Jib force sensor

Abstract

The present application discloses a cantilever force sensor, which comprises an upper stack, a lower stack and a first isolation unit. The first isolation unit is arranged between the upper stack and the lower stack and on the first side of the force sensor, so that the second side of the force sensor is in a cantilever state. When the force sensor is pressed down from the top by a user, the second side of the upper stack in the cantilever state moves downward to contact the lower stack with the first isolation unit as a fulcrum, and the cantilever force sensor is started. The present application is based on the arrangement of the single-side isolation unit, so that the other side of the upper stack is in a cantilever state. Since the cantilever side of the upper stack can be pressed down to contact the lower stack with relatively small force to start the force sensor, a force sensor with relatively low turn on force is established. The present application also discloses a force sensor provided with a bottom switch.

Description

Technical Field

[0001] The present invention relates to a force sensor, in particular to a cantilever force sensor. Background Art

[0002] like Figure 1A As shown, U.S. Patent No. 8,371,174 discloses a common force sensor comprising an upper substrate 10 and a lower substrate 109, an upper electrode 11 disposed below the upper substrate 10, a lower electrode 119 disposed above the lower substrate 109, an upper piezoresistive layer 12 disposed below the upper electrode 11, and a lower piezoresistive layer 129 disposed above the lower electrode 119. A space 16 is formed between the upper piezoresistive layer 12 and the lower piezoresistive layer 129. The figure shows an annular isolation unit 15 disposed between the upper electrode 11 and the lower electrode 119; the upper electrode 11 and the lower electrode 119 are each electrically coupled to a circuit system 13.

[0003] Figure 1B for Figure 1A EE' cross-section diagram.

[0004] Figure 1B The annular isolation unit 15 is shown as a ring, surrounding the upper piezoresistive layer 12 and the lower piezoresistive layer 129. When a user applies downward force from above the force sensor, the annular isolation unit 15 resists the applied force, making it more difficult for the upper piezoresistive layer 12 and the lower piezoresistive layer 129 to be pressed into contact, or requiring a relatively large force to press the upper piezoresistive layer 12 and the lower piezoresistive layer 129 into contact.

[0005] Figure 1C The user applies a force P from above the force sensor. The center of the upper piezoresistive layer 12 deforms downward, first contacting the lower piezoresistive layer 129. At this moment, the combined thickness of the upper and lower piezoresistive layers 12, 129 is L1. As pressure continues to be applied, the output resistance R1 is determined by the resistance law: R1 = p * L1 / A.

[0006] Figure 1D A diagram showing the electrical properties of conductance / capacitance versus force for a common force sensor.

[0007] Figure 1D show Figure 1C During operation, the electrical properties of conductivity / capacity versus force. Figure 1D When the force sensor is pressed down from the top, Figure 1CWhen the user is in the turned-on position, a turn-on force starts at point P1, which is significantly greater than the zero-force point. This is because the annular isolation unit 15 resists the force applied downward from the top by the user.

[0008] A disadvantage of conventional force sensors is their relatively high activation force. This is because the annular isolation unit 15 resists the downward force applied by the user. For a long time, industry professionals have been striving to develop a force sensor with a lower activation force (turn-on force) and a higher sensitivity. The inventors of the present invention initially conceived of a force sensor with a relatively low activation force (turn-on force). Summary of the Invention

[0009] In view of the above-mentioned deficiencies in the prior art, according to an embodiment of the present invention, it is desired to provide a cantilever force sensor with a relatively small turnon force.

[0010] According to an embodiment, the present invention provides a cantilever force sensor, comprising an upper stack, a lower stack and a first isolation unit, wherein the first isolation unit is arranged between the upper stack and the lower stack and on the first side of the force sensor, so that the second side of the force sensor is in a cantilever state; when the force sensor is pressed down from above by a user, with the first isolation unit as a fulcrum, the second side of the upper stack in a cantilever state will move downward, contact the lower stack, and start the cantilever force sensor.

[0011] According to one embodiment, in the cantilever force sensor of the present invention, the upper stack includes an upper substrate, an upper electrode, and an upper piezoresistive layer stacked in sequence; the lower stack includes a lower piezoresistive layer, a lower electrode, and a lower substrate stacked in sequence.

[0012] According to one embodiment, in the cantilever force sensor of the present invention, the upper stack includes an upper substrate, an upper electrode, and an upper piezoresistive layer stacked in sequence, and the lower stack includes a lower electrode and a lower substrate stacked in sequence.

