Flexible array piezoelectric sensor and method of making same

Abstract

A flexible array piezoelectric sensor, a flexible substrate layer includes an array area and a lead-out area adjacent to the array area, the array area contains a plurality of sensing areas and interconnection areas, the interconnection areas are curves and have gaps between adjacent interconnection areas; a first electrode part of a lower electrode and a pattern of the sensing areas are overlapped, a first interconnection line and a part of the pattern of the lead-out area are overlapped; a piezoelectric array area of a flexible piezoelectric layer and the pattern of the sensing areas are overlapped, a piezoelectric lead-out area and a part of the pattern of the lead-out area are overlapped; a second electrode part of an upper electrode and the pattern of the sensing areas are overlapped, a second interconnection line and a part of the pattern of the lead-out area are overlapped; an insulating shielding layer and the pattern of the sensing areas are overlapped; an encapsulation layer and the pattern of the flexible substrate layer are overlapped. Thus, the array area of the sensor is hollow, and the interconnection areas are curves, so that the sensor has a curved conformal characteristic, and the air permeability of the sensor is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sensors, in particular to a flexible array piezoelectric sensor and a manufacturing method thereof. BACKGROUND

[0002] In recent years, thanks to the progress of flexible material science, the in-depth application of piezoelectric technology, and the continuous improvement of micro-nano processing and electronic technology, flexible piezoelectric sensor arrays have shown broad application prospects in the fields of biomedical, robot tactile perception, wearable devices, smart home, etc. For example, in the field of biomedicine, flexible piezoelectric sensor arrays can be used to monitor the physiological signals and motion state of the human body in real time, providing support for disease diagnosis and treatment. In the field of robot tactile perception, flexible piezoelectric sensor arrays can help robots perceive the external environment more accurately, improving the intelligence level and adaptability of robots.

[0003] Therefore, how to manufacture a flexible piezoelectric sensor that can be curved and conformal, while ensuring the air permeability of the sensor and having a relatively simple manufacturing process, has become a technical problem that needs to be solved in the industry. SUMMARY

[0004] The present application provides a flexible array piezoelectric sensor and a manufacturing method thereof, which solves the technical problem of how to manufacture a flexible piezoelectric sensor that can be curved and conformal, while ensuring the air permeability of the sensor and having a relatively simple manufacturing process.

[0005] According to a first aspect of the present application, a flexible array piezoelectric sensor is provided, comprising:

[0006] a flexible substrate layer, the flexible substrate layer comprising an array region and a lead-out region adjacent to the array region, the array region comprising a plurality of arrayed and mutually discrete sensing regions and interconnection regions connected between adjacent sensing regions, and having gaps between adjacent interconnection regions, the interconnection regions being curved parallel to the central axis of the surface of the flexible substrate layer;

[0007] a lower electrode located on the flexible substrate layer, the lower electrode comprising a plurality of arrayed and mutually discrete first electrode portions and first interconnection lines connected between adjacent first electrode portions in a first direction, the first electrode portions having a first projection pattern on the surface of the flexible substrate layer, the first projection pattern overlapping the sensing regions, the first interconnection lines having a second projection pattern on the surface of the flexible substrate layer, the second projection pattern partially overlapping the lead-out region;

[0008] a flexible piezoelectric layer on the lower electrode, the flexible piezoelectric layer comprising a piezoelectric array region and a piezoelectric lead-out region adjacent to the piezoelectric array region, the piezoelectric array region having a third projected pattern on the surface of the flexible substrate layer, the third projected pattern overlapping the sensing region, the piezoelectric lead-out region having a fourth projected pattern on the surface of the flexible substrate layer, the fourth projected pattern partially overlapping the lead-out region;

[0009] an upper electrode on the flexible piezoelectric layer, the upper electrode comprising a plurality of second electrode portions arranged in an array and separated from each other, and second interconnection lines connecting between adjacent second electrode portions in a second direction, the second electrode portions having a fifth projected pattern on the surface of the flexible substrate layer, the fifth projected pattern overlapping the sensing region, the second interconnection lines having a sixth projected pattern on the surface of the flexible substrate layer, the sixth projected pattern partially overlapping the lead-out region;

[0010] an insulating shielding layer on the upper electrode, the insulating shielding layer having a seventh projected pattern on the surface of the flexible substrate layer, the seventh projected pattern overlapping the sensing region;

[0011] a packaging layer on the shielding layer, and the eighth projected pattern of the packaging layer on the surface of the flexible substrate layer overlapping the flexible substrate layer.

[0012] Optionally, the first direction and the second direction are perpendicular to each other.

[0013] Optionally, the flexible substrate layer comprises a flexible base and a buffer layer on the flexible base.

[0014] Optionally, the upper electrode and the lower electrode are both composite electrodes of a high ductility metal material and indium tin oxide.

[0015] According to a second aspect of the present application, there is provided a method for manufacturing a flexible array piezoelectric sensor, comprising:

[0016] providing a first substrate;

[0017] forming a flexible substrate layer on the first substrate, the flexible substrate layer comprising an array region and a lead-out region adjacent to the array region;

[0018] forming a first patterned lower electrode on the flexible substrate layer, the lower electrode comprising a plurality of first electrode portions arranged in an array and separated from each other, and first interconnection lines connecting between adjacent first electrode portions in a first direction;

[0019] forming a flexible piezoelectric layer on the lower electrode, the flexible piezoelectric layer comprising a piezoelectric array region and a piezoelectric lead-out region adjacent to the piezoelectric array region;

[0020] forming a second patterned upper electrode on the flexible piezoelectric layer, the upper electrode comprising a plurality of second electrode portions arranged in an array and separated from each other, and a plurality of second interconnection lines connecting between adjacent second electrode portions along a second direction;

[0021] forming a third patterned insulating shielding layer on the upper electrode;

