TWI803033B - Pressure sensing device and method of fabricating thereof - Google Patents

Abstract

A pressure sensing device includes a flexible insulating substrate with a through hole, a pressure sensitive material in the through hole, a pair of electrodes and a cover layer. A width of the through hole is greater than 50 micrometers and an aspect ratio is greater than 2. A thickness of the pressure sensitive material is substantially same as a thickness of the flexible insulating substrate. The pair of electrodes includes a first electrode and a second electrode. The flexible insulating substrate is disposed between the first electrode and the second electrode and the pressure sensitive material electrically connects the first electrode and the second electrode. The cover layer is disposed on the flexible insulating substrate and the pressure sensitive material. With respect to the flexible insulating substrate, a difference of Young’s modulus between the cover layer and the flexible insulating substrate is less than 50%.

Description

Pressure sensing device and manufacturing method thereof

The disclosure relates to a pressure sensing device and a manufacturing method thereof.

The pressure sensing device can sense the pressure exerted by the user on it, and convert the deformation generated by the pressure into an electrical signal or other required forms of information output. The signal output by the force sensing device can trigger the feedback module, thereby providing users with an intuitive experience. For example, the touch panel can provide different vibration feedbacks according to different pressure levels of the user. If the pressure sensing device cannot provide accurate signals, the feedback module may not be able to provide accurate feedback, which will cause user perception errors or inconvenient operation.

When the pressure sensing device measures the pressure of a non-planar object to be measured, the pressure sensing device is obediently attached to the non-planar surface of the object to be measured, so that the pressure sensor has been deformed before the start of measurement, resulting in The sensing accuracy of the pressure sensing device is reduced. Therefore, how to prevent the sensing accuracy of the pressure sensing device from being affected by the surface of the object under test is a very important issue.

According to some embodiments of the present disclosure, a pressure sensing device includes a flexible insulating substrate having a through hole, a pressure sensitive material filling the through hole, a pair of electrodes, and a covering layer. The width of the through hole is greater than 50 microns and the aspect ratio of the through hole is greater than 2. The thickness of the pressure-sensitive material is substantially the same as that of the flexible insulating substrate. The electrode pair has a first electrode and a second electrode, wherein the flexible insulating substrate is located between the first electrode and the second electrode, and the first electrode and the second electrode are electrically connected to each other through the pressure-sensitive material. The covering layer is arranged on the soft insulating base material and the pressure-sensitive material, wherein the Young's modulus difference between the covering layer and the soft insulating base material is less than 50% of that of the soft insulating base material.

In some embodiments, the orthographic projection of the first electrode on the flexible insulating substrate and the orthographic projection of the second electrode on the flexible insulating substrate are separated from each other.

In some embodiments, the via is a trench extending from the first electrode to the second electrode.

In some embodiments, the first electrode and the second electrode are disposed on the same side of the flexible insulating substrate.

In some embodiments, the width of the trench is at least greater than 50 microns.

In some embodiments, the material of the electrode set includes silver.

According to some embodiments of the present disclosure, a method of manufacturing a pressure sensing device includes providing a flexible insulating substrate and forming vias in the flexible insulating substrate, wherein the vias have a width greater than 50 microns and an aspect ratio of the vias greater than 2. The method for manufacturing the pressure sensing device further includes filling the through hole with a pressure-sensitive material, wherein the thickness of the pressure-sensitive material is substantially the same as that of the flexible insulating substrate. The method for manufacturing the pressure sensing device further includes forming the first electrode and the second electrode on two of the plurality of ends of the pressure-sensitive material, so that the first electrode and the second electrode are electrically connected to each other through the pressure-sensitive material. sexual connection. The method for manufacturing the pressure sensing device also includes setting a soft covering layer on the soft insulating substrate and the pressure-sensitive material.

In some embodiments, forming the first electrode and the second electrode includes forming a silver layer directly contacting the pressure sensitive material.

In some embodiments, forming the via hole includes forming a groove with a pattern, and the pattern is distributed on the flexible insulating substrate, so that the pressure-sensitive material has the pattern after filling the groove with the pressure-sensitive material.

In some embodiments, forming the first electrode and the second electrode respectively at two of the several terminals of the pressure-sensitive material includes forming the first electrode and the second electrode respectively at two ends of the pattern.

In some embodiments, forming the first electrode and the second electrode respectively on two of the several terminals of the pressure-sensitive material includes forming the first electrode and the second electrode on the same side of the flexible insulating substrate.

Embodiments of the disclosure provide pressure sensing devices and methods of manufacturing the same. Filling the through hole in the flexible insulating substrate with the pressure sensitive material, and defining the size of the pressure sensitive material and the distance between the electrode pairs through the through hole to improve the sensing accuracy of the pressure sensing device.

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 be present. also exist. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. As used herein, "connected" may refer to physical and/or electrical connection. Furthermore, "electrically connected" or "coupled" may mean that other elements exist between two elements.

Additionally, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe one element's relationship to another element as shown in the figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in one of the figures is turned over, elements described as being on the "lower" side of other elements would then be oriented on "upper" sides of the other elements. Thus, the exemplary term "below" can encompass both "below" and "upper" orientations, depending on the particular orientation of the drawing. Similarly, if the device in one of the figures is turned over, elements described as "below" or "beneath" other elements would then be oriented "above" the other elements. Thus, the exemplary terms "below" or "under" can encompass both an orientation of above and below.