[0013] According to one embodiment, in the cantilever force sensor of the present invention, the upper stack includes an upper substrate and an upper electrode stacked in sequence; the lower stack includes a lower piezoresistive layer, a lower electrode, and a lower substrate stacked in sequence.

[0014] According to one embodiment, in the aforementioned cantilever force sensor of the present invention, the lower stack includes a pair of coplanar electrodes and a lower substrate stacked in sequence.

[0015] According to one embodiment, in the cantilever force sensor of the present invention, the upper stack includes an upper substrate and an auxiliary metal stacked in sequence; the lower stack includes a lower piezoresistive layer, a pair of coplanar electrodes, and a lower substrate stacked in sequence.

[0016] According to one embodiment, in the cantilever force sensor of the present invention, the upper stack includes an upper substrate and an upper piezoresistive layer stacked in sequence; and the lower stack includes a pair of coplanar electrodes and a lower substrate stacked in sequence.

[0017] According to one embodiment, in the cantilever force sensor of the present invention, the upper stack includes an upper substrate, an auxiliary metal, and an upper piezoresistive layer stacked in sequence; and the lower stack includes a pair of coplanar electrodes and a lower substrate stacked in sequence.

[0018] According to one embodiment, the cantilever force sensor of the present invention further comprises a bottom switch, wherein:

[0019] A first printed circuit board is disposed below the lower stack;

[0020] providing a first conductive contact on a bottom side of the lower stack;

[0021] A second conductive contact is disposed above the first printed circuit board and aligned with the first conductive contact;

[0022] The second isolation unit is disposed between the lower substrate and the first printed circuit board and is disposed on the first side of the force sensor;

[0023] The lower substrate, the first conductive contact, the second conductive contact and the first printed circuit board constitute a bottom switch.

[0024] According to one embodiment, in the cantilever force sensor of the present invention, the first conductive contact slightly contacts the second conductive contact; when the user presses down from the upper end of the force sensor, the first conductive contact firmly contacts the second conductive contact to activate the bottom switch.

[0025] According to one embodiment, in the cantilever force sensor of the present invention, the first conductive contact is slightly away from the second conductive contact; when the user presses down from the upper end of the force sensor, the first conductive contact firmly contacts the second conductive contact and activates the bottom switch.

[0026] According to one embodiment, in the aforementioned cantilever force sensor of the present invention, the upper piezoresistive layer or the lower piezoresistive layer is selected from piezoelectric materials, friction materials, resistance materials, and dielectric materials.

[0027] According to an embodiment, the present invention provides a force sensor provided with a bottom switch, comprising:

[0028] A first printed circuit board is disposed on the bottom of the force sensor;

[0029] a first conductive contact disposed on a bottom side of the force sensor;

[0030] a second conductive contact disposed on a top side of the first printed circuit board and aligned with the first conductive contact;

[0031] The force sensor, the first conductive contact, the second conductive contact and the first printed circuit board form a bottom switch;

[0032] The first conductive contact is in one of the following two states: (1) slightly touching the second conductive contact but not activating the bottom switch; (2) slightly separated from the second conductive contact;

[0033] a fourth isolation unit, disposed between the force sensor and the first printed circuit board, and disposed on a first side of the force sensor;

[0034] When the user presses down from above the force sensor, the second side of the force sensor moves downward, causing the first conductive contact to firmly contact the second conductive contact and activate the bottom switch.

[0035] Compared to existing technologies, the present invention utilizes a single-sided isolation unit, creating a cantilevered configuration for the other side of the upper stack. This allows the cantilevered side of the upper stack to contact the lower stack with relatively little force, activating the force sensor and creating a force sensor with a relatively low turn-on force. Due to the cantilevered design of the present invention, users only need to apply relatively little force to depress one end of the cantilever, activating the sensor and measuring relatively small forces. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figures 1A-1D Shows a schematic diagram of the structure of a common force sensor, where:

[0037] Figure 1B show Figure 1A EE' cross-section;

[0038] Figure 1C Show that the user applies a force P from above the force sensor;

[0039] Figure 1D A diagram showing the electrical properties of conductance / capacitance versus force for common force sensors.

[0040] Figures 2A-2D The schematic diagram of the structure of the first embodiment of the present invention is shown, wherein:

[0041] Figure 2B show Figure 2A A-A' cross-sectional view;

[0042] Figure 2C Displays the state where the user is pressing the force sensor FS from above;

[0043] Figure 2D An electrical diagram showing the first embodiment of the present invention.

