Ultrasonic sensor array, device and manufacturing method

Abstract

The present invention discloses an ultrasonic sensor array, device, and manufacturing method. In one embodiment, the ultrasonic sensor array includes: a substrate; first electrodes arranged in an array, first connecting lines arranged in an array in a first direction and extending along a second direction, the first connecting lines connecting first electrodes adjacent in the second direction; second electrodes arranged in an array on a side of the first electrodes away from the substrate, second connecting lines arranged in an array in the second direction and extending along the first direction, the second connecting lines connecting second electrodes adjacent in the first direction; and a vibration unit arranged between the first and second electrodes; the projections of the first and second electrodes on the substrate overlap, the vibration unit is located at a position corresponding to the overlapping projections of the first and second electrodes, and the projections of the first and second connecting lines on the substrate do not overlap.

Description

Technical Field

[0001] The present invention relates to the field of ultrasonic sensing, and more particularly to an ultrasonic sensor array, device, and manufacturing method. Background Art

[0002] In related art, the capacitive ultrasonic sensor device structure not only forms capacitance in the vibration area of ​​the upper and lower electrodes, but also has a large coupling capacitance in the non-vibration area, which affects the performance of the ultrasonic sensor device structure in related art. Summary of the Invention

[0003] An object of the present invention is to provide an ultrasonic sensor array, a device and a manufacturing method to solve at least one of the problems existing in the prior art.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A first aspect of the present invention provides an ultrasonic sensor array, the sensor array comprising:

[0006] substrate;

[0007] The first electrodes are arranged in an array on the substrate,

[0008] First connecting lines arranged in an array in the first direction and extending along the second direction are provided on the substrate, the first connecting lines connecting adjacent first electrodes in the second direction;

[0009] a second electrode arranged in an array on a side of the first electrode away from the substrate,

[0010] second connecting lines arranged in an array in the second direction and extending along the first direction, the second connecting lines connecting adjacent second electrodes in the first direction, and

[0011] a vibration unit disposed between the first electrode and the second electrode;

[0012] The projections of the first electrode and the second electrode on the substrate overlap, the vibration unit is located at a position corresponding to the overlapping projections of the first electrode and the second electrode, and the projections of the first connecting line and the second connecting line on the substrate do not overlap.

[0013] Furthermore, the vibration unit includes:

[0014] a vibration cavity insulated from the first electrode,

[0015] A first filling layer is located between the adjacent vibration cavities, and the first filling layer and a surface of the vibration cavity away from the substrate are located in the same horizontal plane.

[0016] Furthermore, the vibration unit further includes:

[0017] A vibration membrane is provided on a surface of the vibration cavity away from the substrate, and the second electrode is located on a surface of the vibration membrane away from the substrate;

[0018] a second filling layer covering the second electrode and located between the adjacent vibration membranes, wherein the second filling layer is made of insulating material;

[0019] A surface of the second filling layer away from the substrate is higher than a surface of the second electrode away from the substrate.

[0020] Furthermore, the second connecting line is located on a surface of the second filling layer away from the substrate.

[0021] The second filling layer is provided with vias.

[0022] The second connection line connects the second electrodes adjacent to each other in the first direction through the via hole.

[0023] Furthermore, the projection of the second electrode on the substrate falls within the projection of the vibrating membrane on the substrate and exposes a portion of the surface of the vibrating membrane.

[0024] The second filling layer covers the exposed portion of the surface of the vibration membrane.

[0025] Furthermore, the vibration chamber includes:

[0026] a first cavity, wherein an area of ​​a projection of the first cavity on the substrate is equal to an area of ​​an overlapping projection of the first electrode and the second electrode;

[0027] A second cavity connected to the first cavity, wherein the second cavity is projected on the substrate and extends along a third direction, and the third direction forms an angle with the first direction or the second direction.

[0028] Furthermore, the area of ​​the projection of the first cavity on the substrate is equal to the area of ​​the projection of the first electrode on the substrate, and is equal to the area of ​​the projection of the second electrode on the substrate.

[0029] Furthermore, the projection length of the vibration membrane on the substrate in the first direction is greater than the projection length of the vibration cavity on the substrate in the first direction.

[0030] and / or

[0031] A projection length of the vibration membrane on the substrate in the second direction is greater than a projection length of the vibration cavity on the substrate in the second direction.

[0032] A second aspect of the present invention provides a device using the ultrasonic sensor array of the first aspect of the present invention, wherein the device is an ultrasonic fingerprint recognition device, a medical imaging device, or an ultrasonic ranging device.

