A microelectromechanical device (MEMS), a method for fabricating a MEMS, and an electronic device.

Abstract

This application provides a microelectromechanical device (MEMS), a method for fabricating a MEMS, and an electronic device. The MEMS includes a piezoelectric actuation structure and a cover plate structure. The piezoelectric actuation structure includes a substrate and a piezoelectric actuation unit. The piezoelectric actuation unit is disposed on one side of the substrate, and the cover plate structure is connected to the substrate. A cavity is formed between the cover plate structure and the substrate, and the piezoelectric actuation unit is located within the cavity. The piezoelectric actuation unit is used to generate vibration under electrical signal excitation. By setting up the piezoelectric actuation unit, heat dissipation is achieved by utilizing the vibration of the piezoelectric actuation unit. Compared with the use of fans for heat dissipation in related technologies, this reduces operating noise and improves the user experience.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and in particular to a microelectromechanical device (MEMS), a method for fabricating a MEMS, and an electronic device. Background Technology

[0002] Traditional integrated circuit heat sinks mainly consist of components such as fans, heat sink fins, and heat pipes. The fan is responsible for generating airflow, the heat sink fins are used to increase the heat dissipation area, and the heat pipes are responsible for transferring heat from the integrated circuit to the heat sink fins, and finally the heat is dissipated by the fan.

[0003] However, when the aforementioned integrated circuit heat sink is working, the fan generates significant noise, affecting the user's experience. Summary of the Invention

[0004] The purpose of this application is to provide a microelectromechanical device (MEMS), a method for fabricating a MEMS, and an electronic device to improve the user experience. The specific technical solution is as follows:

[0005] In a first aspect, embodiments of this application provide a microelectromechanical device, including:

[0006] Piezoelectric actuation structure and cover plate structure; the piezoelectric actuation structure includes a substrate and a piezoelectric actuation unit;

[0007] The piezoelectric actuation unit is located on one side of the substrate, and the cover plate structure is connected to the substrate;

[0008] A cavity is formed between the cover plate structure and the substrate, and the piezoelectric actuation unit is located inside the cavity;

[0009] Piezoelectric actuators are used to generate vibrations when excited by electrical signals.

[0010] In one possible implementation, the piezoelectric actuation unit includes an etch stop layer, a first passivation layer, a first electrode layer, a piezoelectric layer, a second passivation layer, and a second electrode layer.

[0011] An etch stop layer is disposed on the substrate, a first passivation layer is disposed on the side of the etch stop layer away from the substrate, a first electrode layer is disposed on the side of the first passivation layer away from the substrate, a piezoelectric layer is disposed on the side of the first electrode layer away from the substrate, a second passivation layer is disposed on the side of the piezoelectric layer away from the substrate, and a second electrode layer is disposed on the side of the second passivation layer away from the substrate.

[0012] In one possible implementation, the cover structure includes an air inlet cover and an air outlet cover.

[0013] The air inlet cover is located on one side of the substrate, and the air outlet cover is located on the other side of the substrate.

[0014] The air inlet cover includes a first protective part and a first edge annular protrusion, and the first edge annular protrusion of the air inlet cover is bonded to the edge of the substrate.

[0015] A first cavity is formed between the air inlet cover and the substrate; the piezoelectric actuation unit is located inside the first cavity;

[0016] The vent cover includes a second protective portion and a second edge annular protrusion, the second edge annular protrusion of the vent cover being bonded to the edge of the substrate;

[0017] A second cavity is formed between the vent cover and the substrate;

[0018] The second protective section is provided with at least one air outlet that penetrates the second protective section, and the multiple air outlets are arranged in an array when projected onto the substrate plane.

[0019] In one possible implementation, the orthographic projection of the vent onto the substrate plane is circular.

[0020] In one possible implementation, a vent penetrating the substrate is provided in the middle of the substrate;

[0021] Along the length of the microelectromechanical device, the orthographic projection of the vent on the plane of the second protection part is in the shape of an "I".

[0022] The piezoelectric actuation unit includes a first subunit and a second subunit. The orthographic projection of the first subunit on the substrate plane is arranged in one side opening of the "I"-shaped vent, and the orthographic projection of the second subunit on the substrate plane is arranged in the other side opening of the "I"-shaped vent.

[0023] In one possible implementation, an air inlet penetrating the first protective portion is provided in the middle of the first protective portion of the air inlet cover plate;

[0024] The orthographic projections of the air inlet and outlet onto the substrate plane do not overlap.

[0025] In one possible implementation, a first concave region and a second concave region are provided on the side of the substrate facing the outlet cover plate;

[0026] The orthographic projection of the first sub-unit onto the substrate plane is included in the first concave region, and the orthographic projection of the second sub-unit onto the substrate plane is included in the second concave region.

[0027] In one possible implementation, the first protective portion of the air inlet cover is provided with a first air inlet penetrating the first protective portion and a second air inlet penetrating the first protective portion.

[0028] The first air inlet and the first sub-unit have overlapping portions when projected onto the substrate plane, and the second air inlet and the second sub-unit have overlapping portions when projected onto the substrate plane.

[0029] A first concave region and a second concave region are provided on the side of the substrate facing the outlet cover plate;

[0030] The orthographic projection of the first sub-unit onto the substrate plane is included in the first concave region, and the orthographic projection of the second sub-unit onto the substrate plane is included in the second concave region.

[0031] In one possible implementation, in the width direction of the microelectromechanical device, the first edge annular protrusion of the air inlet cover is provided with a first air inlet penetrating the first edge annular protrusion and a second air inlet penetrating the first edge annular protrusion.

[0032] The first air intake is located close to the first sub-unit, and the second air intake is located close to the second sub-unit;

[0033] A first concave region and a second concave region are provided on the side of the substrate facing the outlet cover plate;

[0034] The orthographic projection of the first sub-unit onto the substrate plane is included in the first concave region, and the orthographic projection of the second sub-unit onto the substrate plane is included in the second concave region.

[0035] In one possible implementation, the vent cover also includes a central protrusion;

[0036] The central protrusion and the second edge annular protrusion are located on the same side of the second protective part;

[0037] The width of the central bulge is smaller than the width of the central area of ​​the vent.

[0038] The length of the central protrusion is greater than or equal to the length of the vent.

[0039] The thickness of the central protrusion is greater than or equal to 0.9 times the thickness of the second edge annular protrusion, and less than or equal to the thickness of the second edge annular protrusion.

[0040] In one possible implementation, a vent penetrating the substrate is provided in the middle of the substrate;

[0041] Along the length of the microelectromechanical device, the orthographic projection of the vent onto the plane of the second protective part is in the shape of a bracket.