[0044] Figure 3 A diagram showing the state of the first embodiment of the present invention when it is installed in an electronic pen.

[0045] Figures 4A-4B The schematic diagram of the structure of the second embodiment of the present invention is shown, wherein:

[0046] Figure 4B show Figure 4A BB' cross-sectional view.

[0047] Figure 5 A schematic structural diagram of a third embodiment of the present invention is shown.

[0048] Figure 6 A schematic structural diagram of a fourth embodiment of the present invention is shown.

[0049] Figure 7 The fifth embodiment of the present invention and the state of being installed in an electronic pen are shown.

[0050] Figure 8 A schematic structural diagram of a sixth embodiment of the present invention is shown.

[0051] Figure 9 A schematic structural diagram of a seventh embodiment of the present invention is shown.

[0052] Figures 10A-10B The following is a schematic diagram showing the structure of an eighth embodiment of the present invention, wherein:

[0053] Figure 10A is the front view;

[0054] Figure 10B show Figure 10A side view.

[0055] Figures 11A-11B The following is a schematic diagram showing the structure of a ninth embodiment of the present invention, wherein:

[0056] Figure 11A is the front view;

[0057] Figure 11B show Figure 11A side view.

[0058] Figures 12A-12B The following is a schematic diagram showing the structure of the tenth embodiment of the present invention, wherein:

[0059] Figure 12A is the front view;

[0060] Figure 12B show Figure 12A side view.

[0061] Figures 13A-13B The structure diagram of the eleventh embodiment of the present invention is shown, wherein:

[0062] Figure 13B show Figure 13A The state of being pressed by the user.

[0063] Figures 14A-14B The structure diagram of the twelfth embodiment of the present invention is shown, wherein:

[0064] Figure 14B show Figure 14A C-C' cross-section diagram.

[0065] Figure 15 A schematic structural diagram of a thirteenth embodiment of the present invention is shown.

[0066] Figure 16 A schematic structural diagram of a fourteenth embodiment of the present invention is shown.

[0067] Figure 17 A schematic structural diagram of a fifteenth embodiment of the present invention is shown.

[0068] Among them: 20 is the upper substrate; 21 is the upper electrode; 21B is the auxiliary metal; 22 is the upper piezoresistive layer; 23 is the lower piezoresistive layer; 24 is the lower electrode; 241 and 242 are coplanar electrodes; 25 is the lower substrate; 26 is the first printed circuit board; 262 is the second printed circuit board; 30 is the force sensor; 61 is the pen tip; G1 is the first gap; G2 is the second gap; G3 is the third gap; G4 is the fourth gap; C1 is the first conductive contact; C2 is the second conductive contact; C3 is the third conductive contact; S1 is the first isolation unit; S2 is the second isolation unit; S3 is the third isolation unit; S4 is the fourth isolation unit; SW is the bottom switch. DETAILED DESCRIPTION

[0069] The present invention will be further described below in conjunction with the accompanying drawings and specific examples. These embodiments should be understood to be merely illustrative of the present invention and not intended to limit the scope of protection of the present invention. After reading the contents described herein, those skilled in the art may make various changes or modifications to the present invention, and these equivalent variations and modifications also fall within the scope defined by the claims of the present invention.

[0070] Figures 2A-2D A first embodiment of the present invention is shown.

[0071] Figure 2AThe cantilever force sensor FS is shown, with a switch SW located at its base. The force sensor FS comprises an upper stack TS and a lower stack BS. A first isolation unit S1 is positioned between the upper and lower stacks TS, forming a first gap G1 between the two stacks. The figure shows the first isolation unit S1 positioned to the right of the sensor FS, creating a cantilever shape on the left side of the upper stack TS relative to the lower stack BS.

[0072] When a user applies downward force from above the sensor FS, the left cantilever of the upper stack TS moves downward, using the first isolation unit S1 as a fulcrum, contacting the lower stack BS and activating the sensor FS. The first isolation unit S1 has an upper piezoresistive layer 22 connected to the upper stack TS at its top and a lower piezoresistive layer 23 connected to the lower stack BS at its bottom.

[0073] The upper stack TS includes an upper substrate 20, an upper electrode 21, and an upper piezoresistive layer 22 stacked in sequence, while the lower stack BS includes a lower piezoresistive layer 23, a lower electrode 24, and a lower substrate 25 stacked in sequence.