[0033] A third aspect of the present invention provides a method for manufacturing the ultrasonic sensor array of the first aspect of the present invention, the method comprising:

[0034] forming an array of first electrodes on a substrate,

[0035] First connecting lines are formed on the substrate, arranged in an array in a first direction and extending in a second direction, the first connecting lines connecting adjacent first electrodes in the second direction; the vibration unit is formed on a side of the first electrode away from the substrate, and second electrodes are formed on a side of the vibration unit away from the substrate, the projections of the first electrode and the second electrode on the substrate overlap, and the vibration unit is located at a position corresponding to the overlapping projection of the first electrode and the second electrode;

[0036] A second connecting line is formed on a side of the first electrode away from the substrate. The second connecting lines are arranged in an array in the second direction and extend along the first direction, and are connected to second electrodes adjacent to each other in the first direction. The projections of the first connecting line and the second connecting line on the substrate do not overlap.

[0037] The beneficial effects of the present invention are as follows:

[0038] The sensor array proposed in an embodiment of the present invention utilizes a first electrode, a second electrode, and a vibration unit to form a sensor structure with capacitive ultrasonic receiving and transmitting functions, and utilizes a first connecting line and a second connecting line to realize an array structure of multiple sensor structures, and the projections of the first connecting line and the second connecting line on the substrate do not overlap. Through this arrangement, the coupling capacitance of the non-vibration area of ​​the sensor array can be reduced, thereby improving the device performance of the sensor array. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0040] Figure 1 and Figure 2 A cross-sectional schematic diagram and a planar schematic diagram showing the structure of a capacitive ultrasonic sensor device in the related art;

[0041] Figure 3 A schematic diagram showing the planar structure of an ultrasonic sensor array according to an embodiment of the present invention is shown;

[0042] Figure 4 Show Figure 1 Schematic diagram of poor collapse of the diaphragm above the cavity of the sensor device structure shown;

[0043] Figure 5 Shown Figure 3 Schematic diagram of the layer structure of the sensor array along the AA′ section;

[0044] Figure 6 Shown Figure 3 Schematic diagram of the layer structure of the sensor array along the BB′ section;

[0045] Figure 7 shows a schematic diagram of the arrangement of the first electrodes and the first connecting wires in a planar state;

[0046] Figure 8a and Figure 8b Shows the design relationship between the vibration membrane and the vibration cavity of different patterned shapes;

[0047] Figure 9 Show Figure 3 A schematic diagram of a sensor device structure in which the diaphragm above the cavity is normal is shown;

[0048] Figure 10 shows a schematic structural diagram of the vibration cavity in a planar state;

[0049] Figure 11 Schematic diagram of the layer structure of the vibration cavity at the CC' section;

[0050] Figure 12 A flow chart showing the steps of making a sensor array according to another embodiment of the present invention;

[0051] Figure 13 in Figure 13 a~ Figure 13 g is a process flow chart showing an embodiment of manufacturing a sensor array according to an embodiment of the present invention;

[0052] Figure 14 in Figure 14 a~ Figure 14 f shows a process flow chart of an embodiment of a sensor array according to an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to more clearly illustrate the present invention, the present invention will be further described below in conjunction with the embodiments and drawings. Similar components in the drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.

[0054] The device structure of the ultrasonic sensor in the related art is as follows Figure 1 and Figure 2 As shown, the first electrode 11 provided on the substrate 15 is a whole-surface electrode, the second electrode 12 is a patterned electrode, and the adjacent second electrodes 12 are connected by metal traces 14'. A vibration unit 16 is provided at the overlapping position of the second electrode 12 and the first electrode 11 to realize the transmitting and receiving functions of the sensor.

[0055] But for Figure 1 and Figure 2 In the sensor structure shown, at the overlapping position of the metal trace 14' and the first electrode, the metal trace 14' and the first electrode 11 are only blocked by the vibration membrane 163 and the third insulating layer 191, resulting in a large coupling capacitance being formed at the overlapping position of the metal trace 14' and the first electrode 11, seriously affecting the device performance of the sensor structure.

[0056] Therefore, embodiments of the present invention provide an ultrasonic sensor array, device, and manufacturing method to solve the above problems.

[0057] like Figure 3 、 Figure 5 and Figure 6 As shown, one embodiment of the present invention provides an ultrasonic sensor array, the sensor array comprising:

[0058] substrate 15;

[0059] The first electrodes 11 are arranged in an array on the substrate 15.

[0060] First connection lines 13 arranged in an array in the first direction and extending along the second direction, the first connection lines 13 connecting adjacent first electrodes 11 in the second direction;

[0061] The second electrodes 12 are arranged in an array on the side of the first electrode 11 away from the substrate 15.

[0062] second connecting lines 14 arranged in an array in the second direction and extending along the first direction, the second connecting lines 14 connecting the adjacent second electrodes 12 in the first direction, and

[0063] a vibration unit 16 disposed between the first electrode 11 and the second electrode 12;

[0064] The projections of the first electrode 11 and the second electrode 12 on the substrate 15 overlap, the vibration unit 16 is located at a position corresponding to the overlapping projections of the first electrode 11 and the second electrode 12, and the projections of the first connecting line 13 and the second connecting line 14 on the substrate 15 do not overlap.

