Pressure Sensing Device and Method of Manufacturing the Same

Abstract

A pressure sensing device includes a first flexible substrate, a pressure sensitive material disposed on the first flexible substrate, and a second flexible substrate disposed on the pressure sensitive material. The second flexible substrate has a first surface facing the pressure sensitive material, a second surface opposite to the first surface, and an opening extending to the first surface and the second surface. The pressure sensing device further includes an electrode group disposed in the opening and extending from the opening to the first surface and the second surface, wherein the electrode group is electrically connected to the pressure sensitive material and has a first electrode and a second electrode. The first electrode covers a part of the inner surface of the opening, a part of the first surface, and a part of the second surface. The second electrode covers a part of the inner surface of the opening, a part of the first surface, and a part of the second surface, wherein the second electrode and the first electrode are disposed opposite to each other and separated. Thereby, the accuracy of the pressure sensing device is improved to enhance the sensing accuracy of the pressure sensing device.

Description

Technical Field

[0001] The present invention relates to a pressure sensing device and a manufacturing method thereof. Background Art

[0002] A pressure sensing device can sense the pressure applied by a user thereon, and convert the deformation generated by the pressure into an electrical signal or other required forms of information for output. The signal output by the force sensing device can trigger a feedback module, thereby providing an intuitive feeling for the user. For example, a touchpad can provide different vibration feedbacks according to different pressing forces of the user. If the pressure sensing device cannot provide an accurate signal, it may cause the feedback module to fail to provide the correct feedback, resulting in incorrect perception or inconvenient operation for the user.

[0003] Therefore, various industries strive to improve the accuracy of the pressure sensing device and its process to ensure the output of accurate signals and improve the sensing accuracy of the pressure sensing device. Summary of the Invention

[0004] According to some embodiments of the present invention, a pressure sensing device includes a first flexible substrate, a pressure-sensitive material disposed on the first flexible substrate, and a second flexible substrate disposed on the pressure-sensitive material. The second flexible substrate has a first surface facing the pressure-sensitive material, a second surface opposite to the first surface, and an opening extending to the first surface and the second surface. The pressure sensing device further includes an electrode group disposed in the opening and extending from the opening to the first surface and the second surface, wherein the electrode group is electrically connected to the pressure-sensitive material and has a first electrode and a second electrode. The first electrode covers a part of the inner surface of the opening, a part of the first surface, and a part of the second surface. The second electrode covers a part of the inner surface of the opening, a part of the first surface, and a part of the second surface, wherein the second electrode and the first electrode are disposed opposite to each other and separated.

[0005] In some embodiments, in a top view of the pressure sensing device viewed from the second surface, the first electrode and the second electrode are mirror-symmetric.

[0006] In some embodiments, the first electrode has a first concave surface, and the second electrode has a second concave surface, and the first concave surface and the second concave surface face each other.

[0007] In some embodiments, the pressure-sensitive material includes an elastic resin and several conductive materials, wherein the conductive materials are distributed in the elastic resin.

[0008] In some embodiments, the conductive material includes silver.

[0009] In some embodiments, the conductive material further includes tin or bismuth.

[0010] In some embodiments, the material of the electrode group includes tin or silver.

[0011] In some embodiments, the electrode group disposed on the first surface of the second flexible substrate is in direct contact with the pressure-sensitive material.

[0012] In some embodiments, the pressure sensing device further includes a protective layer that fills the opening in the second flexible substrate and is distributed between the first electrode and the second electrode.

[0013] In some embodiments, the electrode group disposed on the inner surface of the opening is in direct contact with the protective layer.