[0074] The bottom switch SW is located at the bottom of the force sensor FS. The figure shows that the first conductive contact C1 is located on the left side of the lower stack BS. The second conductive contact C2 is located above and to the left of the first printed circuit board 26 of the bottom switch SW and contacts the first conductive contact C1. The figure shows that the second isolation unit S2 is located on the right side between the lower substrate 25 and the first printed circuit board 26, and the second gap G2 is formed between the force sensor FS and the bottom switch BS. The first conductive contact C1 and the second conductive contact C2 are located to the left of the second gap G2. The first conductive contact C1, the second conductive contact C2, and the first printed circuit board 26 are stacked in sequence to form the bottom switch SW. The first conductive contact C1 and the second conductive contact C2 of the bottom switch SW can be designed to be slightly separated or slightly in contact, forming a delay switch. This delay switch can block the initial noise signal when the force sensor FS is pressed.

[0075] In one design, the first conductive contact C1 lightly contacts the second conductive contact C2 without activating the bottom switch SW. When the user applies force from above the force sensor FS, the force sensor FS moves downward, causing the first conductive contact C1 to firmly contact the second conductive contact C2, turning on the bottom switch SW.

[0076] Figure 2B show Figure 2A The figure shows that the first isolation unit S1 is disposed on the right side of the force sensor FS and between the upper stack TS and the lower stack BS of the force sensor FS.

[0077] Figure 2C This image shows the user pressing down on the force sensor FS. When applied from above, the first isolation unit S1 acts as a fulcrum, causing the left side of the upper stack TS to move downward. The upper stack TS then contacts the lower stack BS, generating a force signal that is sent to the control center (not shown) for further processing.

[0078] Figure 2D The electrical diagram of the first embodiment of the present invention is shown, showing a curve of conductivity / capacity versus force. Figure 2C When a user applies a force P from above the force sensor FS, the pressure sensor FS is activated at point P2, which is very close to zero. This is because the force sensor FS is supported by the right isolation unit S1, allowing the left cantilever to be easily depressed. The cantilever structure of the present invention allows the upper stack TS of the force sensor FS to be easily depressed, allowing the force sensor FS to be activated with relatively little force.

[0079] Figure 3 The first embodiment of the present invention is shown in the state of being installed in an electronic pen.

[0080] Figure 3 The force sensor FS is shown to have a bottom switch SW, which is arranged at the base of the pen tip 61 of the electronic pen. When the user writes with the electronic pen, the force of the pen tip 61 can be sensed and provided to the processing unit for further signal processing.

[0081] Figures 4A-4B A second embodiment of the present invention is shown.

[0082] Figure 4A A modified embodiment is shown, which is a modification of the first embodiment of the present invention. Figure 2A The first isolation unit S1 is shown as a modified embodiment of the present invention. The first isolation unit S1 is disposed between the upper stack TS and the lower stack BS. The isolation unit S1 has a top end connected to the upper substrate 20 and a bottom end connected to the lower substrate 25.

[0083] Figure 4B show Figure 4A The figure shows a cross-sectional view taken along line BB' of FIG. The figure shows that the first isolation unit S1 is disposed on the right side of the force sensor FS and between the upper stack TS and the lower stack BS.

[0084] Figure 5 A third embodiment of the present invention is shown.

[0085] Figure 5 A further improved embodiment is shown in the figure, in which the setting position of the first isolation unit S1 is different from that of the first embodiment. Figure 5The first isolation unit S1 is shown to be disposed between the upper stack TS and the lower stack BS. The isolation unit S1 has a top end connected to the upper piezoresistive layer 22 and a bottom end connected to the lower substrate 25 .

[0086] Figure 6 A fourth embodiment of the present invention is shown.

[0087] Figure 6 A further improved embodiment is shown, in which the position of the first isolation unit S1 differs from that of the first embodiment. The figure shows that the first isolation unit S1 is disposed between the upper stack TS and the lower stack BS; the isolation unit S1 has a top end connected to the upper substrate 20 and a bottom end connected to the lower piezoresistive layer 23.

[0088] Figure 7 A fifth embodiment of the present invention is shown.