[0042] The piezoelectric actuation unit includes a first subunit and a second subunit. The orthographic projection of the first subunit on the substrate plane is arranged in one side opening of the "bracket"-shaped vent, and the orthographic projection of the second subunit on the substrate plane is arranged in the other side opening of the "bracket"-shaped vent.

[0043] An air inlet penetrating the first protective section is provided in the middle of the first protective section of the air inlet cover;

[0044] The orthographic projections of the air inlet and outlet onto the substrate plane do not overlap.

[0045] A first concave region and a second concave region are provided on the side of the substrate facing the outlet cover plate;

[0046] The orthographic projection of the first sub-unit onto the substrate plane is included in the first concave region, and the orthographic projection of the second sub-unit onto the substrate plane is included in the second concave region;

[0047] The vent cover also includes a central support protrusion;

[0048] The central support protrusion and the second edge annular protrusion are located on the same side of the second protective part;

[0049] The orthographic projection of the central support protrusion onto the substrate plane does not overlap with the first concave region, and the orthographic projection of the central support protrusion onto the substrate plane does not overlap with the second concave region.

[0050] The thickness of the central support protrusion is equal to the thickness of the second edge annular protrusion.

[0051] In one possible implementation, the cover structure includes an air outlet cover;

[0052] The vent cover includes a second protective portion and a second edge annular protrusion, the second edge annular protrusion of the vent cover being bonded to the edge of the substrate;

[0053] A second cavity is formed between the vent cover and the substrate; the piezoelectric actuation unit is located inside the second cavity;

[0054] The second protective part is provided with at least one air outlet penetrating the second protective part, and the multiple air outlets are arranged in an array on the orthographic projection of the substrate plane.

[0055] An air inlet penetrating the substrate is provided in the middle of the substrate;

[0056] The orthographic projections of the air inlet and outlet onto the substrate plane do not overlap.

[0057] The piezoelectric actuation unit includes a first subunit and a second subunit. In the width direction of the microelectromechanical device, the first subunit is arranged on one side of the air inlet by its orthogonal projection on the substrate plane, and the second subunit is arranged on the other side of the air inlet by its orthogonal projection on the substrate plane.

[0058] The vent cover also includes a central protrusion;

[0059] The central protrusion and the second edge annular protrusion are located on the same side of the second protective part;

[0060] The width of the central protrusion is smaller than the width of the air intake.

[0061] The length of the central protrusion is greater than or equal to the length of the air intake.

[0062] The thickness of the central protrusion is greater than or equal to 0.5 times the thickness of the second edge annular protrusion, and less than or equal to 0.8 times the thickness of the second edge annular protrusion.

[0063] In one possible implementation, the orthographic projection of the vent onto the substrate plane is circular.

[0064] In one possible implementation, the orthographic projection of the air inlet onto the substrate plane is rectangular.

[0065] In one possible implementation, the orthographic projection of the first air inlet onto the substrate plane is a rectangle, and the orthographic projection of the second air inlet onto the substrate plane is a rectangle.

[0066] In one possible implementation, the substrate is a semiconductor material substrate, or the substrate is a glass-based material substrate;

[0067] The cover plate structure is a semiconductor material cover plate structure.

[0068] Secondly, embodiments of this application provide a method for fabricating a microelectromechanical device, comprising:

[0069] A pre-fabricated piezoelectric actuation structure is obtained; wherein the piezoelectric actuation structure includes a substrate and a piezoelectric actuation unit, and the piezoelectric actuation unit is disposed on one side of the substrate;

[0070] Obtain the pre-prepared cover plate structure;

[0071] By connecting the cover plate structure to the substrate, a microelectromechanical device (MEMS) is obtained; wherein, a cavity is formed between the cover plate structure and the substrate, and the piezoelectric actuation unit is located in the cavity.

[0072] Thirdly, embodiments of this application provide an electronic device, which includes a flexible circuit board, multiple ground lines arranged along the row direction, multiple AC voltage signal lines arranged along the column direction, and multiple microelectromechanical devices as described in the first aspect above.

[0073] Each microelectromechanical device (MEMS) in the Nth row is electrically connected to the Nth ground line, and each MEMS in the Mth column is electrically connected to the Mth AC voltage signal line; where N is an integer greater than or equal to 1, and M is an integer greater than or equal to 1.

[0074] The ground wire is electrically connected to the flexible circuit board, and the AC voltage signal line is also electrically connected to the flexible circuit board; the flexible circuit board is used to drive the ground wire and the AC voltage signal line respectively.

[0075] Beneficial effects of the embodiments in this application:

[0076] This application provides a microelectromechanical device (MEMS), a method for fabricating a MEMS, and an electronic device. The MEMS includes a piezoelectric actuation structure and a cover plate structure. The piezoelectric actuation structure includes a substrate and a piezoelectric actuation unit. The piezoelectric actuation unit is disposed on one side of the substrate, and the cover plate structure is connected to the substrate. A cavity is formed between the cover plate structure and the substrate, and the piezoelectric actuation unit is located within the cavity. The piezoelectric actuation unit is used to generate vibration under electrical signal excitation. By setting up the piezoelectric actuation unit, heat dissipation is achieved by utilizing the vibration of the piezoelectric actuation unit. Compared with the use of fans for heat dissipation in related technologies, this reduces operating noise and improves the user experience.

[0077] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0078] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0079] Figure 1 A schematic diagram of the first structure of the microelectromechanical device provided in the embodiments of this application (a schematic cross-section diagram in the AA' direction);

[0080] Figure 2a A schematic diagram of a second structure of the microelectromechanical device provided in the embodiments of this application (a schematic diagram of a cross section in the AA' direction);

[0081] Figure 2b Based on Figure 2a The diagram shows a top view of the microelectromechanical device (MEMS) structure, including an "I"-shaped vent.

[0082] Figure 3a A schematic diagram of a third structure of the microelectromechanical device provided in the embodiments of this application (a schematic cross-section diagram in the AA' direction);

[0083] Figure 3b Based on Figure 3a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air outlet.

[0084] Figure 3c Based on Figure 3a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air inlet.

[0085] Figure 3dFor based on Figure 3a The diagram shows a top view of the microelectromechanical device (MEMS) structure, including an "I"-shaped vent.