[0014] According to some embodiments of the present invention, a method of manufacturing a pressure sensing device includes providing a first flexible substrate, disposing a pressure-sensitive material on the first flexible substrate, providing a second flexible substrate having a first surface and a second surface opposite the first surface, and forming an opening in the second flexible substrate. The opening extends to the first surface and the second surface. The method of manufacturing the pressure sensing device further includes forming a conductive layer on the inner surface and the first surface of the opening, wherein the conductive layer has a continuous edge in a top view viewed from the second surface. The method of manufacturing the pressure sensing device further includes removing a first portion and a second portion of the conductive layer such that the continuous edge of the conductive layer is disconnected to separate the first electrode and the second electrode. The method of manufacturing the pressure sensing device further includes pressing the first flexible substrate and the second flexible substrate together such that the pressure-sensitive material is electrically connected to the first electrode and the second electrode, wherein the pressure-sensitive material is interposed between the first flexible substrate and the second flexible substrate.

[0015] In some embodiments, after removing the first portion and the second portion, the first electrode and the second electrode are mirror-symmetric in a top view viewed from the second surface.

[0016] In some embodiments, forming the conductive layer includes using an electroplating process.

[0017] In some embodiments, the method of manufacturing the pressure sensing device further includes forming a silver layer or a tin layer on the first electrode and the second electrode before pressing the first flexible substrate and the second flexible substrate together.

[0018] In some embodiments, the pressing temperature of the first flexible substrate and the second flexible substrate together is in the range between 180 degrees Celsius and 260 degrees Celsius.

[0019] In some embodiments, pressing the first flexible substrate and the second flexible substrate together causes both the first electrode and the second electrode to be in direct contact with the pressure-sensitive material.

[0020] In some embodiments, the method of manufacturing the pressure sensing device further includes forming a protective layer on the second flexible substrate, wherein the protective layer is distributed between the first electrode and the second electrode.

[0021] Embodiments of the present invention provide a pressure device and a method for manufacturing the same. By pressing a first flexible substrate having a pressure-sensitive material and a second flexible substrate having an electrode group, and forming the electrode group through the same holes, the sensing accuracy of the pressure sensing device is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] When reading the following embodiments, refer to the accompanying drawings to clearly understand the concept of the present invention. It should be noted that, according to standard industry practices, various features are not drawn to scale. In fact, for the sake of clear discussion, the dimensions of various features may be arbitrarily enlarged or reduced. Furthermore, the same reference numerals represent the same elements.

[0023] Figure 1A 、 Figure 2A 、 Figure 3A 、 Figure 4A 、 Figure 5A 、 Figure 6A and Figure 7A are top views of the pressure sensing device at various manufacturing stages according to some embodiments of the present invention.

[0024] Figure 1B 、 Figure 2B 、 Figure 3B 、 Figure 4B 、 Figure 5B 、 Figure 6B and Figure 7B are cross-sectional views of the pressure sensing device along the section line A-A in the top view at various manufacturing stages according to some embodiments of the present invention. DETAILED DESCRIPTION

[0025] When an element such as a layer, film, region, or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element, or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, no intervening elements are present. As used herein, "connected" can refer to physical and / or electrical connection. Furthermore, "electrically connected" or "coupled" may mean that other elements are present between two elements.

[0026] In addition, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe the relationship of one element to another element, as shown in the figures. It should be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation shown in the figures. For example, if the device in one figure is flipped, an element described as on the "lower" side of other elements will be oriented on the "upper" side of the other elements. Thus, the exemplary term "lower" can include both the "lower" and "upper" orientations, depending on the particular orientation of the figure. Similarly, if the device in one figure is flipped, an element described as "beneath" or "under" other elements will be oriented as "above" the other elements. Thus, the exemplary terms "beneath" or "under" can include both above and below orientations.

[0027] As used herein, "about," "approximately," or "substantially" includes the stated value and an average within an acceptable deviation range of a particular value as determined by one of ordinary skill in the art, taking into account the particular amounts of the measurements and the errors associated with the measurement (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value.

[0028] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and this invention, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0029] The pressure sensing device can sense the pressure applied thereto, and convert the deformation generated by the pressure into an electrical signal or other required form of information output. Therefore, the relationship (e.g., linear relationship) of the magnitude of the external applied pressure can be obtained through the change of the electrical signal of the pressure sensing device. If the electrical signal is interfered with, the judgment of the pressure magnitude will be affected, resulting in a decrease in the sensing accuracy of the pressure conduction device. Therefore, the embodiments of the present invention provide a pressure sensing device and a manufacturing method thereof to improve the accuracy of the pressure sensing device and its process to ensure the output of accurate signals and improve the sensing accuracy of the pressure sensing device.