[0089] Figure 7 The figure shows the state of the force sensor FS installed in the electronic pen. A bottom switch SW is installed below the force sensor FS, which is installed in an electronic pen. The force sensor FS and bottom switch SW are located below the pen tip 61 of the electronic pen and receive pressure signals from the pen tip 61. When the user writes with the electronic pen, the force of the pen tip 61 is transmitted to a controller (not shown) for further signal processing. The figure shows the first conductive contact C1 and the second conductive contact C2 slightly separated. When the user applies force from above the force sensor FS, the left cantilever of the upper stack TS first contacts the lower stack BS, which then moves downward, causing the first conductive contact C1 to firmly contact the second conductive contact C2, thereby activating the bottom switch SW. The delay switch here is designed to shield the initial noise signal of the force sensor FS during the initial stage when the force sensor FS is pressed.

[0090] Figure 8 A sixth embodiment of the present invention is shown.

[0091] Figure 8 A further improvement to the first embodiment is shown. A single piezoresistive layer, namely an upper piezoresistive layer 22, is provided in the force sensor FS. The upper stack TS is composed of an upper substrate 20, an upper electrode 21, and an upper piezoresistive layer 22, stacked in sequence. The lower stack BS includes a lower electrode 24 and a lower substrate 25, stacked in sequence; no piezoresistive layer is provided in the lower stack BS.

[0092] The first isolation unit S1 is disposed between the upper stack TS and the lower stack BS, to the right of the force sensor FS. The first isolation unit S1 has a top end connected to the upper piezoresistive layer 22 and a bottom end connected to the lower electrode 24. The placement of the first isolation unit S1 creates a first gap G1 between the upper stack TS and the lower stack BS, allowing the left side of the upper stack TS to appear cantilevered.

[0093] Figure 9 A seventh embodiment of the present invention is shown.

[0094] Figure 9 A modified embodiment is shown. The figure shows a single piezoresistive layer, namely the lower piezoresistive layer 23. The upper stack TS provided in the force sensor FS is composed of an upper substrate 20 and an upper electrode 21 stacked in sequence. The lower stack BS is composed of the lower piezoresistive layer 23, a lower electrode 24, and a lower substrate 25 stacked in sequence.

[0095] The first isolation unit S1 is positioned between the upper stack TS and the lower stack BS, to the right of the force sensor FS. The top end of the first isolation unit S1 is connected to the upper electrode 21, and the bottom end is connected to the lower piezoresistive layer 23. This first isolation unit S1 creates a first gap G1 between the upper stack TS and the lower stack BS, giving the left side of the upper stack TS a cantilevered shape.

[0096] Figures 10A-10B An eighth embodiment of the present invention is shown.

[0097] FIG10 shows a modified embodiment of the first embodiment. Figure 10A A front view of an improved embodiment is shown, in which a single piezoresistive layer, namely the lower piezoresistive layer 23, is arranged above the lower stack BS of the force sensor FS, a pair of coplanar electrodes 241 and 242 are arranged below the lower piezoresistive layer 23, and a lower substrate 25 is arranged below the coplanar electrodes 241 and 242.

[0098] The top stack TS is composed of a top substrate 20 and an auxiliary metal 21B stacked in sequence. When the force sensor FS is pressed, the auxiliary metal 21B provides electrical conductivity. The bottom stack BS is composed of a piezoresistive layer 23, coplanar electrodes 241 and 242, and a bottom substrate 25 stacked in sequence.

[0099] Figure 10B show Figure 10AA side view of the force sensor FS. The first isolation unit S1 is positioned between the upper stack TS and the lower stack BS, to the right of the force sensor FS. The placement of the first isolation unit S1 creates a first gap G1 between the upper stack TS and the lower stack BS. The first isolation unit S1 has a top end connected to the auxiliary metal 21B and a bottom end connected to the lower piezoresistive layer 23.

[0100] Figures 11A-11B A ninth embodiment of the present invention is shown.

[0101] Figure 11A A modified embodiment of the first embodiment is shown. Figure 11A A front view of an improved embodiment is shown, wherein a single piezoresistive layer, namely an upper piezoresistive layer 22 is provided in the force sensor FS. A pair of coplanar electrodes 241 , 242 are provided above the lower substrate 25 .

[0102] The upper stack TS is formed by stacking the upper substrate 20 and the upper piezoresistive layer 22 in sequence. The lower stack BS is formed by stacking the coplanar electrodes 241 and 242 and the lower substrate 25 in sequence.

