyimide film.

10. A touch panel comprising a pressing panel, the pressure-sensitive device of claim 1, 2 or 3, and an adhesive layer; the pressing panel is provided with at least one key sensing area for receiving external pressing; the pressure sensing area in the pressure sensing device is arranged corresponding to the position of each key sensing area.

11. The touch panel of claim 10, wherein a rigid layer is further disposed between the pressing panel and the pressure sensing device.