[0030] It should be noted that, unless otherwise specified, when the following embodiments are illustrated or described as a series of operations or events, the described order of these operations or events should not be restricted. For example, some operations or events may be performed in an order different from that of the present invention, some operations or events may occur simultaneously, some operations or events may not need to be performed, and / or some operations or events may be repeated. Also, additional operations may be required before, during, or after each step of the actual process to completely form the pressure conduction device. Therefore, some of these additional operations will be briefly described in the present invention.

[0031] Please refer to Figure 1A and Figure 1B , Figure 1A , which is a top view of a pressure sensing device in one manufacturing stage according to some embodiments of the present invention. Figure 1B is a cross-sectional view of the pressure sensing device along the Figure 1A section line A-A in. First, in step S100, a first flexible substrate 100 and a pressure-sensitive material 102 are provided, and the pressure-sensitive material 102 is disposed on the first flexible substrate 100.

[0032] The material of the first flexible substrate 100 may include a flexible polymer material, such as polyimide (PI), thermoplastic polyimide (TPI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyurethane (PU), thermoplastic polyurethane (TPU), other suitable materials, derivatives of the above, or any combination of the above materials. For example, the material of the first flexible substrate 100 may include thermoplastic polyimide (TPI).

[0033] The material of the pressure-sensitive material 102 may include an elastic resin (not shown) and several conductive materials (not shown), where the elastic resin may serve as an insulating matrix, and the conductive materials are distributed within the elastic resin to provide electrical conduction. The elastic resin of the pressure-sensitive material 102 may include polydimethylsiloxane (PDMS), thermoplastic polyurethane (TPU), polyester resin, epoxy resin, silicone resin, or other suitable materials, or any combination of the above materials. For example, the elastic resin of the pressure-sensitive material 102 may include PDMS. In some embodiments, the elastic resin in the material forming the pressure-sensitive material 102 is between 15 wt% (weight percentage) and 20 wt%. In some embodiments, the elongation rate of the elastic resin is in the range of 5% to 50%.

[0034] The conductive material of the pressure-sensitive material 102 may include metals, such as silver conductive powder, conductive silver nanowires, multi-branched silver, carbon conductive powder, conductive carbon nanotubes, nickel conductive powder, silver-coated aluminum conductive powder, silver-coated copper conductive powder, silver-coated nickel conductive powder, silver-coated glass conductive powder, other suitable metals, or any combination of the above materials. The conductive material of the pressure-sensitive material 102 may also include oxides, such as zinc oxide powder, indium tin oxide powder, ruthenium dioxide powder, other suitable materials, or any combination of the above materials. For example, the conductive material of the pressure-sensitive material 102 may include silver, such as silver conductive powder, conductive silver nanowires, multi-branched silver, silver-coated copper conductive powder, etc. The conductive material may further include tin or bismuth. For example, when the conductive material of the pressure-sensitive material 102 has silver, the conductive material of the pressure-sensitive material 102 may further have tin. In some embodiments, the conductive material in the material forming the pressure-sensitive material 102 is between 20 wt% (weight percentage) and 25 wt%.

[0035] In some other embodiments, the material forming the pressure-sensitive material 102 may also include a solvent, such as methyl ethyl ketone, isophorone, other suitable solvents, or any combination of the above materials, and the present invention is not limited thereto. In some embodiments, the solvent in the material forming the pressure-sensitive material 102 is between 55 wt% (weight percentage) and 65 wt%.

[0036] Please also refer to Figure 2A and Figure 2B , Figure 2A is a top view showing the pressure sensing device in one manufacturing stage according to some embodiments of the present invention, Figure 2B is shown according to some embodiments of the present invention along the pressure sensing device Figure 2ACross-sectional view of the cut line A-A in []. Next, in step S200, a second flexible substrate 200 is provided, which includes a first surface S1 and a second surface S2 opposite to the first surface S1.