[0103] Figure 11B show Figure 11A A side view of the force sensor FS shows a first isolation unit S1 positioned between the upper stack TS and the lower stack BS, to the right of the force sensor FS. The placement of the first isolation unit S1 creates a first gap G1 between the upper stack TS and the lower stack BS. The first isolation unit S1 has a top end connected to the upper piezoresistive layer 22 and a bottom end connected to the coplanar electrodes 241 and 242.

[0104] Figures 12A-12B A tenth embodiment of the present invention is shown.

[0105] Figure 12A A modified embodiment of the first embodiment is shown. Figure 12A A front view of an improved embodiment is shown, wherein a single piezoresistive layer, namely an upper piezoresistive layer 22 is provided in the force sensor FS. A pair of coplanar electrodes 241 , 242 are provided above the lower substrate 25 .

[0106] The top stack TS is composed of a top substrate 20, an auxiliary metal 21B, and a top piezoresistive layer 22 stacked in sequence. When the force sensor FS is depressed, the auxiliary metal 21B provides electrical conductivity. The bottom stack BS is composed of a pair of coplanar electrodes 241 and 242 and a bottom substrate 25 stacked in sequence.

[0107] Figure 12B show Figure 12AA side view of the first isolation unit S1 is provided between the upper stack TS and the lower stack BS. The provision of the first isolation unit S1 creates a first gap G1 between the upper stack TS and the lower stack BS. The first isolation unit S1 has a top end connected to the upper piezoresistive layer 22 and a bottom end connected to the coplanar electrodes 241 and 242.

[0108] Figures 13A-13B An eleventh embodiment of the present invention is shown.

[0109] Figure 13A This shows an improved embodiment of the force sensor FS. A second printed circuit board 262 is disposed at the bottom of the force sensor FS. The upper stack TS is composed of an upper substrate 20, an upper electrode 21, and an upper piezoresistive layer 22 stacked in sequence. The lower stack BS is composed of a lower piezoresistive layer 23 and the second printed circuit board 262 stacked in sequence. A third conductive contact C3 is disposed above the second printed circuit board 262 and is covered by the lower piezoresistive layer 23.

[0110] The third isolation unit S3 is positioned between the upper stack TS and the lower stack BS, to the right of the force sensor FS. This creates a fourth gap G4 between the upper and lower stacks TS and BS, to the left of the force sensor FS. The third isolation unit S3 has a top end connected to the upper piezoresistive layer 22 and a bottom end connected to the lower piezoresistive layer 23.

[0111] Figure 13B show Figure 13A The state of being pressed by the user.

[0112] Figure 13B The upper stack TS is shown in a cantilevered state with the third isolation unit S3 as a fulcrum, and the left side of the upper stack TS is pressed down to contact the lower stack BS.

[0113] Figures 14A-14B A twelfth embodiment of the present invention is shown.

[0114] Figure 14A This diagram shows an improved embodiment of the cantilever force sensor of the present invention, in which the third isolation unit S3 is positioned differently. The diagram shows the third isolation unit S3 positioned between the upper stack TS and the lower stack BS, and to the right of the force sensor FS. The placement of the third isolation unit S3 creates a fourth gap G4 between the upper stack TS and the lower stack BS. The third isolation unit S3 has a top end connected to the upper substrate 20 and a bottom end connected to the second printed circuit board 262.

[0115] Figure 14B show Figure 14A C-C' cross-section diagram.

[0116] Figure 14B The third isolation unit S3 is shown disposed to the right of the force sensor FS.

[0117] Figure 15 A thirteenth embodiment of the present invention is shown.

[0118] Figure 15 This figure shows an improved embodiment of the force sensor of the present invention, in which the third isolation unit S3 is positioned differently. The figure shows the third isolation unit S3 positioned between the upper stack TS and the lower stack BS, and to the right of the force sensor FS. The placement of the third isolation unit S3 creates a fourth gap G4 between the upper stack TS and the lower stack BS. The third isolation unit S3 has a top end connected to the upper piezoresistive layer 22 and a bottom end connected to the second printed circuit board 262.

[0119] Figure 16 A fourteenth embodiment of the present invention is shown.

[0120] Figure 16 This figure shows an improved embodiment of the force sensor of the present invention, in which the third isolation unit S3 is positioned differently. The figure shows the third isolation unit S3 positioned between the upper stack TS and the lower stack BS, and to the right of the force sensor FS. The placement of the third isolation unit S3 creates a fourth gap G4 between the upper stack TS and the lower stack BS. The third isolation unit S3 has a top end connected to the upper substrate 20 and a bottom end connected to the lower piezoresistive layer 23.