It is understandable that terms such as first, second and third are used herein to describe various elements, components, regions, layers and/or blocks. But these elements, components, regions, layers and/or blocks should not be limited by these terms. These terms are limited to identifying a single element, component, region, layer and/or block. Therefore, a first element, component, region, layer and/or block hereinafter may also be referred to as a second element, component, region, layer and/or block without departing from the original meaning of the present disclosure.

As used herein, "about," "approximately," or "substantially" includes stated values and averages within acceptable deviations from a particular value as determined by one of ordinary skill in the art, taking into account the measurements in question and the relative A specific amount of measurement-related error (ie, a limitation of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value.

Unless defined otherwise, 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 disclosure belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted as idealized or An overly formal sense, unless explicitly so defined herein.

The pressure sensing device can sense the pressure exerted on it, and convert the deformation generated by the pressure into an electrical signal or other required forms of information output. Therefore, the relationship (for example, linear relationship) between the magnitude of the pressure applied by the outside can be obtained through the change of the electrical signal of the pressure sensing device. However, when the pressure sensing device measures the pressure on a non-planar object, the pressure sensor has already moved in the horizontal direction before starting the measurement because the pressure sensing device is obedient to the non-planar surface of the object to be measured. Tensile strain produces electrical signals. This electrical signal will affect the interpretation of the actual pressure by the pressure sensing device, thereby reducing the sensing accuracy of the pressure sensing device. Embodiments of the present disclosure provide a pressure sensing device and a manufacturing method thereof, which reduce the impact of non-planar objects on pressure sensing accuracy by adopting strain sensitivity in the vertical direction.

Please refer to FIG. 1 and FIG. 2 at the same time. FIG. 1 is a top view of a pressure sensing device 100 according to the first embodiment of the disclosure, and FIG. 2 is a pressure sensor device 100 according to the first embodiment of the disclosure. A cross-sectional view of the sensing device 100 along the section line A-A in FIG. 1 . The pressure sensing device 100 includes a flexible insulating substrate 110 , a pressure-sensing layer 128 (including pressure-sensing materials 120 / 122 ), a circuit layer 140 , electrode pairs 130 / 132 and a cover layer 150 . FIG. 1 depicts an exemplary arrangement of the pressure sensitive layer 128 and the circuit layer 140 under the cover layer 150 with broken lines.

In the embodiment shown in Figure 1, the pressure-sensitive layer 128 has four pressure-sensitive materials 120/122/124/126 in total, and the shape of the pressure-sensitive materials 120/122/124/126 is circular in plan view, but this The disclosure case is not limited to this. The pressure-sensitive material 120/122/124/126 can adjust the quantity or shape of the pressure-sensitive material in the pressure-sensitive layer 128 according to product design or process requirements.

Since the pressure-sensitive material 120/122/124/126 has a conductive material (not shown), when an external power supply (not shown) is connected, the pressure-sensitive material 120/122/124/126 and the circuit layer 140 can be conductive. When pressure is applied to the pressure sensing device 100 to deform the pressure-sensitive material 120/122/124/126, the distance between the conductive materials (not shown) in the pressure-sensitive material 120/122/124/126 will change accordingly. , and then change the resistance of the conductive material, for example, the spacing of the conductive material (not shown) becomes shorter, so that the resistance of the conductive material becomes smaller. In this way, the resistance value and the electrical signal inside the pressure-sensitive material 120/122/124/126 can be changed correspondingly with the applied pressure, so by measuring the electrical signal of the pressure-sensitive material 120/122/124/126, the Get the pressure applied by the outside world.

The pressure-sensitive materials 120/122/124/126 in the pressure-sensing layer 128 can sense pressure individually or form a group of sensing units by connecting in series or in parallel. In some embodiments, the pressure-sensitive material 120/122/124/126 can be a group of pressure-sensitive units, wherein the electrical connection between the pressure-sensitive materials 120/122/124/126 can be like the circuit in Figure 1 Exemplary Configuration of Layer 140 . For example, the wiring 143 and the wiring 144 in the wiring layer 140 may be ground wires and are respectively connected to the pressure-sensitive material 126 and the pressure-sensitive material 124 . The wiring 145 can output the electrical signal between the pressure-sensitive material 120 and the pressure-sensitive material 124, the wiring 142 can output the electrical signal between the pressure-sensitive material 122 and the pressure-sensitive material 126, and the wiring 141 can output the electrical signal between the pressure-sensitive material 120 and the pressure-sensitive material 124. Electrical signals between pressure-sensitive materials 122 . In some embodiments, the sum of the electrical signals of a plurality of pressure-sensitive materials can be measured in series or in parallel to obtain the magnitude of the pressure applied by the outside, so as to increase the sensing area and improve the sensing accuracy.

In FIG. 2 , the pressure-sensitive material 120 / 122 is disposed in the flexible insulating substrate 110 . In some embodiments, the thickness of the pressure-sensitive material 120/122 is substantially the same as the thickness of the flexible insulating substrate 110, that is, the thickness of the pressure-sensitive material 120/122 and the thickness of the flexible insulating substrate 110 are both the thickness T1. The pressure sensitive material 120/122 has a width W1. In some embodiments, the width W1 of the pressure sensitive material 120/122 is greater than 50 microns. If the width W1 of the pressure-sensitive material 120 / 122 is less than 50 micrometers, the manufacturing process may be difficult.