[0086] Figure 4 This is a first schematic diagram illustrating the working principle of the microelectromechanical device provided in the embodiments of this application;

[0087] Figure 5 This is a second schematic diagram illustrating the working principle of the microelectromechanical device provided in the embodiments of this application;

[0088] Figure 6 A schematic diagram of the fourth structure of the microelectromechanical device provided in the embodiments of this application (a schematic diagram of the cross section in the AA' direction);

[0089] Figure 7 A schematic diagram of the fifth structure of the microelectromechanical device provided in the embodiments of this application (a schematic diagram of the cross section in the AA' direction);

[0090] Figure 8a A sixth structural schematic diagram (AA' direction cross-sectional schematic diagram) of the microelectromechanical device provided in the embodiments of this application;

[0091] Figure 8b For based on Figure 8a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air outlet.

[0092] Figure 8c For based on Figure 8a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air inlet.

[0093] Figure 9a A seventh structural schematic diagram (AA' direction cross-sectional schematic diagram) of the microelectromechanical device provided in the embodiments of this application;

[0094] Figure 9b For based on Figure 9a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air outlet.

[0095] Figure 9c For based on Figure 9a The microelectromechanical device structure shown is a top view schematic diagram from the perspective of the air inlet cover.

[0096] Figure 9d For based on Figure 9a The diagram shown is a side view of the microelectromechanical device structure from the perspective of the air inlet.

[0097] Figure 10a A schematic diagram of the eighth structure of the microelectromechanical device provided in the embodiments of this application (a schematic diagram of the cross section in the AA' direction);

[0098] Figure 10b For based on Figure 10a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air outlet.

[0099] Figure 10c For based on Figure 10a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air inlet.

[0100] Figure 10d For based on Figure 10a The diagram shows a top view of a microelectromechanical device (MEMS) structure with a bracket-shaped vent.

[0101] Figure 11 A ninth structural schematic diagram (AA' direction cross-sectional schematic diagram) of the microelectromechanical device provided in the embodiments of this application;

[0102] Figure 12a This is a schematic diagram of a first process for fabricating a microelectromechanical device according to an embodiment of this application;

[0103] Figure 12b This is a schematic diagram of a second process for fabricating microelectromechanical devices provided in the embodiments of this application;

[0104] Figure 13a This is a first schematic diagram of the process of fabricating a piezoelectric actuation structure;

[0105] Figure 13b A second schematic diagram of the process of fabricating a piezoelectric actuation structure;

[0106] Figure 13c A third schematic diagram of the process of fabricating a piezoelectric actuation structure;

[0107] Figure 13d The fourth schematic diagram in the process of fabricating a piezoelectric actuation structure;

[0108] Figure 13e The fifth schematic diagram in the process of fabricating a piezoelectric actuation structure;

[0109] Figure 13f The sixth schematic diagram in the process of fabricating a piezoelectric actuation structure;

[0110] Figure 14a This is a first schematic diagram of the process of preparing the air inlet cover.

[0111] Figure 14b This is a second schematic diagram of the process of preparing the air inlet cover;

[0112] Figure 14c This is a third schematic diagram of the process of preparing the air inlet cover.

[0113] Figure 14dThis is the fourth schematic diagram in the process of preparing the air inlet cover;

[0114] Figure 15a This is a first schematic diagram of the process of preparing the vent cover plate;

[0115] Figure 15b This is a second schematic diagram of the process of preparing the vent cover plate;

[0116] Figure 15c This is a third schematic diagram of the process of preparing the vent cover;

[0117] Figure 15d This is the fourth schematic diagram in the process of preparing the vent cover;

[0118] Figure 16 A schematic diagram of the structure of an electronic device provided in this application embodiment. Detailed Implementation

[0119] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0120] Traditional integrated circuit heat sinks mainly consist of components such as fans, heat sink fins, and heat pipes. The fan generates airflow, the heat sink fins increase the heat dissipation area, and the heat pipes transfer heat from the integrated circuit to the heat sink fins, which is then dissipated by the fan. However, when these integrated circuit heat sinks are operating, the fans generate significant noise, affecting the user experience.

[0121] To address the aforementioned issues, this application provides a microelectromechanical device (MEMS), a method for fabricating a MEMS, and an electronic device.

[0122] Next, the microelectromechanical device 1 provided in the embodiments of this application will be described in detail. The microelectromechanical device 1 includes:

[0123] The piezoelectric actuation structure 11 and the cover plate structure 12 are provided. The piezoelectric actuation structure 11 includes a substrate 111 and a piezoelectric actuation unit 112. The piezoelectric actuation unit 112 is disposed on one side of the substrate 111, and the cover plate structure 12 is connected to the substrate 111. A cavity is formed between the cover plate structure 12 and the substrate 111, and the piezoelectric actuation unit 112 is located in the cavity. The piezoelectric actuation unit 112 is used to generate vibration under the excitation of an electrical signal.

[0124] The piezoelectric actuator 112 has both piezoelectric effect and inverse piezoelectric effect. The piezoelectric effect refers to the generation of an electric field inside a piezoelectric material when it is subjected to mechanical stress. The piezoelectric effect enables the piezoelectric material to convert mechanical energy into electrical energy, and vice versa. That is, the inverse piezoelectric effect. When an electric field is applied in the polarization direction of the piezoelectric material, mechanical deformation or mechanical stress will be generated. When the external electric field is removed, the deformation or stress will also disappear. The inverse piezoelectric effect enables the piezoelectric material to convert electrical energy into mechanical energy.

[0125] In this embodiment, a piezoelectric actuation unit 112 is provided, and heat dissipation is achieved by utilizing the vibration of the piezoelectric actuation unit 112. Compared with the use of fans for heat dissipation in related technologies, this reduces operating noise and improves the user experience. In addition, it can reduce the size and weight of the device and increase its application rate.

[0126] In one possible implementation, the microelectromechanical device 1 includes:

[0127] The piezoelectric actuation structure 11 and the cover plate structure 12; the piezoelectric actuation structure 11 includes a substrate 111 and a piezoelectric actuation unit 112;

[0128] The piezoelectric actuation unit 112 is disposed on one side of the substrate 111, and the cover plate structure 12 is connected to the substrate 111;

[0129] A cavity is formed between the cover plate structure 12 and the substrate 111, and the piezoelectric actuation unit 112 is located inside the cavity;

[0130] Substrate 111 is a semiconductor material substrate, or substrate 111 is a glass-based material substrate;

[0131] Cover structure 12 is a semiconductor material cover structure;

[0132] The width of the microelectromechanical device 1 ranges from 1,000 micrometers to 5,000 micrometers, the length of the microelectromechanical device 1 ranges from 1,000 micrometers to 5,000 micrometers, and the thickness of the microelectromechanical device 1 ranges from 640 micrometers to 1,080 micrometers, or the thickness of the microelectromechanical device 1 ranges from 343 micrometers to 860 micrometers.