[0065] like Figure 3 As shown, the first direction is the direction D1 shown in the figure, and the second direction is the direction D2 shown in the figure. The projections of the first connecting line 13, the first electrode 11, the second connecting line 14 and the second electrode 12 on the substrate 15 form an interlaced "field" structure. The vibration unit 16 forms a capacitor under the drive of the first electrode 11 and the second electrode 12 at its corresponding position to realize the sensing function. The first electrode 11, the second electrode 12 and the vibration unit 16 are used to form a sensor structure with capacitive ultrasonic receiving and transmitting functions, and the first connecting line 13 and the second connecting line 14 are used to realize an array structure of multiple sensor structures, and the projections of the first connecting line 13 and the second connecting line 14 on the substrate 15 do not overlap. Through this arrangement, the coupling capacitance of the non-vibration area of ​​the sensor array can be reduced, and the device performance of the sensor array can be improved.

[0066] like Figure 1 and Figure 2 The sensor structure shown not only has the problem of large coupling capacitance formed by the metal traces 14' and the first electrodes 11 arranged on the entire surface in the non-vibration area, but also has the problem of large coupling capacitance formed by the metal traces 14' and the first electrodes 11 arranged on the entire surface. Figure 1 and Figure 2 As shown, in the non-vibration area outside the vibration cavity 161, the first connecting line 13 and the first electrode 11 are electromagnetically shielded only by the vibration membrane 163 and the third insulating layer 191. Therefore, the electromagnetic shielding performance at this position is poor. In addition, in the process, the non-vibration area outside the vibration unit 16 will be subjected to an etching process before the etching of the vibration cavity 161. The metal material of the non-vibration area is etched and an etching hole is formed. Only the metal layer forming the vibration cavity 161 is retained. In other words, the non-vibration area outside the vibration cavity 161 is a hollow area with low strength. In addition, a whole layer of vibration membrane 163 is formed on the vibration cavity 161 in the vibration area and on the third insulating layer 191 in the non-vibration area. The supporting performance of the vibration membrane 163 set on the vibration cavity 161 is poor. Therefore, the overall strength of the non-vibration area and the vibration area is poor. The collapse of the vibration membrane 163 is likely to occur, thereby affecting the performance of the device. In a specific example, the vibration membrane located above the cavity collapses poorly, such as Figure 4 Therefore, the embodiment of the present invention further Figure 3 The sensor array shown is optimized.

[0067] In an optional embodiment, the first electrode 11 and the first connecting line 13 are provided in the same layer, and the second electrode 12 and the second connecting line 14 are provided in different layers. The same layer arrangement in this embodiment refers to realizing two different structures in the same process. For example, the first electrode 11 and the first connecting line 13 can be formed simultaneously in the same process. Figure 7As shown, the first electrode 11 is a patterned rectangle, and the first connecting line 13 connects the adjacent first electrodes 11 in the direction D2. A metal material layer can be formed on the substrate 15 by etching, and then the unnecessary metal material is etched to form Figure 7 The first electrode 11 and the first connecting line 13 are shown.

[0068] Figure 5 Shown Figure 3 Schematic diagram of the layer structure of the sensor array along the AA′ section shown, Figure 6 Shown Figure 3 Schematic diagram of the layer structure of the sensor array along the BB′ cross section.

[0069] In an optional embodiment, the vibration unit 16 includes:

[0070] The vibration cavity 161 is insulated from the first electrode 11,

[0071] The first filling layer 162 is located between the adjacent vibration cavities 161. The first filling layer 162 and the surface of the vibration cavity 161 away from the substrate 15 are located on the same horizontal plane, so that the vibration membrane 163 formed above the cavity in the subsequent process can maintain horizontal fit to ensure the vibration effect.

[0072] In the embodiment of the present invention, the vibration cavity 161 is a metal material made of conductive material, which provides a vibration space for the vibration of the vibration membrane 163. In this embodiment, a first filling layer 162 is provided before the adjacent vibration cavity 161, that is, the first filling layer 162 is provided in a non-vibration area, such as the area of ​​the first connecting line 13, or in the area of ​​the second connecting line 14, or, due to the patterned area surrounded by the first connecting line 13 and the second connecting line 14, the outer area of ​​the array-arranged vibration cavity 161 is filled. Through this arrangement, on the one hand, it can avoid Figure 1 The problem of diaphragm collapse that is prone to occur in the non-vibration area of ​​the sensor structure shown in the figure can be effectively avoided by using the first filling layer 162 to achieve electromagnetic shielding. Figure 1 The problem of large coupling capacitance caused by the short distance between the metal trace 14 ′ and the first electrode 11 in the non-vibration region of the sensor structure is solved, which not only improves the structural stability of the sensor array, but also improves the device performance of the sensor array.

[0073] In an optional embodiment, if Figure 5As shown, the sensor array further includes a first insulating layer 17 covering the first electrodes 11 and the substrate 15 between adjacent first electrodes 11. In the embodiment of the present invention, the first filling layer 162 is an organic material, and the dielectric constant of the first filling layer 162 is lower than the dielectric constant of the first insulating layer 17. By utilizing the low dielectric constant and easy flattening properties of organic materials, the first filling layer 162 is simple to manufacture and has a good electromagnetic shielding effect, thereby further improving the device performance of the sensor array.