[0037] The material of the second flexible substrate 200 may include a flexible polymer material, such as PI, TPI, PET, PEN, PU, TPU, other suitable materials, derivatives of the above, or any combination of the above materials. For example, the material of the second flexible substrate 200 may include TPI. In some embodiments, the material of the second flexible substrate 200 may be substantially the same as the material of the first flexible substrate 100.

[0038] In the embodiments shown in Figure 2A and Figure 2B , a circuit layer 202 is formed on the first surface S1 and the second surface S2 of the second flexible substrate 200. In some embodiments, the circuit layer 202 may be formed only on the first surface S1 or the second surface S2. The material of the circuit layer 202 may include metals, such as aluminum, gold, silver, copper, tin or other metals, or any combination of the above materials. In some embodiments, the circuit layer 202 may be a copper circuit. It should be noted that, in order to simplify the drawings for clear illustration, only a part of the circuit layer 202 is shown, such as the part connected to the electrode group 500 (see Figure 5A ). In actual applications, the complete circuit layer 202 can be formed according to product design or process conditions. The circuit layer 202 can be made by an additive method, a semi-additive method or a subtractive method.

[0039] Please also refer to Figure 3A and Figure 3B , Figure 3A is a top view showing the pressure sensing device in one manufacturing stage according to some embodiments of the present invention, Figure 3B is a cross-sectional view showing the pressure sensing device along the Figure 3A cut line A-A in []. Next, in step S300, a first opening O1 is formed in the second flexible substrate 200, where the first opening O1 extends to the first surface S1 and the second surface S2. In other words, the first opening O1 can be a through hole that penetrates the second flexible substrate 200, making the second flexible substrate 200 have a hollow structure connecting the first surface S1 and the second surface S2.

[0040] The shape of the first opening O1 in the top view (such as the top view seen from the second surface S2) can be circular, oval, rectangular, diamond-shaped, polygonal, or any shape with a symmetric structure, but the present invention is not limited thereto. For example, the first opening O1 can be a line-symmetric figure that has at least one axis of symmetry. If the figure of the first opening O1 is folded along the axis of symmetry, the parts on both sides of the axis of symmetry can coincide with each other. In the embodiments shown in Figure 3AIn the illustrated embodiment, the first opening O1 can be circular.

[0041] The formation method of the first opening O1 can include laser drilling, mechanical drilling, other suitable techniques, or any combination of the above materials. In some embodiments, the setting position of the first opening O1 can be within the range of the circuit layer 202, as Figure 3A shown. In some embodiments, the size of the first opening O1 is between 0.4 millimeters (mm) and 1 mm. For example, in an embodiment where the first opening O1 is circular, the diameter of the first opening O1 can be within the range of 0.4 mm to 1 mm.

[0042] Please refer to Figure 4A and Figure 4B , Figure 4A which is a top view of the pressure sensing device in one of the manufacturing stages according to some embodiments of the present invention, Figure 4B and Figure 4A is a cross-sectional view of the pressure sensing device along the section line A-A in

[0043] . Next, in step S400, the conductive layer 400 is formed on the first opening O1 and the second flexible substrate 200. Specifically, the conductive layer 400 is formed on the inner surface of the first opening O1, and on the first surface S1 and the second surface S2 adjacent to the first opening O1. Figure 4A In some embodiments, the conductive layer 400 can be a continuous film layer extending from the inner surface of the first opening O1 to the first surface S1 and the second surface S2. In some further embodiments, the conductive layer 400 completely covers the inner surface of the first opening O1 and is formed on the first surface S1 and the second surface S2 along the shape of the first opening O1. Therefore, in

[0044] the top view in

[0045] The material of the conductive layer 400 may include metals, such as aluminum, gold, silver, copper, tin, or other metals, or any combination of the above materials. In some embodiments, the material of the conductive layer 400 may include copper.