[0022] using the insulating shielding layer as a mask, etching the flexible piezoelectric layer and the flexible substrate layer until the surface of the first substrate, so that the array region comprises a plurality of sensing regions arranged in an array and separated from each other, and a plurality of interconnection regions connecting between adjacent sensing regions and having gaps between adjacent interconnection regions, the interconnection regions being curved parallel to the central axis of the surface of the flexible substrate layer; the first projection pattern of the first electrode portion on the surface of the flexible substrate layer overlaps with the sensing region, the second projection pattern of the first interconnection line on the surface of the flexible substrate layer partially overlaps with the lead-out region; the third projection pattern of the piezoelectric array region on the surface of the flexible substrate layer overlaps with the sensing region, the fourth projection pattern of the piezoelectric lead-out region on the surface of the flexible substrate layer partially overlaps with the lead-out region; the fifth projection pattern of the second electrode portion on the surface of the flexible substrate layer overlaps with the sensing region, and the sixth projection pattern of the second interconnection line on the surface of the flexible substrate layer partially overlaps with the lead-out region;

[0023] forming an encapsulation layer on the insulating shielding layer, the eighth projection pattern of the encapsulation layer on the surface of the flexible substrate layer overlapping with the flexible substrate layer;

[0024] removing the first substrate.

[0025] Optionally, forming a flexible substrate layer on the first substrate, comprising:

[0026] spinning a flexible solution on the substrate;

[0027] after spinning the flexible solution, performing annealing treatment on the flexible solution to obtain a flexible base;

[0028] performing solidification treatment on the flexible base;

[0029] depositing a buffer layer on the flexible base to form the flexible substrate layer.

[0030] Optionally, the pattern of the first patterned mask used to form the first patterned lower electrode is perpendicular to the pattern of the second patterned mask used to form the second patterned upper electrode.

[0031] Optionally, the insulating shielding layer comprises an insulating layer and a shielding layer, and forming a third patterned insulating shielding layer on the upper electrode comprises:

[0032] An insulating layer is deposited on the upper electrode;

[0033] A shielding layer is formed on the insulating layer by magnetron sputtering.

[0034] The shielding layer is formed by photolithography using a third patterned mask.

[0035] Optionally, using the insulating shielding layer as a mask, the flexible piezoelectric layer and the flexible substrate layer are etched down to the surface of the first substrate, including:

[0036] Using the third patterned shielding layer as a mask, the insulating layer, the flexible piezoelectric layer, and the flexible substrate layer are etched sequentially until the surface of the first substrate is reached.

[0037] Optionally, an encapsulation layer is formed on the insulating shielding layer, comprising:

[0038] Provide a second substrate;

[0039] A second flexible substrate layer is formed on the second substrate;

[0040] A second shielding layer is deposited on the second flexible substrate layer;

[0041] Using a fourth patterned mask, the second shielding layer is photolithographically formed on the second flexible substrate to create the fourth patterned second shielding layer.

[0042] Using the fourth patterned second shielding layer as a mask, the second flexible substrate layer is etched.

[0043] The encapsulation layer is obtained by removing the fourth patterned second shielding layer and the second substrate;

[0044] The encapsulation layer is attached to the surface of the insulating shielding layer.

[0045] Compared with the prior art, the technical solution of the embodiments of the present invention has the following beneficial effects:

[0046] In the flexible array piezoelectric sensor of the technical scheme, the flexible substrate layer comprises an array area and a lead-out area adjacent to the array area, the array area comprises a plurality of sensing areas and interconnection areas, the interconnection areas are curved and have gaps between adjacent interconnection areas; a first electrode part of the lower electrode and the sensing areas are overlapped in pattern, and a first interconnection line is overlapped with part of the pattern of the lead-out area; a piezoelectric array area of the flexible piezoelectric layer is overlapped with the pattern of the sensing areas, and a piezoelectric lead-out area is overlapped with part of the pattern of the lead-out area; a second electrode part of the upper electrode is overlapped with the pattern of the sensing areas, and a second interconnection line is overlapped with part of the pattern of the lead-out area; an insulating shielding layer is overlapped with the pattern of the sensing areas; and an encapsulation layer is overlapped with the pattern of the flexible substrate layer. Thus, the array area of the sensor is hollowed out, and the interconnection areas are curved, so that the sensor has the characteristics of curved surface conformation, and the air permeability of the sensor is ensured.

[0047] In the manufacturing method of the flexible array piezoelectric sensor of the technical scheme, a flexible substrate layer is formed on a first substrate, a first patterned lower electrode is formed on the flexible substrate layer, a flexible piezoelectric layer is formed on the lower electrode, a second patterned upper electrode is formed on the flexible piezoelectric layer, and a third patterned insulating shielding layer is formed on the upper electrode. The flexible piezoelectric layer and the flexible substrate layer are etched with the insulating shielding layer as a mask until the surface of the substrate, so that the array area of the sensor is hollowed out by twice etching, the manufacturing process is relatively simple, and an encapsulation layer is formed on the shielding layer, the eighth projection pattern of the encapsulation layer on the flexible substrate layer is the same as the flexible substrate layer, so that the layers of the flexible array piezoelectric sensor are curved surface conformable, and the air permeability of the sensor is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0048] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0049] Figures 1-21 is the device structure schematic diagram formed by the main steps of manufacturing the flexible array piezoelectric sensor provided by an embodiment of the present application;

[0050] Figure 22 is the split diagram of each layer of the flexible array piezoelectric sensor provided by an embodiment of the present application;

[0051] Figure 23 is the process flow schematic diagram of the present application;

[0052] Figure 24 is the first patterned mask provided by the present application;

[0053] Figure 25 is a second patterned mask plate of the present application;

[0054] Figure 26 is a third patterned mask plate of the present application;

[0055] Figure 27 is a fourth patterned mask plate of the present application.