[0133] The semiconductor material mentioned above can be Si (silicon), SiGe (silicon germanium), Ge (germanium) wafer, or other semiconductor materials that meet the requirements. This application does not specifically limit the specific semiconductor material.

[0134] Compared to semiconductor substrates 111, glass substrates 111 can further reduce costs while meeting the requirements.

[0135] In this embodiment, the substrate 111 of the piezoelectric actuation structure 11 is made of semiconductor material / glass substrate material, and the cover plate structure 12 is made of semiconductor material. This can be matched with MEMS process (Micro-Electro-Mechanical Systems, which refers to the process of manufacturing micro-electro-mechanical system devices based on semiconductor technology, from nanometer scale to millimeter scale microstructure processing technology), to realize micro-electro-mechanical device 1 with micrometer-scale to millimeter-scale structural size, with a smaller footprint, so that the micro-electro-mechanical device 1 can be applied to smaller and thinner electronic devices.

[0136] In one possible implementation, the piezoelectric actuation unit 112 includes an etch stop layer 21, a first passivation layer 22, a first electrode layer (bottom electrode layer) 23, a piezoelectric layer 24, a second passivation layer 25, and a second electrode layer (top electrode layer) 26.

[0137] An etch stop layer 21 is disposed on a substrate 111, a first passivation layer 22 is disposed on the side of the etch stop layer 21 away from the substrate 111, a first electrode layer 23 is disposed on the side of the first passivation layer 22 away from the substrate 111, a piezoelectric layer 24 is disposed on the side of the first electrode layer 23 away from the substrate 111, a second passivation layer 25 is disposed on the side of the piezoelectric layer 24 away from the substrate 111, and a second electrode layer 26 is disposed on the side of the second passivation layer 25 away from the substrate 111.

[0138] The etching stop layer 21 is made of Mo (molybdenum), the first passivation layer 22 is made of SiNx (silicon nitride) or SiO2 (silicon dioxide), the first electrode layer (bottom electrode layer) 23 is made of Cu (copper) or Ti (titanium), the second passivation layer 25 is made of SiNx or SiO2, and the second electrode layer (top electrode layer) 26 is made of Cu or Ti.

[0139] The material of the piezoelectric layer 24 can be PZT (Lead Zirconium Titanate), or AlN (Aluminum Nitride), ZnO (Zinc O), AlScN (Aluminum Scandium Nitride), etc. This application does not specifically limit it.

[0140] In one possible implementation, the thickness of the etch stop layer 21 is 0.2 micrometers, the thickness of the first passivation layer 22 is 0.2 micrometers, the thickness of the first electrode layer 23 ranges from 0.01 micrometers to 1 micrometer, the thickness of the piezoelectric layer 24 ranges from 2 micrometers to 50 micrometers, the thickness of the second passivation layer 25 is 0.2 micrometers, and the thickness of the second electrode layer 26 ranges from 0.01 micrometers to 1 micrometer.

[0141] In one possible implementation, see [link to relevant documentation]. Figure 1 The cover structure 12 includes an air inlet cover 121 and an air outlet cover 122.

[0142] The air inlet cover 121 is disposed on one side of the substrate 111, and the air outlet cover 122 is disposed on the other side of the substrate 111.

[0143] The air inlet cover 121 includes a first protective part 1211 and a first edge annular protrusion 1212. The first edge annular protrusion 1212 of the air inlet cover 121 is bonded to the edge of the substrate 111.

[0144] A first cavity 13 is formed between the air inlet cover 121 and the substrate 111; the piezoelectric actuation unit 112 is located in the first cavity 13;

[0145] The vent cover 122 includes a second protective portion 1221 and a second edge annular protrusion 1222. The second edge annular protrusion 1222 of the vent cover 122 is bonded to the edge of the substrate 111.

[0146] A second cavity 14 is formed between the vent cover 122 and the substrate 111;

[0147] The second protective part 1221 is provided with at least one air outlet 12211 that penetrates the second protective part 1221, and the multiple air outlets 12211 are arranged in an array on the orthographic projection of the substrate plane.

[0148] The thickness of the first edge annular protrusion 1212 ranges from 200 micrometers to 400 micrometers, the thickness of the second edge annular protrusion 1222 ranges from 200 micrometers to 400 micrometers, the thickness of the first protective part 1211 is 100 micrometers, and the thickness of the second protective part 1221 is 100 micrometers.

[0149] The second protection unit 1221 may be provided with multiple uniformly arrayed air outlets 12211. The air outlets 12211 can be arranged evenly and reasonably. This application does not specify the number of air outlets 12211.

[0150] In one possible implementation, the orthographic projection of the vent 12211 onto the substrate plane is circular;

[0151] The diameter of a circle ranges from 30 micrometers to 150 micrometers.

[0152] Understandable Figure 1 A schematic diagram of the first structure of the microelectromechanical device provided in the embodiments of this application (a schematic diagram of the cross section in the AA' direction).

[0153] In one possible implementation, see [link to relevant documentation]. Figure 2a and Figure 2b ,based on Figure 1 The microelectromechanical device structure shown has a vent 1111 that penetrates the middle of the substrate 111;

[0154] In the length direction of the micro electro-mechanical device 1, the orthographic projection of the vent hole 1111 on the plane of the second protection part is in the shape of a Chinese character '工'.

[0155] The piezoelectric actuator unit 112 includes a first sub-unit 1121 and a second sub-unit 1122. The orthographic projection of the first sub-unit 1121 on the substrate plane is arranged in one opening of the '工'-shaped vent hole 1111, and the orthographic projection of the second sub-unit 1122 on the substrate plane is arranged in the other opening of the '工'-shaped vent hole 1111.

[0156] Among them, the length range of the first sub-unit 1121 is from 135 microns to 675 microns, and the width range of the first sub-unit 1121 is from 135 microns to 675 microns; the length range of the second sub-unit 1122 is from 135 microns to 675 microns, and the width range of the second sub-unit 1122 is from 135 microns to 675 microns; the length range of the vent hole 1111 is from 495 microns to 2475 microns, the width range of the vent hole 1111 is from 580 microns to 3300 microns, and the width range of the central area of the vent hole 1111 is from 40 microns to 200 microns.

[0157] It should be noted that the length direction, width direction, and thickness direction of the micro electro-mechanical device 1 have been marked in the attached drawings. The length direction can be understood as the Y direction (front-back direction) in the three-dimensional coordinate system, and the dimension in the length direction is the length dimension. The width direction can be understood as the X direction (left-right direction) in the three-dimensional coordinate system, and the dimension in the width direction is the width dimension. The thickness direction can be understood as the Z direction (up-down direction) in the three-dimensional coordinate system, and the dimension in the thickness direction is the thickness dimension.