[0046] The second flexible substrate 200 may include a cutting area R, which is Figure 4A shown by a broken line. The range of the cutting area R may cover a part of the circuit layer 202 and a part of the conductive layer 400. Therefore, the conductive layer 400 can be further divided into different parts. For example, as Figure 4A shown, the conductive layer 400 may include a first part 400-1, a second part 400-2, a third part 400-3, and a fourth part 400-4, wherein the first part 400-1 and the second part 400-2 are within the range of the cutting area R, while the third part 400-3 and the fourth part 400-4 are outside the range of the cutting area R.

[0047] Please also refer to Figure 5A and Figure 5B ., Figure 5A which is a top view of the pressure sensing device in one of the manufacturing stages according to some embodiments of the present invention, Figure 5B and Figure 5A which is a cross-sectional view of the pressure sensing device along the section line A-A in Figure 4A . Then, in step S500, the cutting area R is removed, that is, a part of the second flexible substrate 200, a part of the circuit layer 202, and a part of the conductive layer 400 are removed. After the removal, a second opening O2 is formed in the second flexible substrate 200. The second opening O2 can be regarded as

[0048] the combined area of the first opening O1 and the cutting area R in

[0049] . In some embodiments, the method of removing the cutting area R may include using a punch cutting tool to align with the cutting area R and then performing punch cutting to remove the cutting area R.

[0050] Specifically, the continuous edges of the conductive layer 400 (see Figure 4A)During the removal process, the first electrode 500-1 and the second electrode 500-2 are disconnected and separated, where the first electrode 500-1 is substantially the same as the third part 400-3 and the second electrode 500-2 is substantially the same as the fourth part 400-4. Since the first electrode 500-1 and the second electrode 500-2 are separated from the conductive layer 400 (see Figure 4A ) by stamping and cutting through the same opening (e.g., the first opening O1), the first electrode 500-1 and the second electrode 500-2 are formed substantially simultaneously. The first electrode 500-1 and the second electrode 500-2 can be collectively referred to as the electrode group 500.

[0051] The distance between the first electrode 500-1 and the second electrode 500-2 in the electrode group 500 can be defined by the first opening O1. Multiple electrode groups 500 can be formed by forming multiple first openings O1. The first opening O1 can determine the configuration of the electrode group 500, and by controlling the dimensional accuracy of the first opening O1 to control the distance between the first electrode 500-1 and the second electrode 500-2, it helps to improve the consistency between the electrode groups 500.

[0052] Furthermore, the conductive layer 400 (see Figure 4A ) can be regarded as the previous stage of the electrode group 500. Therefore, except that the continuous edge of the conductive layer 400 (see Figure 4A ) is disconnected, the electrode group 500 can have the same material as the conductive layer 400 (see Figure 4A ), and the electrode group 500 can have a structure similar to that of the conductive layer 400 (see Figure 4A ), which will not be elaborated here. For example, the electrode group 500 is disposed in the second opening O2 and extends from the second opening O2 to the first surface S1 and the second surface S2. Specifically, the first electrode 500-1 in the electrode group 500 covers a part of the inner surface, a part of the first surface S1, and a part of the second surface S2 of the second opening O2, while the second electrode 500-2 in the electrode group 500 covers a part of the inner surface, a part of the first surface S1, and a part of the second surface S2 of the second opening O2, where the regions covered by the first electrode 500-1 and the second electrode 500-2 do not overlap each other.

[0053] In some embodiments, after removing the first part 400-1 and the second part 400-2 of the conductive layer 400, the first electrode 500-1 and the second electrode 500-2 formed exhibit line symmetry (or mirror symmetry), but the present invention is not limited thereto. For example, as Figure 5A shown, the reference symmetry axis 510 is between the first electrode 500-1 and the second electrode 500-2. If folded with the reference symmetry axis 510 as the center, the first electrode 500-1 and the second electrode 500-2 on both sides of the reference symmetry axis 510 can coincide with each other. In such asFigure 5A In the illustrated embodiment, the first electrode 500-1 has a first concave surface, and the second electrode 500-2 has a second concave surface, and the first concave surface and the second concave surface face each other.