[0056] BRIEF DESCRIPTION OF DRAWINGS

[0057] 10 - first substrate;

[0058] 20 - flexible substrate layer;

[0059] 201 - flexible base;

[0060] 202 - buffer layer;

[0061] 30 - lower electrode;

[0062] 301 - first electrode portion;

[0063] 302 - first interconnection line;

[0064] 31 - first patterned mask layer;

[0065] 40 - flexible piezoelectric layer;

[0066] 50 - upper electrode;

[0067] 501 - second electrode portion;

[0068] 502 - second interconnection line;

[0069] 51 - second patterned mask layer;

[0070] 601 - insulating layer;

[0071] 602 - shielding layer;

[0072] 70 - second substrate;

[0073] 80 - second flexible substrate layer;

[0074] 801 - encapsulation layer;

[0075] 90 - second shielding layer. DETAILED DESCRIPTION

[0076] As described in the background section, how to manufacture a flexible piezoelectric sensor that can be curved conformable, while ensuring the air permeability of the sensor and the production process is relatively simple, has become a technical problem that the industry needs to solve at present. The following will be described in detail in conjunction with the drawings.

[0077] Before the present application, the applicant has made a full research on the device structure and manufacturing method of the current flexible piezoelectric sensor,

[0078] The existing flexible piezoelectric sensor is generally a sandwich type sensor, and the device structure is generally substrate layer - lower electrode - piezoelectric layer - upper electrode - packaging layer. The steps are to first prepare the substrate layer, then deposit the electrode material on the substrate layer by magnetron sputtering or printing, prepare the piezoelectric layer on the lower electrode by spin coating or blade coating, then deposit the upper electrode on the piezoelectric layer by the same electrode deposition method, and finally prepare the packaging layer on the upper electrode by pasting or spin coating. However, the substrate layer and the packaging layer of the existing flexible piezoelectric sensor are generally flexible films, and when the sensor is attached to the human body, it will cause the phenomenon of not breathable, which affects the comfort and use effect, and it is difficult to fit the curved surface. At the same time, the interconnection part between the pixel points of the existing scheme is mostly straight wire connection, but if the sensor wants to be attached to the non-planar surface, the attachment may not be good.

[0079] In order to solve the above problems, the embodiment of the present application provides a manufacturing method of a flexible array piezoelectric sensor, comprising:

[0080] providing a first substrate;

[0081] forming a flexible substrate layer on the first substrate, the flexible substrate layer comprising an array area and a lead-out area adjacent to the array area;

[0082] forming a first patterned lower electrode on the flexible substrate layer, the lower electrode comprising a plurality of first electrode parts arranged in an array and separated from each other, and a first interconnection line connected between adjacent first electrode parts in a first direction;

[0083] forming a flexible piezoelectric layer on the lower electrode, the flexible piezoelectric layer comprising a piezoelectric array area and a piezoelectric lead-out area adjacent to the piezoelectric array area;

[0084] forming a second patterned upper electrode on the flexible piezoelectric layer, the upper electrode comprising a plurality of second electrode parts arranged in an array and separated from each other, and a second interconnection line connected between adjacent second electrode parts in a second direction;

[0085] forming a third patterned insulating shielding layer on the upper electrode;

[0086] Etching the flexible piezoelectric layer and the flexible substrate layer with the insulating shielding layer as a mask until the surface of the first substrate, so that the array area includes a plurality of arrayed and separated sensing areas and interconnection areas connected between adjacent sensing areas, and gaps between adjacent interconnection areas, and the interconnection areas are curved parallel to the central axis of the surface of the flexible substrate layer; the first electrode part has a first projection pattern on the surface of the flexible substrate layer which overlaps with the sensing area, the first interconnection line has a second projection pattern on the surface of the flexible substrate layer which partially overlaps with the lead-out area; the piezoelectric array area has a third projection pattern on the surface of the flexible substrate layer which overlaps with the sensing area, the piezoelectric lead-out area has a fourth projection pattern on the surface of the flexible substrate layer which partially overlaps with the lead-out area; the second electrode part has a fifth projection pattern on the surface of the flexible substrate layer which overlaps with the sensing area, and the second interconnection line has a sixth projection pattern on the surface of the flexible substrate layer which partially overlaps with the lead-out area;

[0087] Forming an encapsulation layer on the insulating shielding layer, and the eighth projection pattern of the encapsulation layer on the surface of the flexible substrate layer overlaps with the flexible substrate layer;

[0088] Removing the first substrate.

[0089] Therefore, the manufacturing method provided by the application forms a flexible substrate layer on a first substrate, forms a first patterned lower electrode on the flexible substrate layer, forms a flexible piezoelectric layer on the lower electrode, forms a second patterned upper electrode on the flexible piezoelectric layer, forms a third patterned insulating shielding layer on the upper electrode, and etches the piezoelectric layer and the flexible substrate layer with the insulating shielding layer as a mask until the surface of the substrate, so that the corresponding layers of the sensor array area are hollowed out through twice etching, the manufacturing process is relatively simple, and an encapsulation layer is formed on the shielding layer subsequently, the eighth projection pattern of the encapsulation layer on the surface of the flexible substrate layer is the same as the flexible substrate layer, so that the flexible array piezoelectric sensor is ensured to have a curved surface and the sensor is ensured to be breathable.