[0121] Figure 17 A fifteenth embodiment of the present invention is shown.

[0122] Figure 17 A bottom switch SW is disposed below the force sensor 30. A first conductive contact C1 is disposed below the force sensor 30, and a second conductive contact C2, aligned with the first conductive contact C1, is disposed above the first printed circuit board 26. The force sensor 30, the first conductive contact C1, and the second conductive contact C2 form the bottom switch SW. The first conductive contact C1 can be designed in one of the following two ways:

[0123] (1) lightly touching the second conductive contact C2 without activating the bottom switch SW; or

[0124] (2) slightly away from the second conductive contact C2, and

[0125] The fourth isolation unit S4 is disposed between the force sensor 30 and the first printed circuit board 26, and is disposed on the right side of the force sensor 30. When a user presses down on the force sensor 30 from above, the left cantilever of the force sensor 30 moves downward, causing the first conductive contact C1 to firmly contact the second conductive contact C2, thereby activating the bottom switch SW.

[0126] The upper piezoresistive layer 22 and the lower piezoresistive layer 23 described in the present invention are merely examples. Other materials that can be used may be selected from the following groups: piezoelectric materials, friction materials, resistance materials, and dielectric materials.

Claims

1. A cantilever force sensor comprising an upper stack, a lower stack, and a first isolation unit, characterized in that: The first isolation unit is disposed between the upper stack and the lower stack and on a first side of the force sensor, so that the second side of the force sensor is in a cantilevered state. When the force sensor is pressed down from above by a user, the second side of the upper stack in the cantilevered state moves downward with the first isolation unit as a fulcrum, contacts the lower stack, and activates the cantilevered force sensor, wherein: The upper stack includes an upper substrate, an upper electrode and an upper piezoresistive layer, which are stacked in sequence; the lower stack includes a lower piezoresistive layer, a lower electrode and a lower substrate, which are stacked in sequence; Alternatively, the upper stack includes an upper substrate, an upper electrode, and an upper piezoresistive layer, which are stacked in sequence, and the lower stack includes a lower electrode and a lower substrate, which are stacked in sequence; Alternatively, the upper stack includes an upper substrate and an upper electrode, which are stacked in sequence; and the lower stack includes a lower piezoresistive layer, a lower electrode, and a lower substrate, which are stacked in sequence; or the lower stack includes a pair of coplanar electrodes and a lower substrate, stacked in sequence; Alternatively, the upper stack includes an upper substrate and an auxiliary metal, which are stacked in sequence; and the lower stack includes a lower piezoresistive layer, a pair of coplanar electrodes, and a lower substrate, which are stacked in sequence; Alternatively, the upper stack includes an upper substrate and an upper piezoresistive layer, which are stacked in sequence; and the lower stack includes a pair of coplanar electrodes and a lower substrate, which are stacked in sequence; Alternatively, the upper stack includes an upper substrate, an auxiliary metal and an upper piezoresistive layer, which are stacked in sequence; and the lower stack includes a pair of coplanar electrodes and a lower substrate, which are stacked in sequence.

2. The cantilever force sensor according to claim 1, wherein: Further comprising a bottom switch, wherein: a first printed circuit board, disposed below the cantilever force sensor; providing a first conductive contact on a bottom side of the lower stack; A second conductive contact is disposed above the first printed circuit board and aligned with the first conductive contact; The second isolation unit is disposed between the lower substrate and the first printed circuit board and is disposed on the first side of the force sensor; The lower substrate, the first conductive contact, the second conductive contact and the first printed circuit board constitute a bottom switch.

3. The cantilever force sensor according to claim 2, wherein: The first conductive contact slightly contacts the second conductive contact; when the user presses down from the upper end of the force sensor, the first conductive contact firmly contacts the second conductive contact to activate the bottom switch.

4. The cantilever force sensor according to claim 2, wherein: The first conductive contact is slightly away from the second conductive contact; when the user presses down from the upper end of the force sensor, the first conductive contact firmly contacts the second conductive contact and activates the bottom switch.

5. The cantilever force sensor according to claim 1, wherein: The lower stack includes a second printed circuit board disposed on the bottom side.

6. The cantilever force sensor according to any one of claims 1 to 5, wherein: The upper piezoresistive layer or the lower piezoresistive layer is selected from piezoelectric materials, friction materials, resistance materials and dielectric materials.

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