[0074] In a specific example, the material of the first filling layer 162 is an organic resin material.

[0075] like Figure 1 As shown, two insulating layers, namely a fourth insulating layer 192 and a fifth insulating layer 193, are covered above the vibration membrane 163 and the second electrode 12, wherein the fourth insulating layer 192 is only provided in the vibration area, and the fourth insulating layer 192 in the non-vibration area is etched away to protect the second electrode 12, and the fifth insulating layer 193 is a whole-layer structure, which not only covers the fourth insulating layer 192 in the vibration area, but also covers the fifth insulating layer 193 in the non-vibration area, thereby protecting the sensor as a whole. However, this structure will cause the structure of the sensor array to collapse. Therefore, the embodiment of the present invention further optimizes the sensor array.

[0076] In an optional embodiment, if Figure 5 and Figure 6 As shown, the vibration unit 16 further includes:

[0077] A vibration membrane 163 is provided on a surface of the vibration cavity 161 away from the substrate 15 , and the second electrode 12 is located on a surface of the vibration membrane 163 away from the substrate 15 ;

[0078] The second filling layer 164 covers the second electrode 12 and is located between the adjacent vibration membranes 163. The second filling layer 164 is made of insulating material.

[0079] The surface of the second filling layer 164 away from the substrate 15 is higher than the surface of the second electrode 12 away from the substrate 15 .

[0080] Different from Figure 1 As shown in the sensor structure in which the non-vibration area is etched, in the embodiment of the present invention, the second filling layer 164 is used to fill the vibration area where the second electrode 12 and the vibration membrane 163 are located, as well as the non-vibration area between adjacent second electrodes 12. On the one hand, the surface of the vibration membrane 163 away from the vibration cavity 161 is fixed, and on the other hand, the non-vibration area is filled, thereby improving the overall performance of the device.

[0081] In an embodiment of the present invention, second filling layer 164 is made of an organic material. The dielectric constant of second filling layer 164 is lower than that of first insulating layer 17. Leveraging the low dielectric constant and easy planarization properties of organic materials, second filling layer 164 is simple to manufacture and provides excellent electromagnetic shielding, further enhancing the device performance of the sensor array. In one specific example, second filling layer 164 is made of an organic resin material.

[0082] In an optional embodiment, if Figure 5 As shown, the projection length of the vibration membrane 163 on the substrate 15 in the first direction is greater than the projection length of the vibration cavity 161 on the substrate 15 in the first direction. Figure 5 As shown, under the layer structure of the AA' section, the extension direction of the schematic diagram is the first direction, that is, the length of the vibration membrane 163 in this direction is greater than the length of the vibration cavity 161 in this direction. In other words, in the first direction, the projection of the vibration membrane 163 on the substrate 15 covers the projection of the vibration cavity 161 on the substrate 15. Through this arrangement, the vibration membrane 163 forms an overlap with the cavity side wall of the vibration cavity 161 in this direction in the first direction, and the cavity side wall of the vibration cavity 161 is used to support the vibration membrane 163, thereby further improving the structural strength of the sensor array.

[0083] In another optional embodiment, Figure 6 As shown, the projection length of the vibration membrane 163 on the substrate 15 in the second direction is greater than the projection length of the vibration cavity 161 on the substrate 15 in the second direction.

[0084] like Figure 6 As shown, under the layer structure of the BB' section, the extension direction of the schematic diagram is the second direction, that is, the length of the vibration membrane 163 in this direction is greater than the length of the vibration cavity 161 in this direction. In other words, in the second direction, the projection of the vibration membrane 163 on the substrate 15 covers the projection of the vibration cavity 161 on the substrate 15. Through this arrangement, the vibration membrane 163 forms an overlap with the cavity side wall of the vibration cavity 161 in this direction in the second direction, and the cavity side wall of the vibration cavity 161 is used to support the vibration membrane 163, thereby further improving the structural strength of the sensor array.

[0085] In a specific example, Figure 8a As shown, if the projections of the vibration membrane 163 and the vibration cavity 161 on the substrate 15 are both circular, then the radius of the vibration membrane 163 and the vibration cavity 161 is designed to be R 振动膜 =1.2R 振动腔 , that is, the vibration membrane 163 can completely cover the vibration cavity 161.

[0086] In another specific example, Figure 8b If the projections of the vibration membrane 163 and the vibration cavity 161 on the substrate 15 are both rectangular, then the vibration membrane 163 includes long sides and short sides, where the relative long sides overlap with the vibration cavity 161, which is approximately a "+" shape, and can also provide support for the vibration membrane 163 in the extension direction of the long sides.

[0087] Therefore, the relative relationship between the vibration membrane 163 and the vibration cavity 161 can have any one of the two embodiments mentioned above or a common solution of the two embodiments, so that the edge of the vibration membrane 163 and the cavity side wall of the vibration cavity 161 can form an overlapping relationship, and the cavity side wall of the vibration cavity 161 is used to support the vibration membrane 163.