[0090] As a specific embodiment, refer to Figure 23 , a flow chart of the manufacturing method of the flexible array piezoelectric sensor provided by the embodiment of the application is shown, which includes:

[0091] S11: providing a first substrate;

[0092] S12: forming a flexible substrate layer on the first substrate, and the flexible substrate layer includes an array area and a lead-out area adjacent to the array area;

[0093] S13: forming a first patterned lower electrode on the flexible substrate layer, the lower electrode comprising a plurality of first electrode portions arranged in an array and separated from each other, and a first interconnection line connecting between adjacent first electrode portions in a first direction;

[0094] S14: forming a flexible piezoelectric layer on the lower electrode, the flexible piezoelectric layer comprising a piezoelectric array region and a piezoelectric lead-out region adjacent to the piezoelectric array region;

[0095] S15: forming a second patterned upper electrode on the flexible piezoelectric layer, the upper electrode comprising a plurality of second electrode portions arranged in an array and separated from each other, and a second interconnection line connecting between adjacent second electrode portions in a second direction;

[0096] S16: forming a third patterned insulating shielding layer on the upper electrode;

[0097] S17: etching the flexible piezoelectric layer and the flexible substrate layer with the insulating shielding layer as a mask until the surface of the first substrate, so that the array region comprises a plurality of sensing regions arranged in an array and separated from each other, and an interconnection region connecting between adjacent sensing regions, and the interconnection region is curved parallel to the central axis of the surface of the flexible substrate layer; the first electrode portions have a first projected pattern on the surface of the flexible substrate layer which overlaps with the sensing regions, the first interconnection line has a second projected pattern on the surface of the flexible substrate layer which partially overlaps with the lead-out region; the piezoelectric array region has a third projected pattern on the surface of the flexible substrate layer which overlaps with the sensing regions, the piezoelectric lead-out region has a fourth projected pattern on the surface of the flexible substrate layer which partially overlaps with the lead-out region; the second electrode portions have a fifth projected pattern on the surface of the flexible substrate layer which overlaps with the sensing regions, and the second interconnection line has a sixth projected pattern on the surface of the flexible substrate layer which partially overlaps with the lead-out region;

[0098] S18: forming an encapsulation layer on the insulating shielding layer, the encapsulation layer having an eighth projected pattern on the surface of the flexible substrate layer which overlaps with the flexible substrate layer;

[0099] S19: removing the first substrate.

[0100] The following will be described with reference to the accompanying drawings, Figures 1-21 The following will be described with reference to the accompanying drawings, Figures 1-21 is a structural schematic diagram in the manufacturing process of the flexible array piezoelectric sensor of the embodiment of the present application.

[0101] Please refer to Figure 1 , a first substrate 10 is provided.

[0102] As an example, the first substrate 10 can be a glass substrate, of course, the present application is not limited thereto, and can also be a metal substrate, a plastic substrate, etc., and a person skilled in the art can select a suitable substrate material as needed.

[0103] As an example, the first substrate 10 can be a glass substrate, in actual work, before the subsequent process is prepared on the first substrate 10, the glass substrate also needs to be put into the cleaning machine for water washing and blowing away the water droplets.

[0104] In this embodiment, a flexible substrate layer 20 is subsequently formed on the first substrate 10, the flexible substrate layer 20 includes an array area and a lead-out area adjacent to the array area, and the process of forming the flexible substrate layer 20 is described in detail in the following embodiments. Figures 2-3 .

[0105] Please refer to Figure 2 , spin-coating a flexible solution on the first substrate 10; after spin-coating the flexible solution, annealing treatment is performed on the flexible solution to obtain a flexible substrate 201; and curing treatment is performed on the flexible substrate 201.

[0106] In a specific embodiment, the flexible solution is a polyimide solution, in which case, the annealing treatment performed on the flexible solution includes:

[0107] sequentially performing low-temperature annealing treatment and high-temperature annealing treatment on the polyimide solution to form a polyimide substrate;

[0108] In a specific embodiment, the curing treatment performed on the flexible substrate 201 includes:

[0109] UV curing treatment is performed on the polyimide substrate.

[0110] In other embodiments, the flexible solution can also be a polyurethane (PU) solution, a polydimethylsiloxane (PDMS) solution, etc., and the present application is not limited thereto.

[0111] Please refer to Figure 3 , a buffer layer 202 is deposited on the flexible substrate 201 to form the flexible substrate layer 20.

[0112] In an embodiment, the buffer layer 202 is deposited on the flexible substrate 201 by a chemical vapor deposition process. As an example, the buffer layer 202 can be composed of silicon nitride and silicon dioxide, or can be replaced by silicon nitride or silicon dioxide alone, and of course, a person skilled in the art can select a suitable buffer layer 202 material according to the specific process requirements and conditions.

[0113] In this embodiment, a first patterned lower electrode is formed on the flexible substrate layer 20, which includes a plurality of first electrode portions arranged in an array and separated from each other, and first interconnection lines connecting between adjacent first electrode portions in a first direction. The process of forming the lower electrode 30 is described in detail in the following. Figures 4-6 .

[0114] As shown in Figure 4 , the lower electrode 30 is deposited on the flexible substrate layer 20.

[0115] In one specific embodiment, the lower electrode 30 is deposited on the flexible substrate layer 20 by a magnetron sputtering process. For example, the lower electrode 30 is a composite electrode of aluminum and indium tin oxide. In this case, the method of depositing the lower electrode 30 on the flexible substrate layer 20 includes:

[0116] depositing an aluminum electrode layer on the flexible substrate layer 20 by a magnetron sputtering process;

[0117] depositing an indium tin oxide electrode layer on the aluminum electrode layer by a magnetron sputtering process.

[0118] For example, the thickness of the aluminum electrode layer can be 150 nm, and the thickness of the indium tin oxide electrode layer can be 100 nm.

[0119] Of course, the present application is not limited to the electrode material of the lower electrode 30. For example, the aluminum electrode layer can be replaced by other high ductility metal materials, such as gold, silver, titanium, etc. This is because, after the flexible piezoelectric layer 40 is formed, the surface of the flexible piezoelectric layer 40 is not necessarily flat, and these high ductility metal materials can fill the pits and depressions on the surface of the flexible piezoelectric layer 40, so that the upper electrode 50 can be better attached to the flexible piezoelectric layer 40.

[0120] As shown in Figure 5 , a first patterned mask layer 31 is formed on the lower electrode 30 based on a first patterned mask plate.

[0121] In one specific embodiment, the method of forming the first patterned mask layer 31 includes:

[0122] coating a photoresist on the exposed lower electrode 30, exposing and developing the photoresist to form a patterned photoresist.