[0054] Alternatively, the distance between the first electrode 500-1 and the reference symmetry axis 510 is substantially equal to the distance between the second electrode 500-2 and the reference symmetry axis 510. For example, the first electrode 500-1 is separated from the reference symmetry axis 510 by a first distance D-1, and at the corresponding position, the second electrode 500-2 is separated from the reference symmetry axis 510 by a second distance D-2, where the first distance D-1 is substantially equal to the second distance D-2.

[0055] Please also refer to Figure 6A and Figure 6B , Figure 6A which is a top view of the pressure sensing device in one of the manufacturing stages according to some embodiments of the present invention, Figure 6B and Figure 6A is a cross-sectional view of the pressure sensing device along the section line A-A in

[0056] . Then, in step S600, the first flexible substrate 100 and the second flexible substrate 200 are pressed together so that the pressure-sensitive material 102 is electrically connected to the first electrode 500-1 and the second electrode 500-2, where the pressure-sensitive material 102 is interposed between the first flexible substrate 100 and the second flexible substrate 200.

[0057] In the embodiment as shown in Figure 6B , the second flexible substrate 200 faces the pressure-sensitive material 102 with a first surface S1, so that the electrode group 500 located on the first surface S1 directly contacts the pressure-sensitive material 102, thereby electrically connecting the electrode group 500 to the pressure-sensitive material 102. In some embodiments, both the first electrode 500-1 and the second electrode 500-2 directly contact the pressure-sensitive material 102, so that the separated first electrode 500-1 and second electrode 500-2 can be electrically connected through the pressure-sensitive material 102.

[0058] The lamination temperature for laminating the first flexible substrate 100 and the second flexible substrate 200 is between approximately 180 degrees Celsius and approximately 260 degrees Celsius. For example, in some further embodiments, a lamination temperature of approximately 180 degrees Celsius may be used according to the selected material properties. During the lamination process, the material of the electrode group 500 may fuse due to contact with the conductive material of the pressure-sensitive material 102. To reduce the contact resistance between the electrode group 500 and the pressure-sensitive material 102, in some embodiments, the conductive material of the pressure-sensitive material 102 may contain silver to achieve better electrical performance after fusion. In some embodiments, the silver of the conductive material may have a tip structure (such as conductive silver nanowires, multi-branched silver, etc.), where the tip structure of the silver may preferentially fuse with the material of the electrode group 500 to reduce the contact resistance. The conductive material of the pressure-sensitive material 102 may further contain tin or bismuth to facilitate better fusion with the material of the electrode group 500 to reduce the contact resistance.

[0059] In addition to selecting materials on the conductive material of the pressure-sensitive material 102 that help reduce the contact resistance, materials that help reduce the contact resistance may also be selected on the material of the electrode group 500. In some embodiments, before laminating the first flexible substrate 100 and the second flexible substrate 200, the electrode group 500 may be surface-treated so that the material of the electrode group 500 contains tin or silver. For example, before laminating the first flexible substrate 100 and the second flexible substrate 200, a silver layer or a tin layer (not shown) is formed on the first electrode 500-1 and the second electrode 500-2. In some embodiments, the surface treatment method may include an electroless plating (electroplating-free) process on the electrode group 500. When the material of the electrode group 500 contains tin or silver, after lamination, a lower contact resistance value may be exhibited between the electrode group 500 and the pressure-sensitive material 102.

[0060] Please also refer to Figure 7A and Figure 7B , Figure 7A is a top view showing the pressure sensing device in one of the manufacturing stages according to some embodiments of the present invention, Figure 7B is a cross-sectional view showing the pressure sensing device along Figure 7A the section line A-A in. Next, in step S700, a protective layer 700 is formed on the second flexible substrate 200, thereby manufacturing the pressure sensing device 702.