[0088] Based on the above embodiment, according to the different pattern designs of the projection of the vibration membrane 163 on the substrate 15, the embodiment of the present invention does not limit the pattern designs of the vibration membrane 163 with different patterns and the vibration cavity 161 with different patterns, but it is necessary to ensure that the projection of the vibration membrane 163 on the substrate 15 covers the projection of the vibration cavity 161 on the substrate 15 in a certain direction, that is, the edge of the membrane layer of the vibration membrane 163 is located outside the cavity of the vibration cavity 161 to form an overlapping relationship, further improving the support of the vibration membrane 163, and improving the vibration cavity 161. Figure 4 The problem of the vibration membrane 163 collapsing is shown.

[0089] In a specific example, Figure 9 As shown, the supporting performance of the vibration membrane 163 above the cavity of the embodiment of the present invention is better. Figure 1 The sensor structure of the related art shown has a greatly improved structural strength.

[0090] In an optional embodiment, if Figure 5 and Figure 6 As shown, the projection of the second electrode 12 on the substrate 15 falls within the projection of the vibration membrane 163 on the substrate 15 and exposes a portion of the surface of the vibration membrane 163 , and the second filling layer 164 covers the exposed portion of the surface of the vibration membrane 163 .

[0091] In the aforementioned embodiment, the overall structural performance of the sensor array is improved by designing the projection relationship between the vibration membrane 163 and the vibration cavity 161. In this embodiment, a second filling layer 164 is further provided on the side of the vibration membrane 163 away from the cavity, so that the projection surface of the second electrode 12 is smaller than the projection area of ​​the vibration membrane 163, thereby exposing the surface of the vibration membrane 163 away from the vibration cavity 161. The second filling layer 164 is used to cover the exposed surface of the vibration membrane 163, and the edge of the vibration membrane 163 is further fixed, thereby further improving the structural strength of the sensor structure and avoiding the collapse of the vibration membrane 163.

[0092] Figure 10 shows a schematic structural diagram of the vibration cavity 161 in a planar state, Figure 11 A schematic diagram of the layer structure of the vibration cavity 161 at the CC' cross section is shown. In an optional embodiment, the vibration cavity 161 includes a first cavity 1611 and a second cavity 1612. In this embodiment, the projected length of the vibration cavity 161 in the third direction is greater than the projected lengths of the first electrode 11, the vibration membrane 163, and the second electrode 12 in the third direction. In other words, the vibration cavity 161 has the largest extension length in the third direction, wherein the extension length of the projection of the first cavity 1611 in the third direction is less than the extension length of the projection of the second cavity 1612 in the third direction, so that the first cavity 1611 is formed by the second cavity 1612.

[0093] Furthermore, in an optional embodiment, the projected area of ​​the first cavity 1611 on the substrate 15 is equal to the area of ​​the overlapping projection of the first electrode 11 and the second electrode 12. Since the overlapping area of ​​the first electrode 11 and the second electrode 12 affects the capacitive performance of the sensor, in this embodiment, the first cavity 1611 is not only provided at the position where the first electrode 11 and the second electrode 12 overlap, but the projected area of ​​the first cavity 1611 is also set to be equal to the area of ​​the overlapping projection of the first electrode 11 and the second electrode 12, thereby optimizing the sensing performance of the sensor array.

[0094] like Figure 10 As shown, the second cavity 1612 is connected to the first cavity 1611 and is used to form the first cavity 1611 by etching in the etching process. The second cavity 1612 is projected on the substrate 15 and extends along a third direction. The third direction forms an angle with the first direction or the second direction. That is, the extension direction of the second cavity 1612 of this embodiment is different from the direction of the first connecting line 13 and the second connecting line 14, thereby simplifying the structural design at the location of the first connecting line 13 and the second connecting line 14 and improving the overall performance of the sensor structure.

[0095] In an optional embodiment, the area of ​​the projection of the first cavity 1611 on the substrate 15 is equal to the area of ​​the projection of the first electrode 11 on the substrate 15 , and is equal to the area of ​​the projection of the second electrode 12 on the substrate 15 .

[0096] Based on the foregoing discussion, the overlapping area of ​​the first electrode 11 and the second electrode 12 affects the capacitive performance of the sensor. Therefore, in this embodiment, the projected area between the first cavity 1611, the first electrode 11, and the second electrode 12 is designed to ensure that the sensor array has optimal sensing performance.

[0097] In an alternative embodiment, from Figure 6 From the cross-sectional view along line BB', the second connecting line 14 is located on the surface of the second filling layer 164 away from the substrate 15.

[0098] The second filling layer 164 is provided with a via hole 1641.

[0099] The second connection line 14 is connected to the second electrodes 12 adjacent to each other in the first direction through the via hole 1641 .