[0123] In one specific embodiment, the first patterned mask plate can be as shown in Figure 24 .

[0124] In a preferred embodiment, when designing the mask layer, if the array region includes multiple arrays, the electrode patterns of each array are oriented as evenly as possible to the four sides of the substrate, facilitating subsequent doctor blading and spin coating photoresist processes.

[0125] Please refer to Figure 6 The lower electrode 30 is etched by taking the first patterned mask layer 31 as a mask to form a first patterned lower electrode 30, the lower electrode 30 including a plurality of first electrode parts 301 arranged in an array and separated from each other, and a first interconnection line 302 connected between adjacent first electrode parts 301 in a first direction; and the first patterned mask layer 31 is removed.

[0126] In a specific embodiment, the lower electrode 30 is etched by a wet etching process.

[0127] In a specific embodiment, when the material of the mask layer is photoresist and the material of the flexible piezoelectric layer in the subsequent process is polyvinylidene fluoride (PVDF), a photoresist stripping solution should be used for the photoresist removal process, and an acetone solution cannot be used.

[0128] Please refer to Figure 7 A flexible piezoelectric layer 40 is formed on the lower electrode 30, the flexible piezoelectric layer 40 including a piezoelectric array region and a piezoelectric lead-out region adjacent to the piezoelectric array region.

[0129] In a specific embodiment, the flexible piezoelectric layer 40 formed on the lower electrode 30 includes:

[0130] The piezoelectric material is doctor bladed on the lower electrode 30;

[0131] The piezoelectric material is polarized to form the flexible piezoelectric layer 40.

[0132] In a specific embodiment, the polarization direction of the piezoelectric material is the Z-axis direction, of course, the present application is not limited thereto, and those skilled in the art can select a suitable polarization direction according to application requirements.

[0133] As an example, the piezoelectric material can be polyvinylidene fluoride (PVDF), of course, it can also be polyvinylidene fluoride-trifluoroethylene copolymer (P(VDF-TrFE)) and the like, and the present application is not limited thereto.

[0134] In this embodiment, a second patterned upper electrode is subsequently formed on the flexible piezoelectric layer, the upper electrode including a plurality of second electrode parts arranged in an array and separated from each other, and a second interconnection line connected between adjacent second electrode parts in a second direction; the process of forming the lower electrode is described with reference to FIGS. 8 to Figure 11 .

[0135] Referring to Figure 8 The upper electrode 50 is deposited on the flexible piezoelectric layer 40.

[0136] In one embodiment, the upper electrode 50 is deposited on the flexible piezoelectric layer 40 by a magnetron sputtering process, for example, the upper electrode 50 is a composite electrode of the same high ductility metal material as the lower electrode and indium tin oxide.

[0137] Referring to Figure 9 A second patterned mask layer 51 is formed on the flexible piezoelectric layer 40 based on a second patterned mask plate.

[0138] The method of forming the second patterned mask layer 51 is similar to the method of forming the first patterned mask layer 31, which will not be described here. In actual implementation, unevenness may occur when the photoresist is spin-coated on the flexible piezoelectric layer 40, which can be solved by manual photoresist supplement.

[0139] In one embodiment, the pattern of the second patterned mask plate is as shown in Figure 25 .

[0140] In a preferred embodiment, the pattern of the first patterned mask plate for forming the first patterned lower electrode 30 is perpendicular to the pattern of the second patterned mask plate.

[0141] Referring to Figure 10 The upper electrode 50 is etched to form a second patterned upper electrode 50 using the second patterned mask layer 51 as a mask, the second patterned upper electrode 50 includes a plurality of second electrode portions 501 arranged in an array and separated from each other, and a second interconnection line 502 connected between adjacent second electrode portions 501 in a second direction; and the second patterned mask layer 51 is removed.

[0142] Referring to Figure 11 The second patterned mask layer is removed.

[0143] In this embodiment, a third patterned insulating shielding layer is subsequently formed on the upper electrode, and the process of forming the insulating shielding layer is described with reference to Figures 11-13 .

[0144] In one embodiment, the insulating shielding layer includes an insulating layer 601 and a shielding layer 602, in which case, referring to Figure 11 , the insulating layer 601 is deposited on the upper electrode 50.

[0145] In one embodiment, the insulating layer 601 can be deposited on the patterned upper electrode 50 by a chemical vapor deposition process.

[0146] As an example, the material of the insulation layer 601 can be a silicon dioxide insulation layer, a silicon nitride insulation layer, etc. In the present embodiment, a 200 nm silicon dioxide insulation layer is deposited on the patterned upper electrode 50 by a chemical vapor deposition process. If the material of the flexible piezoelectric layer 40 is polyvinylidene fluoride (PVDF), the temperature of the chemical vapor deposition process can be selected as 80°C to ensure that the PVDF material can work normally.

[0147] Referring to FIG. 6B, a shielding layer 602 is formed on the insulation layer 601 by a magnetron sputtering process. Figure 12

[0148] In a specific embodiment, the material of the shielding layer 602 is indium tin oxide. Of course, a material with good shielding performance, such as aluminum, etc., can also be selected. As an example, when the material of the shielding layer 602 is indium tin oxide, the thickness of the shielding layer 602 can be 100 nm.

[0149] Referring to FIG. 6C, the shielding layer 602 is patterned by photolithography using a third patterned mask. Figure 13

[0150] In a specific example, the method of patterning the shielding layer 602 to form the third patterned shielding layer 602 is similar to the method of forming the first patterned mask layer 31.