[0061] In some embodiments, the protective layer 700 is disposed in the second opening O2 of the second flexible substrate 200 (see Figure 6A ) and is distributed between the first electrode 500-1 and the second electrode 500-2. In some further embodiments, the protective layer 700 fills the second opening O2 of the second flexible substrate 200 (see Figure 6A) such that the inner surfaces of the second openings O2 are all in direct contact with the protective layer 700, that is, the protective layer 700 is in direct contact with the first electrode 500-1 and the second electrode 500-2. The material of the protective layer 700 may include any suitable insulating material for insulation and protection. In some embodiments, the material of the protective layer 700 may be a solder mask layer.

[0062] When pressure is applied to the pressure sensing device 702 to cause deformation, it is equivalent to the third flexible substrate 600 (especially the second flexible substrate 200) being stretched, so that the pressure sensitive material 102 is also stretched and deformed accordingly. After the pressure sensitive material 102 is stretched, the spacing of the conductive materials (not shown) in the pressure sensitive material 102 will become larger accordingly, that is, the distribution of the conductive materials becomes thinner, resulting in a decrease in the conductive ability of the conductive materials, and then the electrical signal inside the pressure sensitive material 102 changes accordingly (for example, the resistance value of the pressure sensitive material 102 increases accordingly). Therefore, the magnitude of the external pressure applied can be obtained by measuring the change in the electrical signal of the pressure sensitive material 102 (for example, a linear relationship). In addition, the magnitude of the external pressure applied can be obtained by measuring the sum of the electrical signals of multiple pressure sensitive materials 102 to improve the measurement accuracy and sensitivity. Reducing the contact resistance can avoid deviation in the relationship between the electrical signal and the externally applied pressure, and improving the consistency of the electrode group 500 can help reduce the resistance tolerance. Therefore, reducing the contact resistance or improving the consistency of the electrode group 500 can enhance the sensing accuracy of the pressure sensing device.

[0063] In summary, the embodiments of the present invention provide a pressure sensing device and a manufacturing method thereof. By laminating a first flexible substrate provided with a pressure sensitive material and a second flexible substrate provided with an electrode group, the pressure sensitive material and the electrode group are electrically connected to each other and form a good contact resistance after lamination. In addition, the electrode group of the present invention is made from the same hole, thereby improving the consistency of the distance lengths of the individual electrodes in the electrode group, and improving the process yield by controlling the accuracy of the hole, thereby reducing the tolerance between different electrode groups. Thereby, the sensing accuracy of the pressure sensing device is improved.

[0064] The features of several embodiments of the present invention are outlined above to make it easier for those skilled in the art to understand the present invention. Any person skilled in the art should understand that this specification can easily be used as a basis for changes or designs of other structures or processes to achieve the same purpose and / or obtain the same advantages as the embodiments of the present invention. Any person skilled in the art can also understand that equivalent structures to the above do not depart from the spirit and scope of the present invention, and can be modified, substituted, and changed without departing from the spirit and scope of the present invention.

[0065]