When an external force exerts pressure on the pressure sensing device 100 along the z-axis direction, the pressure-sensitive material 120 / 122 can be deformed in the z-axis direction. However, when the pressure sensing device 100 is applied to a non-planar object, the pressure sensing device 100 may be conformed to the non-planar surface, which may cause the pressure sensor to be deformed in the xy-axis direction before starting the measurement, which may cause As a result, the sensing accuracy of the pressure sensing device is reduced. In order to reduce the influence of deformation in the xy-axis direction, in some embodiments, the aspect ratio of the pressure-sensitive material 120/122 (that is, the ratio of T1 to W1) can be greater than 2, so that the pressure-sensitive material 120/122 in the z-axis direction The deformation sensitivity is greater than that of the xy axis. If the aspect ratio of the pressure-sensitive material 120/122 is smaller than the aforementioned value, the sensing accuracy may decrease.

From another point of view, the flexible insulating substrate 110 has a first through hole O1 inside, and the first through hole O1 extends to opposite sides of the flexible insulating substrate 110, wherein the pressure sensitive material 120/122 fills the first through hole O1. The first through hole O1 can define the configuration of the pressure sensitive material 120 / 122 , so the size of the first through hole O1 is substantially equal to the size of the pressure sensitive material 120 / 122 . In some embodiments, the width W1 of the first through hole O1 is greater than 50 microns. In some embodiments, the aspect ratio of the first through hole O1 may be greater than 2.

The electrode pair 130/132 is electrically connected to the pressure-sensitive material 120/122 respectively, wherein the electrode pair 130 has an electrode 130A and an electrode 130B, and the electrode pair 132 has an electrode 132A and an electrode 132B. The electrode pair 130 and the electrode pair 132 have substantially the same structure, and the following description will only be described for the electrode pair 130 , and the description of the electrode pair 130 can be directly applied to the electrode pair 132 .

The flexible insulating substrate 110 is located between the electrode 130A and the electrode 130B of the electrode pair 130 . In detail, the flexible insulating substrate 110 separates the electrode 130A and the electrode 130B in the z-axis direction, so that the electrode 130A and the electrode 130B are disposed on different sides of the flexible insulating substrate 110 . The electrode 130A and the electrode 130B are electrically connected to each other through the pressure-sensitive material 120 . In some embodiments, the electrodes 130A and 130B directly contact the pressure-sensitive material 120 (eg, directly contact both ends of the pressure-sensitive material 120 in the z-axis direction). Besides, the electrode 130A and the electrode 130B are connected to the circuit layer 140 . It should be noted that the circuit layer 140 is simplified to clearly illustrate the concept of the present disclosure, and the circuit layer 140 only depicts a part of the circuit. In practical applications, the complete circuit layer 140 can be formed according to product design or process conditions.

FIG. 3 , FIG. 4 , FIG. 5 and FIG. 6 are cross-sectional views illustrating various stages of manufacturing the pressure sensing device 100 according to the first embodiment of the present disclosure. The reference sections of Fig. 3, Fig. 4, Fig. 5 and Fig. 6 are consistent with Fig. 2.

Unless otherwise specified, when the following embodiments illustrate or describe a series of operations or events, the description sequence of these operations or events should not be limited. For example, some operations or events may be undertaken in a different order than in the present disclosure, some operations or events may occur concurrently, some operations or events may not be required, and/or some operations or events may be repeated. Moreover, the actual manufacturing process may require additional operations before, during, or after each step to completely form the pressure sensing device. Therefore, this disclosure may briefly illustrate some of these additional operations.

Please refer to FIG. 3 , firstly, a flexible insulating substrate 110 is provided, which has a thickness T1. The circuit layer 140 is disposed on the flexible insulating substrate 110 . In some embodiments, the circuit layer 140 may be disposed on opposite sides of the flexible insulating substrate 110 (eg, different sides in the z-axis direction).

The material of the flexible insulating substrate 110 may include flexible polymer materials, such as polyimide (polyimide, PI), thermoplastic polyimide (thermoplastic polyimide, TPI), polyethylene terephthalate (polyethylene terephthalate, PET), polyethylene naphthalate (polythylene naphthalate, PEN), polyurethane (polyurethane, PU), thermoplastic polyurethane (thermoplastic polyurethane, TPU), other suitable materials, derivatives of the above, or the above materials any combination of . For example, the material of the flexible insulating substrate 110 may include thermoplastic polyimide (TPI).

The material of the circuit layer 140 may include metal, such as aluminum, gold, silver, copper, tin or other metals, or any combination of the above materials. In some embodiments, the wiring layer 140 may be a copper wiring.

Please refer to Figure 4. Next, a first through hole O1 is formed in the flexible insulating substrate 110 . The first through hole O1 penetrates through the flexible insulating substrate 110 , so that the flexible insulating substrate 110 has a hollow structure extending from both sides.

The forming method of the first through hole O1 may include laser drilling, mechanical drilling, other suitable techniques, or a combination of the above. The shape of the first through hole O1 in the xy-axis plane may be circular, elliptical, rectangular, rhombus, polygonal, or any suitable shape, but the present disclosure is not limited thereto. In some embodiments, the width W1 of the first through hole O1 is greater than 50 microns. If it is less than 50 microns, the difficulty of the subsequent process will increase, for example, it is difficult to fill the pressure-sensitive material into the first through hole O1 (for example, filling the pressure-sensitive material 120 / 122 , see FIG. 5 ). When the shape of the first through hole O1 in the xy-axis plane is circular, the width W1 can be the diameter of the first through hole O1 . In some embodiments, the aspect ratio of the first through hole O1 is greater than 2.