[0151] In a specific embodiment, the third patterned mask can be as shown in FIG. 6D. Figure 26

[0152] In the present embodiment, the flexible piezoelectric layer 40 and the flexible substrate layer 20 are etched using the insulation shielding layer as a mask until the surface of the first substrate 10, so that the array region includes a plurality of arrayed and mutually separated sensing regions and interconnection regions connected between adjacent sensing regions, and gaps are provided between adjacent interconnection regions. The interconnection regions are curved parallel to the central axis of the surface of the flexible substrate layer 20. The first electrode portion 301 has a first projection pattern on the surface of the flexible substrate layer 20 that overlaps the sensing region. The first interconnection line 302 has a second projection pattern on the surface of the flexible substrate layer 20 that partially overlaps the lead-out region. The piezoelectric array region has a third projection pattern on the surface of the flexible substrate layer 20 that overlaps the sensing region. The piezoelectric lead-out region has a fourth projection pattern on the surface of the flexible substrate layer 20 that partially overlaps the lead-out region. The second electrode portion 501 has a fifth projection pattern on the surface of the flexible substrate layer 20 that overlaps the sensing region. The second interconnection line 502 has a sixth projection pattern on the surface of the flexible substrate layer 20 that partially overlaps the lead-out region. ​​​

[0153] Etching the flexible piezoelectric layer 40 and the flexible substrate layer 20 with the insulating shielding layer as a mask, until the surface of the first substrate, please refer to Figure 14 .

[0154] Please refer to Figure 14 Etching the flexible piezoelectric layer 40 and the flexible substrate layer 20 with the insulating shielding layer as a mask, until the surface of the first substrate, please refer to

[0155] In a specific embodiment, the insulating layer 601, the flexible piezoelectric layer 40 and the flexible substrate layer 20 are etched in sequence by dry etching process, until the surface of the first substrate 10.

[0156] In actual implementation, the gases used for etching the flexible piezoelectric layer 40 and the flexible substrate layer 20 are different, for example, the flexible piezoelectric layer 40 can be etched by carbon tetrafluoride gas (CF4), and the flexible substrate layer 20 can be etched by sulfur hexafluoride gas (SF6), of course, the present application is not limited thereto, and those skilled in the art can select appropriate etching gas according to the materials of the flexible piezoelectric layer 40 and the flexible substrate layer 20.

[0157] It can be seen that the present application ensures that each layer corresponding to the sensor array area is hollowed out by twice etching, and the interconnection area is a curve, so that the sensor has the characteristics of curved surface conformal, and the air permeability of the sensor is ensured.

[0158] In this embodiment, a packaging layer is subsequently formed on the insulating shielding layer, and the eighth projection of the packaging layer on the surface of the flexible substrate layer overlaps with the flexible substrate layer. The process of forming a packaging layer on the shielding layer is described in Figures 15-20 .

[0159] Referring to Figure 15 , a second substrate 70 is provided.

[0160] As an example, the second substrate 70 can also be a glass substrate, of course, the present application is not limited thereto, and of course, it can also be a metal substrate, a plastic substrate, etc., and those skilled in the art can select a suitable substrate material as needed.

[0161] Referring to Figure 16 , a second flexible substrate layer 80 is formed on the second substrate 70.

[0162] In a specific embodiment, the method of forming the second flexible substrate layer 80 on the second substrate 70 is similar to the method of forming the first flexible substrate layer 20, which will not be repeated here.

[0163] As an example, the material of the second flexible substrate layer 80 is also polyimide.

[0164] Referring to Figure 17 , a second shielding layer 90 is deposited on the second flexible substrate layer 80.

[0165] In a specific embodiment, the second shielding layer 90 is deposited on the flexible substrate layer 20 by a magnetron sputtering process.

[0166] As an example, the material of the second shielding layer 90 can also be indium tin oxide. In actual operation, the thickness of the second shielding layer 90 can also be 100 nm.

[0167] Referring to Figure 18 , the second shielding layer 90 is photoetched using a fourth patterned mask, and a fourth patterned second shielding layer 90 is formed on the second flexible substrate layer 80; the second flexible substrate layer 80 is etched with the fourth patterned second shielding layer 90 as a mask.

[0168] In a specific embodiment, the fourth patterned mask can be as shown in Figure 27 .

[0169] Referring to Figure 19 , the fourth patterned second shielding layer 90 and the second substrate 70 are removed to obtain the packaging layer 801.

[0170] In a specific embodiment, the fourth patterned second shielding layer 90 is removed by a wet etching process;

[0171] The second flexible substrate layer 80 and the second substrate 70 are soaked in deionized water to remove the mold to obtain the packaging layer 801.

[0172] In the embodiment, a packaging layer is subsequently formed on the insulating shielding layer, and the eighth projection pattern of the packaging layer on the surface of the flexible substrate layer overlaps with the flexible substrate layer.

[0173] Subsequently, the packaging layer 801 is bonded to the surface of the shielding layer 602. Figure 20 The packaging layer 801 is bonded to the surface of the shielding layer 602.

[0174] The packaging layer 801 is bonded to the surface of the shielding layer 602. Figure 20 The first substrate 10 is removed. After the step is completed, the flexible array piezoelectric sensor of the present application is obtained.

[0175] The packaging layer 801 is bonded to the surface of the shielding layer 602. Figure 21 The first substrate 10 is removed. After the step is completed, the flexible array piezoelectric sensor of the present application is obtained.

[0176] The packaging layer 801 is bonded to the surface of the shielding layer 602. Figure 22 , Figure 22 The packaging layer 801 is bonded to the surface of the shielding layer 602.

[0177] In the manufacturing method of the flexible array piezoelectric sensor, the flexible substrate layer is formed on the first substrate, the first patterned lower electrode is formed on the flexible substrate layer, the flexible piezoelectric layer is formed on the lower electrode, the second patterned upper electrode is formed on the flexible piezoelectric layer, the third patterned insulating shielding layer is formed on the upper electrode, the flexible piezoelectric layer and the flexible substrate layer are etched with the insulating shielding layer as a mask until the surface of the substrate, so that the corresponding layers of the sensor array area are hollowed out through twice etching, the manufacturing process is relatively simple, and the packaging layer is subsequently formed on the shielding layer, the eighth projection pattern of the packaging layer on the flexible substrate layer is the same as the flexible substrate layer, so that the layers of the flexible array piezoelectric sensor are all curved and conformal, and the air permeability of the sensor is ensured.