[0100] In this embodiment, a plurality of second electrodes 12 adjacent to each other in the first direction are connected by second connection lines 14 extending along the first direction. To ensure normal operation of the circuit, in this embodiment, a bridge structure between the second electrodes 12 and the second connection lines 14 is formed by vias 1641 .

[0101] In this embodiment, the distance between the surface of the second filling layer 164 on the side away from the substrate 15 and the substrate 15 is greater than the distance between the surface of the second electrode 12 on the side away from the substrate 15 and the substrate 15, that is, in the stacking direction, the thickness of the second filling layer 164 is greater than the thickness of the second electrode 12, which not only ensures the array setting between adjacent second electrodes 12, but also realizes the scheme of connecting the second connecting line 14 to the adjacent second electrodes 12 through the via 1641 to achieve electrical connection.

[0102] Different from the first electrode 11 and the first connecting line 13 of the aforementioned embodiment, in an optional embodiment, the second electrode 12 and the second connecting line 14 are arranged in different layers, that is, Figure 5 As shown, the second electrode 12 is formed first, and then the second connection line 14 is formed, and a bridge structure is used to ensure that the circuit is normal.

[0103] In an optional embodiment, the excitation voltage of the sensor array of the embodiment of the present invention is 50-100V.

[0104] In an optional embodiment, when the projections of the first cavity and the vibration membrane on the substrate are both circular, the resonant frequency f of the sensor array of the embodiment of the present invention isr The calculation formula is:

[0105]

[0106] Among them, t m is the thickness of the vibration membrane, α is the radius of the first cavity, Y is the Young's modulus of the vibration membrane, and ρ is the density of the vibration membrane.

[0107] Another embodiment of the present invention provides a device using the ultrasonic sensor array of the above embodiment. The device is a device with a sensing function, such as an ultrasonic fingerprint recognition device, a medical imaging device, and an ultrasonic ranging device, and has a wide range of application scenarios.

[0108] In another embodiment of the present invention, the refractive index of the first sensing layer and the refractive index of the second sensing layer are both greater than the refractive index of the first adhesive layer. A method for manufacturing the ultrasonic sensor array of the above embodiment is provided, such as Figure 12 As shown, the method includes:

[0109] S1, forming an array of first electrodes 11 on a substrate 15,

[0110] S3, forming first connecting lines 13 arranged in an array in the first direction and extending along the second direction on the substrate 15, wherein the first connecting lines 13 are connected to adjacent first electrodes 11 in the second direction;

[0111] S5. Forming the vibration unit 16 on a side of the first electrode 11 away from the substrate 15 and forming an array of second electrodes 12 on a side of the vibration unit 16 away from the substrate 15, wherein the projections of the first electrode 11 and the second electrode 12 on the substrate 15 overlap, and the vibration unit 16 is located at a position corresponding to the overlapping projections of the first electrode 11 and the second electrode 12;

[0112] S7. Form a second connecting line 14 on the side of the first electrode 11 away from the substrate 15. The second connecting lines 14 are arranged in an array in the second direction and extend along the first direction, and are connected to the second electrodes 12 adjacent to each other in the first direction. The projections of the first connecting line 13 and the second connecting line 14 on the substrate 15 do not overlap.

[0113] The manufacturing method of the embodiment of the present invention has simple steps and processes and does not add complex manufacturing processes. The sensor structure formed by this method can reduce the coupling capacitance of the non-vibration area of ​​the sensor array and improve the device performance of the sensor array.

[0114] Now Figure 3 As an example, the sensor array shown in Figure 12 The method shown is explained.

[0115] S1. Forming first electrodes 11 arranged in an array on a substrate 15.

[0116] In a specific example, a metal layer of a certain thickness, such as Mo or ITO, is deposited on the substrate 15 by a sputtering device, and then patterned by photolithography and etching processes.

[0117] S3 , forming first connection lines 13 arranged in an array in the first direction and extending along the second direction on the substrate 15 , wherein the first connection lines 13 connect adjacent first electrodes 11 in the second direction.

[0118] In a specific example, the first electrode 11 and the first connecting line 13 of this embodiment can be formed by the same process. For example, a metal layer of a certain thickness, such as Mo or ITO, is deposited on the substrate 15 by a sputtering device, and then the first electrode 11 and the first connecting line 13 are patterned by photolithography and etching processes to form Figure 7 The plan view shown in FIG. Figure 13 Schematic diagram of the layer structure formed in 13a. This method can save process steps and improve process efficiency.

[0119] S5. Forming the vibration unit 16 on a side of the first electrode 11 away from the substrate 15 and forming an array of second electrodes 12 on a side of the vibration unit 16 away from the substrate 15, wherein the projections of the first electrode 11 and the second electrode 12 on the substrate 15 overlap, and the vibration unit 16 is located at a position corresponding to the overlapping projections of the first electrode 11 and the second electrode 12.

[0120] In an optional embodiment, step S5 includes the following steps:

[0121] S51 . Form a vibration cavity material layer 161A on a side of the first electrode 11 away from the substrate 15 , which is insulated from the first electrode 11 .