Please refer to Figure 5. Next, the pressure-sensitive material (such as the pressure-sensitive material 120 / 122 ) is filled in the first through hole O1 . The pressure-sensitive material 120/122 is filled in the first through hole O1, so the size and arrangement of the pressure-sensitive material 120/122 are defined by the first through hole O1. In some embodiments, the width W1 of the pressure-sensitive material 120 / 122 is substantially the same as the width W1 of the first through hole O1 . In some embodiments, the thickness T1 of the first through hole O1 is substantially the same as the thickness T1 of the flexible insulating substrate 110, and the thickness T1 of the pressure-sensitive material 120/122 is also substantially the same as the thickness T1 of the flexible insulating substrate 110. . The structure of the pressure-sensitive material 120/122 can be controlled by adjusting the structural accuracy of the first through hole O1, which helps to improve the consistency between the pressure-sensitive materials 120/122 and reduce the electrical signal tolerance of the pressure-sensitive material 120/122. difference.

The method of filling the first through hole O1 with the pressure-sensitive material 120 / 122 may include screen printing, gravure printing, jet printing and the like. In some embodiments, after filling, the exposed surface of the pressure-sensitive material 120 / 122 is flat and coplanar with the flexible insulating substrate 110 .

The material of the pressure-sensitive material 120/122 may include an elastic resin (not shown) and several conductive materials (not shown), wherein the elastic resin may serve as an insulating matrix, and the conductive material is distributed in the elastic resin to provide electrical conductivity. effect. The elastic resin of the pressure sensitive material 120/122/124/126 may include polydimethylsiloxane (polydimethylsiloxane, PDMS), thermoplastic polyurethane (thermoplastic polyurethane, TPU), polyester (polyester) resin, epoxy (epoxy) resin , silicone (silicon) resin, or other suitable materials, or any combination of the above materials. For example, the elastic resin of the pressure-sensitive layer 128 may include PDMS. In some embodiments, the elastic resin accounts for 35% to 55% by weight of the pressure-sensitive material 120 / 122 . In some embodiments, the elongation of the elastic resin ranges from 5% to 50%.

The conductive material of the pressure-sensitive material 120/122 may include metals, such as silver conductive powder, carbon conductive powder, conductive carbon nanotubes, nickel conductive powder, silver-coated aluminum conductive powder, silver-coated copper conductive powder, silver Nickel-coated 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 120/122 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 120/122 may include silver, such as silver conductive powder, silver-coated copper conductive powder, and the like. In some embodiments, the conductive material accounts for 45% to 65% by weight of the pressure sensitive material 120 / 122 . If the weight percentage of the conductive material in the pressure-sensitive material 120 / 122 is greater than the above-mentioned upper limit, it may make the process operation difficult (for example, the increase in viscosity makes it difficult to fill the first through hole O1 ). If the weight percentage of the conductive material in the pressure-sensitive material 120 / 122 is less than the aforementioned lower limit, the electrical performance of the pressure-sensitive material may be poor.

In some embodiments, the viscosity of the pressure-sensitive material 120 / 122 is between 8000 centipoise-second (cps) and 12000 cps before filling the first through hole O1 .

Please refer to Figure 6. Next, the electrode pair 130 and the electrode pair 132 are formed on the flexible insulating substrate 110 . The electrodes 130A and 130B of the electrode pair 130 respectively cover the surface of the pressure-sensitive material 120 exposed on the flexible insulating substrate 110 . The electrode 130A and the electrode 130B of the electrode pair 130 are electrically connected to each other through the pressure-sensitive material 120 . The material of the electrode pair 130 may include metal, such as aluminum, gold, silver, copper, tin or other metals, or any combination of the above materials. For example, the material of the electrode pair 130 may include silver. In some embodiments, the electrode 130A and the electrode 130B of the electrode pair 130 can be a silver layer, and directly contact the pressure-sensitive material 120 , thereby reducing the contact resistance between the electrode pair 130 and the pressure-sensitive material 120 . The electrode pair 132 has an electrode 132A and an electrode 132B respectively covering the surface of the pressure-sensitive material 122 exposed on the flexible insulating substrate 110. In addition, the electrode pair 132 is substantially the same as the aforementioned electrode pair 130, so it will not be described in detail. .

In some embodiments, after the electrode pair 130/132 is formed, the covering layer 150 is disposed on the flexible insulating substrate 110 and the pressure-sensitive material 120/122. The material of the cover layer 150 may include any suitable insulating material for insulation and protection. In some embodiments, the covering layer 150 may be flexible. In some further embodiments, the Young's modulus difference between the covering layer 150 and the flexible insulating substrate 110 is less than 50% relative to the flexible insulating substrate 110 .

Please refer to FIG. 7 , which is a top view of a pressure sensing device 200 according to a second embodiment of the disclosure. FIG. 7 shows the configuration of the pressure-sensitive layer 228 under the cover layer 250 with broken lines, wherein the cover layer 250 may correspond to the cover layer 150 in FIG. 1 , and the pressure-sensitive layer 228 may correspond to the pressure-sensitive layer in FIG. 1 128. In the embodiment shown in FIG. 7, the pressure-sensitive layer 228 has four pressure-sensitive materials 220/222/224/226 in total, and the shape of the pressure-sensitive materials 220/222/224/226 in the top view is a bent strip form, but this disclosure is not limited thereto. The pressure-sensitive material 220 / 222 / 224 / 226 can adjust the quantity of the pressure-sensitive material in the pressure-sensitive layer 228 or its strip shape according to product design or process requirements. In some embodiments, the pressure sensitive material 220/222/224/226 has a uniform topography.