[0158] In the length direction of the micro electro-mechanical device 1, the two '-' shaped parts of the '工'-shaped vent hole 1111 are used to assist the vibration of the piezoelectric actuator unit 112, and the '|' shaped part of the '工'-shaped vent hole 1111 is used for ventilation.

[0159] It should be noted that the width of the '工'-shaped vent hole 1111 refers to the width of the '-' shaped part, and the width of the central area of the '工'-shaped vent hole 1111 refers to the width of the '|' shaped part (the position of the central area of the '工'-shaped vent hole 1111 has been marked in Figure 2b and Figure 3d .

[0160] It can be understood that Figure 2a This is the second structural schematic diagram (sectional schematic diagram in the AA' direction) of the micro electro-mechanical device provided by the embodiment of the present application. Figure 2b is a top view schematic diagram of the '工'-shaped vent hole based on the structure of the micro electro-mechanical device shown in Figure 2a .

[0161] In one possible implementation, see [link to relevant documentation]. Figure 3a ,based on Figure 2a The microelectromechanical device structure shown has an air inlet 12111 that penetrates the first protective part 1211 of the air inlet cover 121.

[0162] The orthographic projections of the air inlet 12111 and the air outlet 12211 on the substrate plane do not overlap.

[0163] In one possible implementation, the orthographic projection of the air inlet 12111 onto the substrate plane is rectangular;

[0164] The width of the air inlet 12111 ranges from 40 micrometers to 200 micrometers, and the length of the air inlet 12111 ranges from 800 micrometers to 4000 micrometers.

[0165] Understandable Figure 3a This is a schematic diagram (AA' direction cross-sectional view) of a third structure of the microelectromechanical device provided in the embodiments of this application. It is understood that... Figure 3b For based on Figure 3a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air outlet. Figure 3b The orthographic projection of the air outlet 12211 onto the substrate plane is shown as a circle. It can be understood that... Figure 3c For based on Figure 3a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air inlet. Figure 3c The diagram is illustrated by the rectangular projection of the air inlet 12111 onto the substrate plane. Figure 3d For based on Figure 3a The diagram shows a top view of the microelectromechanical device structure, specifically the "I"-shaped vent 1111.

[0166] based on Figure 3a The microelectromechanical device (MEMS) structure shown illustrates the heat dissipation working principle of the MEMS 1 provided in this application. (See also...) Figure 4 and Figure 5 The microelectromechanical device 1 is connected to the heat sink copper sheet via an adhesive layer (which can be a polymer material, glass material, or metal, etc.). Utilizing the inverse piezoelectric effect of the piezoelectric material, under electrical signal excitation, the first subunit 1121 and the second subunit 1122 generate periodic vibrations in the same or opposite directions (vibration frequency 15kHz-30kHz), driving the surrounding air circulation to carry away heat and achieve a heat dissipation effect. The airflow trajectory is as follows... Figure 4 , Figure 5 As indicated by the middle arrow. This is understandable. Figure 5The heat dissipation copper sheet shown can be applied to any of the microelectromechanical devices 1 provided in the embodiments of this application.

[0167] In one possible implementation, see [link to relevant documentation]. Figure 6 ,based on Figure 3a The microelectromechanical device structure shown has a first concave region 1112 and a second concave region 1113 on the side of the substrate 111 facing the vent cover 122;

[0168] The orthographic projection of the first subunit 1121 onto the substrate plane is included in the first concave region 1112, and the orthographic projection of the second subunit 1122 onto the substrate plane is included in the second concave region 1113.

[0169] Understandable Figure 6 A schematic diagram of the fourth structure of the microelectromechanical device provided in the embodiments of this application (a schematic diagram of the cross section in the AA' direction).

[0170] In this embodiment of the application, compared to Figure 3a The microelectromechanical device structure shown is Figure 6 The substrate of the microelectromechanical device shown is etched with a concave region (groove) at the bottom, which can increase the volume of the second cavity 14, improve the backflow problem, and enhance the fluid pulse.

[0171] In one possible implementation, see [link to relevant documentation]. Figure 7 ,based on Figure 6 The microelectromechanical device structure shown includes a central protrusion 1223 in the outlet cover plate 122.

[0172] The central protrusion 1223 and the second edge annular protrusion 1222 are located on the same side of the second protective part 1221;

[0173] The width of the central protrusion 1223 is smaller than the width of the central area of ​​the vent 1111;

[0174] The length of the central protrusion 1223 is greater than or equal to the length of the vent 1111;

[0175] The thickness of the central protrusion 1223 is greater than or equal to 0.9 times the thickness of the second edge annular protrusion 1222, and less than or equal to the thickness of the second edge annular protrusion 1222.

[0176] Understandable Figure 7 This is a schematic diagram of the fifth structure of the microelectromechanical device provided in the embodiments of this application (a schematic diagram of the cross section in the AA' direction).

[0177] In this embodiment of the application, compared to Figure 6 The microelectromechanical device structure shown is Figure 7The air outlet cover 122 of the microelectromechanical device shown has a central protrusion (baffle) 1223 etched out. When the piezoelectric actuation unit 112 vibrates downward to form a fluid pulse, the substrate 111 and the central protrusion 1223 form a relatively closed space, which can further improve the problem of backflow of air and enhance the fluid pulse.

[0178] In one possible implementation, see [link to relevant documentation]. Figure 8a ,based on Figure 2a The microelectromechanical device structure shown has a first air inlet 1211 through the first protective part 1211 of the air inlet cover 121, and a second air inlet 12113 through the first protective part 1211.

[0179] The first air inlet 12112 and the first sub-unit 1121 have overlapping portions in their orthographic projections on the substrate plane, and the second air inlet 12113 and the second sub-unit 1122 have overlapping portions in their orthographic projections on the substrate plane.

[0180] A first concave region 1112 and a second concave region 1113 are provided on the side of the substrate 111 facing the air outlet cover plate 122;

[0181] The orthographic projection of the first subunit 1121 onto the substrate plane is included in the first concave region 1112, and the orthographic projection of the second subunit 1122 onto the substrate plane is included in the second concave region 1113.

[0182] The vent cover 122 also includes a central protrusion 1223;

[0183] The central protrusion 1223 and the second edge annular protrusion 1222 are located on the same side of the second protective part 1221;

[0184] The width of the central protrusion 1223 is smaller than the width of the central area of ​​the vent 1111;

[0185] The length of the central protrusion 1223 is greater than or equal to the length of the vent 1111;

[0186] The thickness of the central protrusion 1223 is greater than or equal to 0.9 times the thickness of the second edge annular protrusion 1222, and less than or equal to the thickness of the second edge annular protrusion 1222.