Symbol Description

[0066] 100: First flexible substrate

[0067] 102: Pressure-sensitive material

[0068] 200: Second flexible substrate

[0069] 202: Circuit layer

[0070] 400: Conductive layer

[0071] 400-1: First part

[0072] 400-2: Second part

[0073] 400-3: Third part

[0074] 400-4: Fourth part

[0075] 500: Electrode group

[0076] 500-1: First electrode

[0077] 500-2: Second electrode

[0078] 510: Reference symmetry axis

[0079] 600: Third flexible substrate

[0080] 602: Adhesive material

[0081] 700: Protective layer

[0082] 702: Pressure sensing device

[0083] D-1: First distance

[0084] D-2: Second distance

[0085] O1: First opening

[0086] O2: Second opening

[0087] R: Cutting area

[0088] S1: First surface

[0089] S2: Second surface

[0090] S100: Step

[0091] S200: Step

[0092] S300: Step

[0093] S400: Step

[0094] S500: Step

[0095] S600: Step

[0096] S700: Step

[0097] A-A: Section line

Claims

1. A pressure sensing device, characterized in that, Comprising: A first flexible substrate; A pressure-sensitive material disposed on the first flexible substrate, wherein the pressure-sensitive material includes a plurality of conductive materials, and the plurality of conductive materials have silver, and the silver of the plurality of conductive materials has a tip structure; A second flexible substrate disposed on the pressure-sensitive material, comprising: A first surface facing the pressure-sensitive material; A second surface opposite to the first surface; and An opening extending to the first surface and the second surface; and An electrode group disposed in the opening and extending from the opening to the first surface and the second surface, wherein the electrode group is electrically connected to the pressure-sensitive material and includes: A first electrode covering a part of the inner surface of the opening, a part of the first surface and a part of the second surface; and A second electrode covering a part of the inner surface of the opening, a part of the first surface and a part of the second surface, wherein the second electrode and the first electrode are disposed opposite to each other and separated.

2. The pressure sensing device according to claim 1, wherein in a top view of the pressure sensing device viewed from the second surface, the first electrode and the second electrode are mirror-symmetric.

3. The pressure sensing device according to claim 1, wherein the first electrode has a first concave surface, and the second electrode has a second concave surface, and the first concave surface and the second concave surface face each other.

4. The pressure sensing device according to claim 1, wherein the pressure-sensitive material further includes: An elastic resin, wherein the plurality of conductive materials are distributed in the elastic resin.

5. The pressure sensing device according to claim 4, wherein the plurality of conductive materials include silver.

6. The pressure sensing device according to claim 5, wherein the plurality of conductive materials further include tin or bismuth.

7. The pressure sensing device according to claim 1, wherein the material of the electrode group includes tin or silver.

8. The pressure sensing device according to claim 1, wherein the electrode group disposed on the first surface of the second flexible substrate directly contacts the pressure-sensitive material.

9. The pressure sensing device according to claim 1, further comprising: A protective layer filling the opening of the second flexible substrate and distributed between the first electrode and the second electrode.

10. The pressure sensing device according to claim 9, wherein the electrode group disposed on the inner surface of the opening directly contacts the protective layer.

11. A method for manufacturing a pressure sensing device, characterized in that, Comprising: Providing a first flexible substrate; Disposing a pressure-sensitive material on the first flexible substrate; Providing a second flexible substrate including a first surface and a second surface, wherein the first surface is opposite to the second surface; Forming an opening in the second flexible substrate, wherein the opening extends to the first surface and the second surface; Forming a conductive layer on the inner surface of the opening and on the first surface, wherein in a top view viewed from the second surface, the conductive layer has a continuous edge; Removing a first part of the conductive layer and a second part opposite to the first part, so that the continuous edge of the conductive layer is disconnected to separate a first electrode and a second electrode; And Press the first flexible substrate and the second flexible substrate together such that the pressure-sensitive material electrically connects the first electrode and the second electrode, wherein the pressure-sensitive material is interposed between the first flexible substrate and the second flexible substrate.

12. The method of manufacturing a pressure sensing device according to claim 11, wherein after removing the first portion and the second portion, in the top view viewed from the second surface, the first electrode and the second electrode are mirror-symmetrical.

13. The method of manufacturing a pressure sensing device according to claim 11, wherein forming the conductive layer includes using an electroplating process.

14. The method of manufacturing a pressure sensing device according to claim 11, further comprising: Before pressing the first flexible substrate and the second flexible substrate together, forming a silver layer or a tin layer on the first electrode and the second electrode.

15. The method of manufacturing a pressure sensing device according to claim 11, wherein the pressing temperature for pressing the first flexible substrate and the second flexible substrate together is in the range between 180 degrees Celsius and 260 degrees Celsius.

16. The method of manufacturing a pressure sensing device according to claim 11, wherein pressing the first flexible substrate and the second flexible substrate together causes both the first electrode and the second electrode to directly contact the pressure-sensitive material.

17. The method of manufacturing a pressure sensing device according to claim 11, further comprising: Forming a protective layer on the second flexible substrate, wherein the protective layer is distributed between the first electrode and the second electrode.

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