Please refer to FIG. 8 , which is a partial configuration diagram of a pressure sensing device 200 according to a second embodiment of the present disclosure. FIG. 8 illustrates the arrangement among the electrode pairs 230/232/234/236, the circuit layer 240, and the pressure-sensitive material 220/222/224/226 on the flexible insulating substrate 210. Referring to FIG. It should be noted that the wiring layer 240 is simplified to clearly illustrate the concept of the present disclosure, and the wiring layer 240 only depicts a part of the wiring. In practical applications, the complete circuit layer 240 can be formed according to product design or process conditions.

The electrode pair 230 has an electrode 230A and an electrode 230B, which are respectively arranged at both ends of the pressure-sensitive material 220 on the xy-axis plane, and the electrode 230A and the electrode 230B are separated from each other. In other words, the pressure-sensitive material 220 extends from the electrode 230A to the electrode 230B. Likewise, the electrode pair 232 has an electrode 232A and an electrode 232B, which are respectively arranged at both ends of the pressure-sensitive material 222 on the xy-axis plane, and the electrode 232A and the electrode 232B are separated from each other. In other words, the pressure-sensitive material 222 extends from the electrode 232A to the electrode 232B.

Please refer to FIG. 9 , which is a cross-sectional view of the pressure sensing device 200 along the section line A-A in FIG. 8 according to the second embodiment of the present disclosure. The pressure sensing device 200 includes a flexible insulating substrate 210 , pressure sensitive materials 220 / 222 , a circuit layer 240 , electrode pairs 230 / 232 and a cover layer 250 . It should be noted that the covering layer 250 in FIG. 9 is omitted and not drawn in FIG. 8 .

The pressure sensing device 200 in FIG. 9 corresponds to the pressure sensing device 100 in FIG. 2 , the difference is that the pressure-sensitive material 220/222 is in the shape of a bent strip, so the first part 220A is shown in the cross-sectional view. and the second part 220B. In addition, the electrode 230A and the electrode 230B of the electrode pair 230 are arranged at both ends of the pressure-sensitive material 220, so in the cross-sectional view, the orthographic projection of the electrode 230A on the flexible insulating substrate 210 is the same as that of the electrode 230B on the flexible insulating substrate 210. Orthographic projections are separated from each other. The pressure sensitive material 222 and the electrode pair 232 have the structures as mentioned above. In the embodiment shown in FIG. 9 , the first portion 220A and the second portion 220B of the pressure-sensitive material 220 and the first portion 222A and the second portion 222B of the pressure-sensitive material 222 may be arranged alternately.

The electrode 230A and the electrode 230B connect the first part 220A and the second part 220B, respectively. In some embodiments, electrode 230A and electrode 230B directly contact first portion 220A and second portion 220B, respectively. The connection between the electrode pair 232 and the pressure-sensitive material 222 is the same as that between the electrode pair 230 and the pressure-sensitive material 220 . Therefore, in the embodiment shown in FIG. 9 , the electrode 230A, the electrode 232A, the electrode 230B, and the electrode 232B may also be alternately arranged with each other. In some embodiments, the electrode 230A and the electrode 230B are disposed on the same side of the flexible insulating substrate 210 .

In some embodiments, the thickness of the pressure-sensitive material 220/222 is substantially the same as that of the flexible insulating substrate 110, that is, the thickness of the pressure-sensitive material 220/222 and the thickness of the flexible insulating substrate 210 are both the thickness T1. The pressure sensitive material 220/222 has a width W1. In some embodiments, the width W1 of the pressure sensitive material 220/222 is greater than 50 microns. If the width W1 of the pressure-sensitive material 220 / 222 is less than 50 microns, it may increase the difficulty of the manufacturing process.

From another point of view, the flexible insulating substrate 210 has a second through hole O2 in it, and the second through hole O2 connects opposite sides of the flexible insulating substrate 210, wherein the pressure sensitive material 220/222 respectively fills the second through hole O2, so the size of the second through hole O2 is substantially equal to the size of the pressure-sensitive material 220/222. Therefore, the second through hole O2 can define the configuration of the pressure sensitive material 220 / 222 .

The second through hole O2 can be a groove with a pattern, and the pattern is distributed on the xy-axis plane of the flexible insulating substrate 210 (as shown in FIG. 8 ). For example, the trench extends from electrode 230A to electrode 230B (as shown in FIG. 8 ). After the pressure-sensitive material 220/222 respectively fills the groove, the pressure-sensitive material 220/222 may have a pattern similar to the groove.

FIG. 10 , FIG. 11 , FIG. 12 and FIG. 13 are cross-sectional views illustrating various stages of manufacturing the pressure sensing device 200 according to the second embodiment of the present disclosure. The reference sections of Fig. 10, Fig. 11, Fig. 12 and Fig. 13 are consistent with Fig. 9.

Unless otherwise specified, when the following embodiments illustrate or describe a series of operations or events, the description sequence of these operations or events should not be limited. For example, some operations or events may be undertaken in a different order than in the present disclosure, some operations or events may occur concurrently, some operations or events may not be required, and/or some operations or events may be repeated. Moreover, the actual manufacturing process may require additional operations before, during, or after each step to completely form the pressure sensing device. Therefore, this disclosure may briefly illustrate some of these additional operations.

Please refer to FIG. 10 , firstly, a flexible insulating substrate 210 is provided. The circuit layer 240 is disposed on the flexible insulating substrate 210 . In some embodiments, the wiring layer 240 may be disposed on opposite sides of the flexible insulating substrate 210 (eg, different sides in the z-axis direction). In some embodiments, the circuit layer 240 can be disposed on the same side of the flexible insulating substrate 210 .