[0187] In one possible implementation, the orthographic projection of the first air inlet 12112 onto the substrate plane is a rectangle, and the orthographic projection of the second air inlet 12113 onto the substrate plane is a rectangle.

[0188] The width of the first air inlet 12112 ranges from 40 micrometers to 200 micrometers, and the length of the first air inlet 12112 ranges from 800 micrometers to 4000 micrometers. The width of the second air inlet 12113 ranges from 40 micrometers to 200 micrometers, and the length of the second air inlet 12113 ranges from 800 micrometers to 4000 micrometers.

[0189] Understandable Figure 8a This is a schematic diagram (AA' direction cross-sectional view) of a sixth structure of a microelectromechanical device provided in the embodiments of this application. It is understood that... Figure 8b For based on Figure 8a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air outlet. Figure 8b The orthographic projection of the air outlet 12211 onto the substrate plane is shown as a circle. It can be understood that... Figure 8c For based on Figure 8a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air inlet. Figure 8c The first air inlet 12112 and the second air inlet 12113 are shown as rectangles on the substrate plane.

[0190] In this embodiment of the application, compared to Figure 7 The microelectromechanical device structure shown is Figure 8a The air inlets of the microelectromechanical device shown are located on both sides of the top, that is... Figure 7 The air inlet in the middle of the top of the central air inlet cover 121 is changed to air inlets distributed on both sides of the top, which are staggered from the vent 1111. This can further improve the problem of backflow of air and enhance fluid pulse.

[0191] In one possible implementation, see [link to relevant documentation]. Figure 9a ,based on Figure 2a The microelectromechanical device structure shown has a first air inlet 12112 and a second air inlet 12113 through the first edge annular protrusion 1212 of the air inlet cover 121 in the width direction of the microelectromechanical device 1.

[0192] The first air inlet 12112 is located close to the first sub-unit 1121, and the second air inlet 12113 is located close to the second sub-unit 1122;

[0193] A first concave region 1112 and a second concave region 1113 are provided on the side of the substrate 111 facing the air outlet cover plate 122;

[0194] The orthographic projection of the first subunit 1121 onto the substrate plane is included in the first concave region 1112, and the orthographic projection of the second subunit 1122 onto the substrate plane is included in the second concave region 1113.

[0195] The vent cover 122 also includes a central protrusion 1223;

[0196] The central protrusion 1223 and the second edge annular protrusion 1222 are located on the same side of the second protective part 1221;

[0197] The width of the central protrusion 1223 is smaller than the width of the central area of ​​the vent 1111;

[0198] The length of the central protrusion 1223 is greater than or equal to the length of the vent 1111;

[0199] The thickness of the central protrusion 1223 is greater than or equal to 0.9 times the thickness of the second edge annular protrusion 1222, and less than or equal to the thickness of the second edge annular protrusion 1222.

[0200] Understandable Figure 9a This is a schematic diagram (AA' direction cross-sectional view) of the seventh structure of the microelectromechanical device provided in the embodiments of this application. It is understood that... Figure 9b For based on Figure 9a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air outlet. Figure 9b The orthographic projection of the air outlet 12211 onto the substrate plane is shown as a circle. It can be understood that... Figure 9c For based on Figure 9a The diagram shown is a top view of the microelectromechanical device (MEMS) structure from the perspective of the air inlet cover. Figure 9d For based on Figure 9a The diagram shown is a side view of the microelectromechanical device structure from the perspective of the air inlet.

[0201] In this embodiment of the application, compared to Figure 8a The microelectromechanical device structure shown is Figure 9a The air inlet of the microelectromechanical device shown is located on two side walls, that is... Figure 8a The air inlets that were originally located on both sides of the top of the air inlet cover 121 were replaced with two air inlets on the side walls, which were distributed at a 90-degree angle to the air outlet 12211. This can further improve the problem of airflow backflow and enhance fluid pulse.

[0202] In one possible implementation, see [link to relevant documentation]. Figure 10a ,based on Figure 1 The microelectromechanical device structure shown has a vent 1111 through the middle of the substrate 111.

[0203] Along the length of the microelectromechanical device 1, the orthographic projection of the vent 1111 onto the plane of the second protective part is in the shape of a square bracket [].

[0204] The piezoelectric actuation unit 112 includes a first subunit 1121 and a second subunit 1122. The orthographic projection of the first subunit 1121 on the substrate plane is arranged in one side opening of the bracket-shaped vent 1111, and the orthographic projection of the second subunit 1122 on the substrate plane is arranged in the other side opening of the bracket-shaped vent 1111.

[0205] An air inlet 12111 is provided in the middle of the first protective part 1211 of the air inlet cover 121;

[0206] The orthographic projections of the air inlet 12111 and the air outlet 12211 onto the substrate plane do not overlap.

[0207] A first concave region 1112 and a second concave region 1113 are provided on the side of the substrate 111 facing the air outlet cover plate 122;

[0208] The orthographic projection of the first subunit 1121 onto the substrate plane is included in the first concave region 1112, and the orthographic projection of the second subunit 1122 onto the substrate plane is included in the second concave region 1113.

[0209] The vent cover 122 also includes a central support protrusion 1224;

[0210] The central support protrusion 1224 and the second edge annular protrusion 1222 are located on the same side of the second protective part 1221;

[0211] The orthographic projection of the central support protrusion 1224 onto the substrate plane does not overlap with the first concave region 1112, and the orthographic projection of the central support protrusion 1224 onto the substrate plane does not overlap with the second concave region 1113.

[0212] The thickness of the central support protrusion 1224 is equal to the thickness of the second edge annular protrusion 1222.

[0213] In one possible implementation, the orthographic projection of the air inlet 12111 onto the substrate plane is rectangular;

[0214] The width of the air inlet 12111 ranges from 40 micrometers to 200 micrometers, and the length of the air inlet 12111 ranges from 800 micrometers to 4000 micrometers.

[0215] Understandable Figure 10a This is a schematic diagram (AA' direction cross-sectional view) of the eighth structure of the microelectromechanical device provided in the embodiments of this application. It is understood that... Figure 10b For based on Figure 10a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air outlet. Figure 10b The orthographic projection of the air outlet 12211 onto the substrate plane is shown as a circle. It can be understood that... Figure 10c For based on Figure 10a The diagram shown is a top view of the microelectromechanical device structure from the perspective of the air inlet. Figure 10c The diagram illustrates the air inlet 12111 as a rectangle projected onto the substrate plane. It is understood that... Figure 10d For based on Figure 10a The diagram shows a top view of a microelectromechanical device (MEMS) structure with a bracket-shaped vent.