[0122] In an optional embodiment, step S51 of “forming a vibration cavity 161 on a side of the first electrode 11 away from the substrate 15 and insulated from the first electrode 11 ” further includes:

[0123] S511, forming a first insulating layer 17 on the side of the first electrode 11 away from the substrate 15, such as Figure 13 Schematic diagram of the layer structure formed by 13b;

[0124] S513, forming a metal material layer on the surface of the first insulating layer 17 away from the substrate 15, and forming a patterned vibration cavity material layer 161A at a position corresponding to the first electrode 11, forming Figure 13 middle Figure 13 c shows the layer structure.

[0125] In a specific example, the vibration cavity material layer 161A includes a first cavity material layer and a second cavity material layer, and its planar schematic diagram when viewed from above is as follows: Figure 10 As shown, the first cavity material layer is used to form a first cavity 1611 , and the second cavity material layer is used to form a second cavity 1612 .

[0126] In a specific example, a metal material layer of a certain thickness is first deposited on the first insulating layer 17, and then the metal material of the non-vibration area that is not required to form the vibration cavity 161 is removed by photolithography and etching processes to form Figure 13 middle Figure 13 c shows the layer structure.

[0127] S53, forming a first filling layer 162 between the adjacent vibration cavity material layers 161A, wherein the first filling layer 162 and the surface of the vibration cavity material layer 161A away from the substrate 15 are located at the same horizontal plane, thereby forming Figure 13 middle Figure 13 d shows the layer structure.

[0128] Exemplarily, the etched metal material layer is filled with an organic resin material. Exemplarily, the height of the first filling layer 162 is the same as the height of the vibration cavity material layer 161A.

[0129] In an optional embodiment, step S4 of “forming the vibration unit 16 on a side of the first electrode 11 away from the substrate 15 ” further includes:

[0130] S55 , forming a vibration membrane material layer 163A on the surface of the vibration cavity material layer 161A away from the substrate 15 .

[0131] In a specific example, a vibration membrane material layer 163A is first formed on the side of the vibration cavity material layer 161A and the first filling layer 162 away from the substrate 15, forming Figure 13 middle Figure 13 e shows the layer structure.

[0132] S57 , forming a second electrode 12 on the surface of the vibration membrane material layer 163A away from the substrate 15 , and patterning the vibration membrane material layer 163A using the second electrode 12 as a shielding layer.

[0133] The second electrode 12 is formed at the position of the vibration membrane material layer 163A corresponding to the first electrode 11. Figure 13 middle Figure 13 The layer structure shown in f. Figure 13 middle Figure 13 Based on f, the vibration membrane material layer 163A is patterned to form Figure 13 The structure of g.

[0134] S59 , etching the vibration cavity material layer 161A with an etching solution to form the vibration cavity 161 .

[0135] In a specific example, the vibration cavity material layer 161A formed based on the above steps is as follows: Figure 10 As shown, it includes a vibration cavity material layer forming a first cavity 1611 and a second vibration cavity material layer forming a second cavity 1612. In the third direction, the projection of the vibration cavity material layer 161A of the first cavity 1611 is located outside the projection of the vibration cavity material layer 161A of the second cavity 1612. The etching liquid is introduced through the vibration cavity material layer 161A of the second cavity 1612 from the outside and the vibration cavity material layer 161A of the first cavity 1611 is etched, and then the vibration cavity 161 can be formed. The vibration cavity 161 is formed as the first cavity 1611 at the position corresponding to the second electrode 12, and the cavity outside the first cavity 1611 is the second cavity 1612.

[0136] S61, forming a second filling layer 164 covering the second electrode 12 and located between the adjacent vibration membranes 163, the second filling layer 164 is an insulating material, and the surface of the second filling layer 164 away from the substrate 15 is higher than the surface of the second electrode 12 away from the substrate 15.

[0137] In a specific example, after forming the second filling layer 164, the second filling layer 164 is further opened, such as Figure 14 As shown in FIG. 1 a , the projection of the via hole 1641 on the substrate 15 falls within the projection of the second electrode 12 on the substrate 15 , and the second electrode 12 and the subsequently formed second connection line 14 are connected through the via hole 1641 .

[0138] S7. Form second connecting lines 14 on the side of the first electrode 11 away from the substrate 15. The second connecting lines 14 are arranged in an array in the second direction and extend along the first direction, and are connected to the adjacent second electrodes 12 in the first direction.

[0139] In a specific example, step S7 includes:

[0140] S71, forming a second connection line metal layer 14A on the second filling layer 164 and in the via hole 1641 of the second filling layer 164, thereby forming Figure 14 in Figure 14 The layer structure of b.

[0141] S72, forming a sacrificial layer 165 on the second connection line metal layer 14A, the sacrificial layer 165 covering the second connection line metal layer 14A in the adjacent via holes 1641 in the first direction, and covering the second connection line metal layer 14A between the adjacent via holes 1641, thereby forming Figure 14 in Figure 14 The layer structure of c.