Please refer to Figure 11. Next, a second through hole O2 is formed in the flexible insulating substrate 210 . The second through hole O2 penetrates through the flexible insulating substrate 110 , so that the flexible insulating substrate 210 has a hollow structure extending from both sides. In some embodiments, the second through hole O2 may be a groove with a pattern.

The forming method of the second through hole O2 may include laser drilling, mechanical drilling, other suitable techniques, or a combination of the above. The shape of the second through hole O2 in the top view may be a bent strip shape, but the present disclosure is not limited thereto. In some embodiments, the width W1 of the second through hole O2 is greater than 50 microns. If it is less than 50 microns, the difficulty of the subsequent process will increase, for example, it is difficult to fill the pressure-sensitive material into the second through hole O2 (for example, filling the pressure-sensitive material 220 / 222 , see FIG. 12 ).

Please refer to Figure 12. Next, the second through hole O2 is filled with a pressure-sensitive material (for example, the pressure-sensitive material 220 / 222 ). The pressure-sensitive material 220/222 is filled in the second through hole O2, so the size and arrangement of the pressure-sensitive material 220/222 are defined by the second through hole O2. In some embodiments, the width W1 of the pressure-sensitive material 220 / 222 is substantially the same as the width W1 of the second through hole O2 . In some embodiments, the thickness T1 of the second through hole O2 is substantially the same as the thickness T1 of the flexible insulating substrate 210, and the thickness T1 of the pressure-sensitive material 220/222 is also substantially the same as the thickness T1 of the flexible insulating substrate 110. . The pressure-sensitive material 220/222 can be controlled by adjusting the precision of the second through hole O2, which helps to improve the consistency between the pressure-sensitive material 220/222 and reduce the electrical signal tolerance value of the pressure-sensitive material 220/222.

The method of filling the pressure-sensitive material 220 / 222 into the second through hole O2 may include screen printing, gravure printing, jet printing and the like. In some embodiments, after filling, the exposed surface of the pressure-sensitive material 220 / 222 is flat and coplanar with the flexible insulating substrate 210 .

Please refer to Figure 13. Next, the electrode pair 230 and the electrode pair 232 are formed on the flexible insulating substrate 210 . The electrode 230A and the electrode 230B of the electrode pair 230 respectively cover the first portion 220A and the second portion 220B of the pressure-sensitive material 220 exposed on the surface of the flexible insulating substrate 110 . The electrode 230A and the electrode 230B are electrically connected to each other through the pressure-sensitive material 220 . After the pressure-sensitive material 220/222 is filled into the patterned second through hole O2 (such as a groove), the pressure-sensitive material 220/222 can have a similar pattern. In some embodiments, the electrode 230A and the electrode 230B can be respectively Formed on both ends of this pattern, as previously shown in Figure 8.

In some embodiments, after the electrode pair 230/232 is formed, the covering layer 250 is disposed on the flexible insulating substrate 210 and the pressure-sensitive material 220/222. Cover layer 250 is identical to cover layer 150 as previously described.

FIG. 14 is a cross-sectional view of a pressure sensing device 300 according to a third embodiment of the disclosure. The pressure sensing device 300 is similar to the pressure sensing device 200 of FIG. 9, the only difference being the configuration of the electrode pair 330/332. For example, the electrodes 330A and 330B of the electrode pair 330 are disposed on different sides of the flexible insulating substrate 210 , and the electrodes 332A and 332B of the electrode pair 332 are disposed on different sides of the flexible insulating substrate 210 .

FIG. 15 is a cross-sectional view of a pressure sensing device 400 according to a fourth embodiment of the disclosure. The pressure sensing device 400 includes a first flexible insulating substrate 410 , a second flexible insulating substrate 412 , pressure sensitive materials 420 / 422 , electrode pairs 430 / 432 and a covering layer 450 . The first flexible insulating substrate 410 , the second flexible insulating substrate 412 and the covering layer 450 are a three-layer structure, wherein the first flexible insulating substrate 410 is interposed between the second flexible insulating substrate 412 and the covering layer 450 . The pressure-sensitive material 420 / 422 is disposed in the first flexible insulating substrate 410 and extends to both sides of the first flexible insulating substrate 410 .

From another point of view, the first flexible insulating substrate 410 has a third through hole O3 inside, and the third through hole O3 extends to opposite sides of the first flexible insulating substrate 410, wherein the pressure-sensitive materials 420/422 are respectively filled. Fill the third via O3. The third through hole O3 can define the configuration of the pressure sensitive material 420/422, so the size of the third through hole O3 is substantially equal to the size of the pressure sensitive material 420/422. In some embodiments, the width W1 of the third through hole O3 is greater than 50 microns. In some embodiments, the aspect ratio of the third through hole O3 (ie, the ratio of the width W1 to the thickness T1 ) may be greater than 2.

The electrode pair 430/432 is electrically connected to the pressure-sensitive material 420/422. The electrode pair 430 includes an electrode 430A and an electrode 430B, which are respectively connected to two ends of the pressure-sensitive material 420 . The electrode pair 432 includes an electrode 432A and an electrode 432B, which are respectively connected to two ends of the pressure-sensitive material 422 . It should be noted that the electrode pair 430/432 of the pressure sensing device 400 can provide the function of a circuit layer, and the electrode pair 430/432 can be collectively referred to as a circuit layer.