[0216] In this embodiment of the application, compared to Figure 6 The microelectromechanical device structure shown is Figure 10a The microelectromechanical device structure shown, which resembles the central symmetry of butterfly wings, can effectively isolate the convection between the air inlet and outlet, further improving the problem of backflow and enhancing fluid pulse.

[0217] In one possible implementation, see [link to relevant documentation]. Figure 11 The cover structure 12 includes an air outlet cover 122;

[0218] The vent cover 122 includes a second protective portion 1221 and a second edge annular protrusion 1222. The second edge annular protrusion 1222 of the vent cover 122 is bonded to the edge of the substrate 111.

[0219] A second cavity 14 is formed between the vent cover 122 and the substrate 111; the piezoelectric actuation unit 112 is located inside the second cavity 14;

[0220] The second protective part 1221 is provided with at least one air outlet 12211 that penetrates the second protective part 1221, and the multiple air outlets 12211 are arranged in an array on the orthographic projection of the substrate plane.

[0221] An air inlet 12111 is provided in the middle of the substrate 111;

[0222] The orthographic projections of the air inlet 12111 and the air outlet 12211 onto the substrate plane do not overlap.

[0223] The piezoelectric actuation unit 112 includes a first subunit 1121 and a second subunit 1122. In the width direction of the microelectromechanical device 1, the first subunit 1121 is arranged on one side of the air inlet 12111 by its orthogonal projection on the substrate plane, and the second subunit 1122 is arranged on the other side of the air inlet 12111 by its orthogonal projection on the substrate plane.

[0224] The vent cover 122 also includes a central protrusion 1223;

[0225] The central protrusion 1223 and the second edge annular protrusion 1222 are located on the same side of the second protective part 1221;

[0226] The width of the central protrusion 1223 is smaller than the width of the air inlet 12111;

[0227] The length of the central protrusion 1223 is greater than or equal to the length of the air intake 12111;

[0228] The thickness of the central protrusion 1223 is greater than or equal to 0.5 times the thickness of the second edge annular protrusion 1222, and less than or equal to 0.8 times the thickness of the second edge annular protrusion 1222.

[0229] The thickness of the second edge annular protrusion 1222 ranges from 203 micrometers to 680 micrometers, and the thickness of the second protective part 1221 is 100 micrometers; the length of the first subunit 1121 ranges from 135 micrometers to 675 micrometers, and the width of the first subunit 1121 ranges from 135 micrometers to 675 micrometers; the length of the second subunit 1122 ranges from 135 micrometers to 675 micrometers, and the width of the second subunit 1122 ranges from 135 micrometers to 675 micrometers.

[0230] In one possible implementation, the orthographic projection of the air inlet 12111 onto the substrate plane is rectangular;

[0231] The width of the air inlet 12111 ranges from 40 micrometers to 200 micrometers, and the length of the air inlet 12111 ranges from 800 micrometers to 4000 micrometers.

[0232] In one possible implementation, the orthographic projection of the vent 12211 onto the substrate plane is circular;

[0233] The diameter of a circle ranges from 30 micrometers to 150 micrometers.

[0234] Understandable Figure 11 This is a ninth structural schematic diagram (AA' direction cross-sectional schematic diagram) of the microelectromechanical device provided in the embodiments of this application.

[0235] In this embodiment, no air inlet cover is provided, and the piezoelectric actuation unit 112 is inverted. While satisfying the heat dissipation function of the microelectromechanical device and improving airflow backflow, the manufacturing process of the heat dissipation module is reduced, simplifying the process flow and reducing costs.

[0236] In one possible implementation, the thickness of the substrate 111 ranges from 40 micrometers to 80 micrometers.

[0237] In one possible implementation, the width of the first cavity 13 ranges from 900 micrometers to 4900 micrometers, and the width of the second cavity 14 ranges from 900 micrometers to 4900 micrometers.

[0238] This application also provides a method for fabricating a microelectromechanical device 1, see [link to relevant documentation]. Figure 12a The method includes the following steps:

[0239] Step S101: Obtain the pre-prepared piezoelectric actuation structure 11; wherein, the piezoelectric actuation structure 11 includes a substrate 111 and a piezoelectric actuation unit 112, and the piezoelectric actuation unit 112 is disposed on one side of the substrate 111.

[0240] Step S102: Obtain the pre-prepared cover plate structure 12;

[0241] Step S103: Connect the cover plate structure 12 to the substrate 111 to obtain the microelectromechanical device 1; wherein, a cavity is formed between the cover plate structure 12 and the substrate 111, and the piezoelectric actuation unit 112 is located in the cavity.

[0242] The specific analysis is the same as above, so it will not be repeated here.

[0243] In this embodiment, a piezoelectric actuation unit 112 is provided, and heat dissipation is achieved by utilizing the vibration of the piezoelectric actuation unit 112. Compared with the use of fans for heat dissipation in related technologies, this reduces operating noise and improves the user experience. In addition, it can reduce the size and weight of the device and increase its application rate.

[0244] In one possible implementation, see Figure 12b , Figure 12b A second flowchart illustrating the fabrication method of the microelectromechanical device 1 provided in this application embodiment includes the following steps:

[0245] Step S1201: Obtain the pre-prepared piezoelectric actuation structure 11; wherein, the piezoelectric actuation structure 11 includes a substrate 111 and a piezoelectric actuation unit 112, the piezoelectric actuation unit 112 is disposed on one side of the substrate 111, the substrate 111 is a semiconductor material substrate, or the substrate 111 is a glass-based material substrate.

[0246] Step S1202: Obtain the pre-prepared cover plate structure 12; wherein, the cover plate structure 12 is a semiconductor material cover plate structure;

[0247] Step S1203: Connect the cover plate structure 12 to the substrate 111 to obtain the microelectromechanical device 1; wherein, a cavity is formed between the cover plate structure 12 and the substrate 111, and the piezoelectric actuation unit 112 is located in the cavity;

[0248] The width of the microelectromechanical device 1 ranges from 1,000 micrometers to 5,000 micrometers, the length of the microelectromechanical device 1 ranges from 1,000 micrometers to 5,000 micrometers, and the thickness of the microelectromechanical device 1 ranges from 640 micrometers to 1,080 micrometers, or the thickness of the microelectromechanical device 1 ranges from 343 micrometers to 860 micrometers.

[0249] The specific analysis is the same as above, so it will not be repeated here.