[0178] Correspondingly, the embodiment of the present application also provides a flexible array piezoelectric sensor, please continue to refer to Figure 22 , comprising:

[0179] The flexible substrate layer 20 comprises an array area and a lead-out area adjacent to the array area, the array area comprises a plurality of array-arranged and mutually-separated sensing areas and interconnection areas connected between adjacent sensing areas, and gaps are provided between adjacent interconnection areas, and the interconnection areas are curved parallel to the central axis of the surface of the flexible substrate layer 20.

[0180] A lower electrode 30 is located on the flexible substrate layer 20, the lower electrode 30 comprises a plurality of first electrode parts 301 arranged in an array and separated from each other, and first interconnection lines 302 connected between adjacent first electrode parts 301 in a first direction, the first electrode parts 301 have a first projected pattern on the surface of the flexible substrate layer 20, the first projected pattern overlaps with the sensing area, and the first interconnection lines 302 have a second projected pattern on the surface of the flexible substrate layer 20, the second projected pattern partially overlaps with the lead-out area;

[0181] A flexible piezoelectric layer 40 is located on the lower electrode 30, the flexible piezoelectric layer 40 comprises a piezoelectric array area and a piezoelectric lead-out area adjacent to the piezoelectric array area, the piezoelectric array area has a third projected pattern on the surface of the flexible substrate layer 20, the third projected pattern overlaps with the sensing area, and the piezoelectric lead-out area has a fourth projected pattern on the surface of the flexible substrate layer 20, the fourth projected pattern partially overlaps with the lead-out area;

[0182] An upper electrode 50 is located on the flexible piezoelectric layer 40, the upper electrode 50 comprises a plurality of second electrode parts 501 arranged in an array and separated from each other, and second interconnection lines 502 connected between adjacent second electrode parts 501 in a second direction, the second electrode parts 501 have a fifth projected pattern on the surface of the flexible substrate layer 20, the fifth projected pattern overlaps with the sensing area, and the second interconnection lines 502 have a sixth projected pattern on the surface of the flexible substrate layer 20, the sixth projected pattern partially overlaps with the lead-out area;

[0183] An insulating shielding layer is located on the upper electrode 50, the insulating shielding layer has a seventh projected pattern on the surface of the flexible substrate layer 20, the seventh projected pattern overlaps with the sensing area;

[0184] An encapsulation layer 801 is located on the shielding layer 602, and an eighth projected pattern of the encapsulation layer 801 on the surface of the flexible substrate layer 20 overlaps with the flexible substrate layer 20.

[0185] Further, the application ensures that the array area of the sensor corresponds to each layer being hollow, and the interconnection area is a curve, so that the sensor has the characteristics of curved surface conforming, and the air permeability of the sensor is ensured.

[0186] In an embodiment, referring to Figure 22 The flexible substrate layer 20 comprises a flexible base 201 and a buffer layer 202 located on the flexible base 201.

[0187] In Figure 22In the example, the first direction and the second direction are perpendicular to each other. Of course, the present application is not limited to this, and one skilled in the art can control the orientation of the upper electrode 50 and the lower electrode 30 as needed.

[0188] For example, the material of the upper electrode 50 and the lower electrode 30 is a composite electrode of a high ductility metal material and indium tin oxide. This is because, after the formation of the flexible piezoelectric layer 40, the surface of the flexible piezoelectric layer 40 is not necessarily flat, and these high ductility metal materials can fill the pits and depressions on the surface of the flexible piezoelectric layer 40, so that the upper electrode 50 can be better attached to the flexible piezoelectric layer 40.

[0189] Therefore, the flexible array piezoelectric sensor provided by the present application includes a flexible substrate layer, a lower electrode, a flexible piezoelectric layer, an upper electrode, an insulating shielding layer and a packaging layer. The flexible substrate layer includes an array area and a lead-out area adjacent to the array area. The array area includes a plurality of sensing areas and interconnection areas. The interconnection areas are curved and have gaps between adjacent interconnection areas. The first electrode part of the lower electrode and the sensing areas are partially overlapped. The first interconnection line and part of the lead-out area are partially overlapped. The piezoelectric array area of the flexible piezoelectric layer and the sensing areas are partially overlapped. The piezoelectric lead-out area and part of the lead-out area are partially overlapped. The second electrode part of the upper electrode and the sensing areas are partially overlapped. The second interconnection line and part of the lead-out area are partially overlapped. The insulating shielding layer and the sensing areas are partially overlapped. The packaging layer and the flexible substrate layer are partially overlapped. Therefore, the present application ensures that the array area of the sensor corresponds to each layer being hollow, and the interconnection area is curved, so that the sensor has the characteristics of curved surface conforming, and the air permeability of the sensor is ensured.

[0190] Although the present application is disclosed as above, the present application is not limited to this. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application should be subject to the scope defined by the claims.