FIG. 16 , FIG. 17 , FIG. 18 , FIG. 19 and FIG. 20 are cross-sectional views illustrating various stages of manufacturing a pressure sensing device 400 according to a fourth embodiment of the present disclosure. The reference sections of Fig. 16, Fig. 17, Fig. 18, Fig. 19 and Fig. 20 are consistent with Fig. 15.

Please refer to FIG. 16 , firstly, a first flexible insulating substrate 410 having a thickness T1 is provided. One of the electrodes of the electrode pair 430 (such as the electrode 430B) and one of the electrodes of the electrode pair 432 (such as the electrode 432B) are disposed on the first surface S1 of the first flexible insulating substrate 410 .

Please refer to Figure 17. Next, a third via hole O3 is formed in the first flexible insulating substrate 410 . The third through hole O3 extends from the second surface S2 of the first flexible insulating substrate 410 to the first surface S1 . The electrode 430B and the electrode 432B may be exposed in the third through hole O3.

In some embodiments, the width W1 of the third through hole O3 is greater than 50 microns. If it is less than 50 microns, the difficulty of the subsequent process will increase, for example, it is difficult to fill the pressure-sensitive material into the third through hole O3 (for example, filling the pressure-sensitive material 420 / 422 , see FIG. 18 ). The third through hole O3 has a depth T3. In some embodiments, the aspect ratio of the third through hole O3 is greater than 2.

Please refer to Figure 18. Next, the pressure-sensitive material (such as the pressure-sensitive material 420 / 422 ) is filled in the third through hole O3. The pressure-sensitive material 420/422 fills the third through hole O3, so the size and arrangement of the pressure-sensitive material 420/422 are defined by the third through hole O3. In some embodiments, the width W1 of the pressure-sensitive material 420 / 422 is substantially the same as the width W1 of the third through hole O3 . In some embodiments, the thickness T1 of the third through hole O3 is substantially the same as the thickness T1 of the flexible insulating substrate 110, and the thickness T1 of the pressure-sensitive material 420/422 is also substantially the same as the thickness T1 of the flexible insulating substrate 110. . The structure of the pressure-sensitive material 420/422 can be controlled by adjusting the structural accuracy of the third through hole O3, which helps to improve the consistency between the pressure-sensitive material 420/422 and reduce the electrical signal tolerance of the pressure-sensitive material 420/422. difference.

The method of filling the pressure-sensitive material 420 / 422 into the third through hole O3 may include screen printing, gravure printing, jet printing and the like. In some embodiments, after being filled, the exposed surface of the pressure-sensitive material 420 / 422 is flat and coplanar with the first flexible insulating substrate 410 .

Please refer to Figure 19. Next, a second flexible insulating substrate 412 is provided. The other electrode of the electrode pair 430 (such as the electrode 430A) and the other electrode of the electrode pair 432 (such as the electrode 432A) are disposed on the third surface S3 of the second flexible insulating substrate 412 . In some embodiments, the material of the second flexible insulating substrate 412 is the same as that of the first flexible insulating substrate 410 .

Please refer to Figure 20. Next, the first flexible insulating substrate 410 and the second flexible insulating substrate 412 are pressed together. Accordingly, the electrodes 430A and 432A disposed on the second flexible insulating substrate 412 can directly contact and electrically connect the pressure-sensitive material 420 and the pressure-sensitive material 422 respectively. In some embodiments, after lamination, the covering layer 450 is disposed on the first flexible insulating substrate 410 (for example, on the first surface S1 of the first flexible insulating substrate 410 ). The material of the cover layer 450 may include any suitable insulating material for insulation and protection. In some embodiments, the covering layer 450 may be flexible. In some further embodiments, the Young's modulus difference between the covering layer 450 and the flexible insulating substrate 110 is less than 50% relative to the flexible insulating substrate 110 .

Based on the above, embodiments of the present disclosure provide a pressure sensing device and a manufacturing method thereof. The pressure sensing device adopts strain sensitivity in the vertical direction (perpendicular to the flexible insulating substrate) to reduce the impact of non-planar objects on the pressure sensing accuracy. By filling the through holes in the flexible insulating substrate with the pressure-sensitive material, the horizontal dimension of the pressure-sensitive material can be effectively controlled, and the strain in the horizontal direction can be reduced. In the manufacturing process, the pressure-sensitive material is filled into the through hole of the flexible insulating substrate, the size of the pressure-sensitive material and the distance between the electrode pairs are defined through the through hole, and the process yield is improved through the precision control of the through hole. To help improve the sensing accuracy of the pressure sensing device.

The features of several embodiments of the present disclosure are briefly described above, so that those skilled in the art can understand the present disclosure more easily. Those skilled in the art should understand that this specification can be easily used as a basis for other structural or process changes or designs to achieve the same purpose and/or obtain the same advantages as the embodiments of the present disclosure. Anyone with ordinary knowledge in the technical field can also understand that the structure equivalent to the above does not depart from the spirit and protection scope of the disclosure, and can be modified, substituted and Revise.