[0142] S73, using the sacrificial layer 165 as a shield, etching the second connection line metal layer 14A exposed by the sacrificial layer 165 to form the second connection line 14, as shown in FIG. Figure 14 in Figure 14 d layer structure.

[0143] S74, peeling off the sacrificial layer 165 to form Figure 14 in Figure 14 The layer structure of e.

[0144] S75, forming a second insulating layer 18 on the second connecting line 14 and the second filling layer 164, forming Figure 14 in Figure 14 The layer structure of f.

[0145] Based on the above steps, the sensor array of the embodiment of the present invention is formed. The entire process is simple and efficient, and can reduce the coupling capacitance of the non-vibration area of ​​the sensor array and improve the device performance of the sensor array.

[0146] It is worth noting that the specific embodiment of the method for manufacturing the sensor array according to the embodiment of the present invention can be found in the sensor array according to the aforementioned embodiment, which will not be described in detail here.

[0147] In the description of the present invention, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0148] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in this field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. An ultrasonic sensor array, characterized in that: The sensor array comprises: substrate; The first electrodes are arranged in an array on the substrate, First connecting lines arranged in an array in the first direction and extending along the second direction are provided on the substrate, the first connecting lines connecting adjacent first electrodes in the second direction; a second electrode arranged in an array on a side of the first electrode away from the substrate, second connecting lines arranged in an array in the second direction and extending along the first direction, the second connecting lines connecting adjacent second electrodes in the first direction, and a vibration unit disposed between the first electrode and the second electrode; The projections of the first electrode and the second electrode on the substrate overlap, the vibration unit is located at a position corresponding to the overlapping projections of the first electrode and the second electrode, and the projections of the first connecting line and the second connecting line on the substrate do not overlap, Wherein, the vibration unit includes: a vibration cavity insulated from the first electrode, wherein the vibration cavity is formed by etching a vibration cavity material layer made of a conductive material, and A first filling layer is located between the adjacent vibration cavities, and the first filling layer and a surface of the vibration cavity away from the substrate are located in the same horizontal plane.

2. The sensor array according to claim 1, wherein: The vibration unit further includes: A vibration membrane is provided on a surface of the vibration cavity away from the substrate, and the second electrode is located on a surface of the vibration membrane away from the substrate; a second filling layer covering the second electrode and located between the adjacent vibration membranes, wherein the second filling layer is made of insulating material; A surface of the second filling layer away from the substrate is higher than a surface of the second electrode away from the substrate.

3. The sensor array according to claim 2, wherein: The second connecting line is located on a surface of the second filling layer away from the substrate. The second filling layer is provided with vias. The second connection line connects the second electrodes adjacent to each other in the first direction through the via hole.

4. The sensor array according to claim 3, characterized in that The projection of the second electrode on the substrate falls within the projection of the vibration membrane on the substrate and exposes a portion of the surface of the vibration membrane. The second filling layer covers the exposed portion of the surface of the vibration membrane.

5. The sensor array according to claim 2, wherein: The vibration chamber comprises: a first cavity, wherein an area of ​​a projection of the first cavity on the substrate is equal to an area of ​​an overlapping projection of the first electrode and the second electrode; A second cavity connected to the first cavity, wherein the second cavity is projected on the substrate and extends along a third direction, and the third direction forms an angle with the first direction or the second direction.

6. The sensor array according to claim 5, characterized in that An area of ​​a projection of the first cavity on the substrate is equal to an area of ​​a projection of the first electrode on the substrate, and is also equal to an area of ​​a projection of the second electrode on the substrate.

7. The sensor array according to claim 5, characterized in that The projection length of the vibration membrane on the substrate in the first direction is greater than the projection length of the first cavity on the substrate in the first direction. and / or A projection length of the vibration membrane on the substrate in the second direction is greater than a projection length of the first cavity on the substrate in the second direction.

8. A device using the ultrasonic sensor array according to any one of claims 1 to 7, characterized in that: The equipment is an ultrasonic fingerprint recognition equipment, a medical imaging equipment, and an ultrasonic ranging equipment.

9. A method for manufacturing an ultrasonic sensor array according to any one of claims 1 to 7, characterized in that: The method comprises: forming an array of first electrodes on a substrate, First connecting lines are formed on the substrate, arranged in an array in a first direction and extending in a second direction, the first connecting lines connecting adjacent first electrodes in the second direction; the vibration unit is formed on a side of the first electrode away from the substrate, and second electrodes are formed on a side of the vibration unit away from the substrate, the projections of the first electrode and the second electrode on the substrate overlap, and the vibration unit is located at a position corresponding to the overlapping projection of the first electrode and the second electrode; A second connecting line is formed on a side of the first electrode away from the substrate. The second connecting lines are arranged in an array in the second direction and extend along the first direction, and are connected to second electrodes adjacent to each other in the first direction. The projections of the first connecting line and the second connecting line on the substrate do not overlap.

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