Claims

1. A flexible array piezoelectric sensor, characterized in that, include: A flexible substrate layer includes an array region and an exit region adjacent to the array region. The array region includes a plurality of sensing regions arranged in an array and being independent of each other, and an interconnection region connecting adjacent sensing regions. There is a gap between adjacent interconnection regions, and the interconnection region is a curve parallel to the central axis of the surface of the flexible substrate layer. The lower electrode located on the flexible substrate layer includes a plurality of first electrode portions arranged in an array and separated from each other, and a first interconnect line connected between adjacent first electrode portions along a first direction. The first electrode portions have a first projection pattern on the surface of the flexible substrate layer, and the first projection pattern overlaps with the sensing area. The first interconnect line has a second projection pattern on the surface of the flexible substrate layer, and the second projection pattern partially overlaps with the lead-out area. A flexible piezoelectric layer is located on the lower electrode. The flexible piezoelectric layer includes a piezoelectric array region and a piezoelectric lead-out region adjacent to the piezoelectric array region. The piezoelectric array region has a third projection pattern on the surface of the flexible substrate layer. The third projection pattern overlaps with the sensing region. The piezoelectric lead-out region has a fourth projection pattern on the surface of the flexible substrate layer. The fourth projection pattern partially overlaps with the lead-out region. The upper electrode located on the flexible piezoelectric layer includes a plurality of second electrode portions arranged in an array and separated from each other, and a second interconnect line connected between adjacent second electrode portions along a second direction. The second electrode portions have a fifth projection pattern on the surface of the flexible substrate layer, and the fifth projection pattern overlaps with the sensing area. The second interconnect line has a sixth projection pattern on the surface of the flexible substrate layer, and the sixth projection pattern partially overlaps with the lead-out area. An insulating shielding layer is located on the upper electrode, and the insulating shielding layer has a seventh projection pattern on the surface of the flexible substrate layer, which overlaps with the sensing area; An encapsulation layer is located on the shielding layer, and the eighth projection pattern of the encapsulation layer on the surface of the flexible substrate layer overlaps with the flexible substrate layer.

2. The flexible array piezoelectric sensor as described in claim 1, characterized in that, The first direction and the second direction are perpendicular to each other.

3. The flexible array piezoelectric sensor as described in claim 1, characterized in that, The flexible substrate layer includes a flexible substrate and a buffer layer located on the flexible substrate.

4. The flexible array piezoelectric sensor as described in claim 3, characterized in that, Both the upper electrode and the lower electrode are made of a composite electrode of a highly ductile metal material and indium tin oxide.

5. A method for fabricating a flexible array piezoelectric sensor, characterized in that, include: Provide a first substrate; A flexible substrate layer is formed on the first substrate, the flexible substrate layer including an array region and an exit region adjacent to the array region; A first patterned lower electrode is formed on the flexible substrate layer. The lower electrode includes a plurality of first electrode portions arranged in an array and being discrete from each other, and a first interconnect line connecting adjacent first electrode portions along a first direction. A flexible piezoelectric layer is formed on the lower electrode. The flexible piezoelectric layer includes a piezoelectric array region and a piezoelectric lead-out region adjacent to the piezoelectric array region. A second patterned upper electrode is formed on the flexible piezoelectric layer. The upper electrode includes a plurality of second electrode portions arranged in an array and being discrete from each other, and a second interconnect line connecting adjacent second electrode portions along a second direction. A third patterned insulating shielding layer is formed on the upper electrode; Using the insulating shielding layer as a mask, the flexible piezoelectric layer and the flexible substrate layer are etched until the surface of the first substrate, such that the array region includes a plurality of sensing regions arranged in an array and being mutually independent, and an interconnection region connected between adjacent sensing regions, with a gap between adjacent interconnection regions, and the interconnection region is a curve parallel to the central axis of the surface of the flexible substrate layer. The first electrode portion has a first projection pattern on the surface of the flexible substrate that overlaps with the sensing area, and the first interconnect has a second projection pattern on the surface of the flexible substrate that partially overlaps with the lead-out area. The third projection pattern of the piezoelectric array region on the surface of the flexible substrate overlaps with the sensing region, and the fourth projection pattern of the piezoelectric lead-out region on the surface of the flexible substrate partially overlaps with the lead-out region. The fifth projection pattern of the second electrode portion on the surface of the flexible substrate overlaps with the sensing area, and the sixth projection pattern of the second interconnect on the surface of the flexible substrate partially overlaps with the lead-out area. An encapsulation layer is formed on the insulating shielding layer, and the eighth projection pattern of the encapsulation layer on the surface of the flexible substrate layer overlaps with the flexible substrate layer. Remove the first substrate.

6. The method for fabricating the flexible array piezoelectric sensor as described in claim 5, characterized in that, Forming a flexible substrate layer on the first substrate includes: A flexible solution is spin-coated onto the substrate; After spin-coating the flexible solution, the flexible solution is annealed to obtain a flexible substrate; The flexible substrate is then cured. A buffer layer is deposited on the flexible substrate to form the flexible substrate layer.

7. The method for fabricating a flexible array piezoelectric sensor as described in claim 5, characterized in that, The pattern of the first patterned mask forming the first patterned lower electrode is perpendicular to the pattern of the second patterned mask forming the second pattern.

8. The method for fabricating a flexible array piezoelectric sensor as described in claim 5, characterized in that, The insulating shielding layer includes an insulating layer and a shielding layer, and a third patterned insulating shielding layer is formed on the upper electrode, including: An insulating layer is deposited on the upper electrode; A shielding layer is formed on the insulating layer by magnetron sputtering. The shielding layer is formed by photolithography using a third patterned mask.

9. The method for fabricating a flexible array piezoelectric sensor as described in claim 8, characterized in that, Using the insulating shielding layer as a mask, the flexible piezoelectric layer and the flexible substrate layer are etched down to the surface of the first substrate, including: Using the third patterned shielding layer as a mask, the insulating layer, the flexible piezoelectric layer, and the flexible substrate layer are etched sequentially until the surface of the first substrate is reached.

10. The method for fabricating the flexible array piezoelectric sensor as described in claim 5, characterized in that, An encapsulation layer is formed on the insulating shielding layer, including: Provide a second substrate; A second flexible substrate layer is formed on the second substrate; A second shielding layer is deposited on the second flexible substrate layer; Using a fourth patterned mask, the second shielding layer is photolithographically formed on the second flexible substrate to create the fourth patterned second shielding layer. Using the fourth patterned second shielding layer as a mask, the second flexible substrate layer is etched. The encapsulation layer is obtained by removing the fourth patterned second shielding layer and the second substrate; The encapsulation layer is attached to the surface of the insulating shielding layer.

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