100: Pressure sensing device

110: Soft insulating substrate

120: Pressure sensitive material

122: Pressure sensitive material

124: Pressure sensitive material

126: Pressure sensitive material

128: Pressure sensitive layer

130: electrode pair

130A: electrode

130B: electrode

132: electrode pair

132A: electrode

132B: electrode

140: line layer

141: Alignment

142: Alignment

143: Alignment

144: Alignment

145: Alignment

150: Overlay

200: pressure sensing device

210: flexible insulating substrate

220: Pressure sensitive material

220A: Part I

220B: Part II

222: Pressure sensitive material

222A: Part I

222B: Part Two

224: Pressure sensitive material

226: Pressure sensitive material

228: Pressure sensitive layer

230: electrode pair

230A: electrode

230B: electrode

232: electrode pair

232A: electrode

232B: electrode

234: electrode pair

236: electrode pair

240: line layer

250: Overlay

300: pressure sensing device

330: electrode pair

330A: electrode

330B: electrode

332: electrode pair

332A: electrode

332B: electrode

400: Pressure sensing device

410: the first flexible insulating substrate

412: the second flexible insulating substrate

420: Pressure Sensitive Materials

422: Pressure Sensitive Materials

430: electrode pair

430A: electrode

430B: electrode

432: electrode pair

432A: electrode

432B: electrode

450: Overlay

O1: the first through hole

O2: Second through hole

O3: the third through hole

S1: first surface

S2: second surface

S3: third surface

T1: Thickness

W1: width

x, y, z: reference coordinate axis

A-A: Sectional line

When reading the following implementation methods with accompanying drawings, the viewpoints of the disclosure can be clearly understood. It should be noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily expanded or reduced for clarity of discussion. Again, the same reference numerals denote the same elements. FIG. 1 is a top view of a pressure sensing device according to a first embodiment of the disclosure. FIG. 2 is a cross-sectional view of the pressure sensing device along line A-A in FIG. 1 according to the first embodiment of the disclosure. FIG. 3 , FIG. 4 , FIG. 5 and FIG. 6 are cross-sectional views illustrating various stages of manufacturing the pressure sensing device according to the first embodiment of the present disclosure. FIG. 7 is a top view of a pressure sensing device according to a second embodiment of the disclosure. FIG. 8 is a partial configuration diagram of a pressure sensing device according to a second embodiment of the disclosure. FIG. 9 is a cross-sectional view of the pressure sensing device along the line A-A in FIG. 8 according to the second embodiment of the disclosure. FIG. 10 , FIG. 11 , FIG. 12 and FIG. 13 are cross-sectional views illustrating various stages of manufacturing a pressure sensing device according to a second embodiment of the present disclosure. FIG. 14 is a cross-sectional view of a pressure sensing device according to a third embodiment of the disclosure. FIG. 15 is a cross-sectional view of a pressure sensing device according to a fourth embodiment of the disclosure. Fig. 16, Fig. 17, Fig. 18, Fig. 19 and Fig. 20 are cross-sectional views illustrating various stages of manufacturing a pressure sensing device according to a fourth embodiment of the present disclosure.

100: Pressure sensing device 110: Soft insulating substrate 120: Pressure sensitive material 122: Pressure sensitive material 130: electrode pair 130A: electrode 130B: electrode 132: electrode pair 132A: electrode 132B: electrode 140: line layer 150: Overlay O1: the first through hole T1: Thickness W1: width x, y, z: reference coordinate axes

Claims (9)

A pressure sensing device, comprising: a flexible insulating substrate, including a through hole, wherein the width of the through hole is greater than 50 microns and the aspect ratio of the through hole is greater than 2; a pressure-sensitive material, filling the through hole, the The thickness of the pressure-sensitive material is substantially the same as the thickness of the flexible insulating substrate; an electrode pair includes a first electrode and a second electrode, wherein the flexible insulating substrate is located between the first electrode and the second electrode , the first electrode and the second electrode are electrically connected to each other through the pressure-sensitive material, and the orthographic projection of the first electrode on the flexible insulating substrate and the orthographic projection of the second electrode on the flexible insulating substrate The projections are separated from each other; and a covering layer is disposed on the flexible insulating substrate and the pressure-sensitive material, wherein the Young's modulus difference between the covering layer and the flexible insulating substrate is relative to that of the flexible insulating substrate Young's modulus is less than 50%. The pressure sensing device as claimed in claim 1, wherein the through hole is a groove extending from the first electrode to the second electrode. The pressure sensing device according to claim 2, wherein the first electrode and the second electrode are disposed on the same side of the flexible insulating substrate. The pressure sensing device as claimed in claim 2, wherein the width of the groove is at least greater than 50 microns. The pressure sensing device as claimed in claim 1, wherein the material of the electrode group includes silver. A method of manufacturing a pressure sensing device, comprising: providing a flexible insulating substrate; forming a through hole in the flexible insulating substrate, wherein the width of the through hole is greater than 50 microns and the aspect ratio of the through hole is greater than 2; A pressure-sensitive material fills the through hole, wherein the thickness of the pressure-sensitive material is substantially the same as the thickness of the flexible insulating substrate; a first electrode and a second electrode are respectively formed at the plurality of terminals of the pressure-sensitive material on the same side of the flexible insulating substrate, so that the first electrode and the second electrode are electrically connected to each other through the pressure-sensitive material; a soft covering layer is arranged on the flexible insulating substrate material and the pressure-sensitive material. The method of manufacturing a pressure sensing device as claimed in claim 6, wherein forming the first electrode and the second electrode includes forming a silver layer directly contacting the pressure sensitive material. The method for manufacturing a pressure sensing device as described in claim 6, wherein forming the through hole includes forming a groove with a pattern and the pattern is distributed on the flexible insulating substrate so that when the pressure sensitive material is filled After the groove, the pressure-sensitive material has the pattern. The method for manufacturing a pressure sensing device according to claim 8, wherein forming the first electrode and the second electrode at two of the plurality of endpoints of the pressure-sensitive material includes forming the first electrode and the second electrode respectively. The second electrodes are respectively at two ends of the pattern.

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