[0250] In this embodiment, the substrate 111 of the piezoelectric actuation structure 11 is made of semiconductor material / glass-based material, and the cover plate structure 12 is made of semiconductor material. It can be matched with MEMS process to realize micro-electromechanical devices 1 with micron-level structure size to millimeter-level structure size, and the space occupied is further reduced, so that the micro-electromechanical device 1 can be applied to smaller and thinner electronic devices.

[0251] In one possible implementation, the piezoelectric actuation structure 11 is fabricated as follows:

[0252] See Figure 13a A stop layer 21 is sputtered onto the substrate 111.

[0253] See Figure 13b A first passivation layer 22 and a first electrode layer 23 are sequentially deposited on the etching stop layer 21.

[0254] See Figure 13c A piezoelectric layer 24 is deposited on the first electrode layer 23.

[0255] See Figure 13d A second passivation layer 25 and a second electrode layer 26 are sequentially deposited on the piezoelectric layer 24.

[0256] See Figure 13e After the backplane thinning is completed on the back side of substrate 111, the substrate hole etching is completed using a mask.

[0257] See Figure 13f The front film layer is patterned to obtain the first subunit 1121 and the second subunit 1122, thus completing the fabrication of the piezoelectric actuation structure 11.

[0258] In one possible implementation, the preparation process of the air inlet cover 121 is as follows:

[0259] See Figure 14a Photolithography and etching processes are performed on the first substrate 31, and a groove is formed on one side of the first substrate 31. The material of the first substrate 31 is a semiconductor material, such as Si, SiGe, Ge wafers, etc.

[0260] See Figure 14b The first substrate 31 uses a first photoresist pattern 32 as a mask on the groove side.

[0261] See Figure 14c An etching process is performed to form an air inlet at the center of the first substrate 31.

[0262] See Figure 14d Remove the first photoresist pattern 32 to obtain the air inlet cover 121.

[0263] In one possible implementation, the preparation process of the vent cover 122 is as follows:

[0264] See Figure 15a Photolithography and etching processes are performed on the second substrate 41, and a groove is formed on one side of the second substrate 41. The material of the second substrate 41 is a semiconductor material, such as Si, SiGe, Ge wafers, etc.

[0265] See Figure 15b The second substrate 41 uses a second photoresist pattern 42 as a mask on the groove side.

[0266] See Figure 15c An etching process is performed to form an vent in the second substrate 41.

[0267] See Figure 15d Remove the second photoresist pattern 42 to obtain the vent cover 122.

[0268] This application also provides an electronic device 5, see [link to previous document]. Figure 16 The electronic device 5 includes a flexible circuit board (FPC), multiple ground lines (GND) arranged along the row direction, multiple AC voltage signal lines (VAC) arranged along the column direction, and multiple microelectromechanical devices (MEMS) 1 as described in the above embodiments.

[0269] Each MEMS 1 in the Nth row of MEMS is electrically connected to the Nth ground line GND, and each MEMS 1 in the Mth column of MEMS is electrically connected to the Mth AC voltage signal line VAC; where N is an integer greater than or equal to 1, and M is an integer greater than or equal to 1.

[0270] The ground wire GND is electrically connected to the flexible circuit board FPC, and the AC voltage signal line VAC is electrically connected to the flexible circuit board FPC; the flexible circuit board FPC is used to drive the ground wire GND and the AC voltage signal line VAC respectively.

[0271] Electronic device 5 can be a thin and light laptop, a tablet computer, or a smartphone, etc. This application does not specifically limit it.

[0272] With the continuous miniaturization and integration of electronic devices, the requirements for heat dissipation performance of electronic devices are also increasing. The microelectromechanical device 1 provided in this application has the advantages of low noise, small size, light weight, low power consumption and high heat dissipation efficiency, and has broad application prospects in small electronic devices.

[0273] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0274] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0275] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A microelectromechanical device, characterized by include: A piezoelectric actuation structure and a cover plate structure; the piezoelectric actuation structure includes a substrate and a piezoelectric actuation unit; The piezoelectric actuation unit is disposed on one side of the substrate, and the cover plate structure is connected to the substrate; A cavity is formed between the cover plate structure and the substrate, and the piezoelectric actuation unit is located inside the cavity; The piezoelectric actuator is used to generate vibration under electrical signal excitation.

2. The microelectromechanical device of claim 1, wherein The piezoelectric actuation unit includes an etch stop layer, a first passivation layer, a first electrode layer, a piezoelectric layer, a second passivation layer, and a second electrode layer; The etching stop layer is disposed on the substrate, the first passivation layer is disposed on the side of the etching stop layer away from the substrate, the first electrode layer is disposed on the side of the first passivation layer away from the substrate, the piezoelectric layer is disposed on the side of the first electrode layer away from the substrate, the second passivation layer is disposed on the side of the piezoelectric layer away from the substrate, and the second electrode layer is disposed on the side of the second passivation layer away from the substrate.

3. The microelectromechanical device of claim 2, wherein The cover plate structure includes an air inlet cover plate and an air outlet cover plate; The air inlet cover is disposed on one side of the substrate, and the air outlet cover is disposed on the other side of the substrate; The air inlet cover includes a first protective part and a first edge annular protrusion, and the first edge annular protrusion of the air inlet cover is bonded to the edge of the substrate. A first cavity is formed between the air inlet cover and the substrate; the piezoelectric actuation unit is located within the first cavity; The vent cover plate includes a second protective part and a second edge annular protrusion, and the second edge annular protrusion of the vent cover plate is bonded to the edge of the substrate; A second cavity is formed between the air outlet cover and the substrate; The second protective part is provided with at least one air outlet that penetrates the second protective part, and the multiple air outlets are arranged in an array on the orthographic projection of the substrate plane.

4. The microelectromechanical device according to claim 3, characterized in that, The orthographic projection of the air outlet onto the substrate plane is circular.

5. The microelectromechanical device according to claim 3, characterized in that, A vent is provided in the middle of the substrate, penetrating the substrate; Along the length of the microelectromechanical device, the orthographic projection of the vent on the plane of the second protective part is in the shape of an "I". The piezoelectric actuation unit includes a first subunit and a second subunit. The first subunit is arranged in the orthographic projection on the substrate plane within one side opening of the "I"-shaped vent, and the second subunit is arranged in the orthographic projection on the substrate plane within the other side opening of the "I"-shaped vent.

6. The microelectromechanical device according to claim 5, characterized in that, An air inlet penetrating the first protective part is provided in the middle of the first protective part of the air inlet cover plate; The air inlet and the air outlet have no overlapping portions when projected onto the substrate plane.

7. The microelectromechanical device according to claim 6, characterized in that, The substrate has a first concave region and a second concave region on the side facing the air outlet cover; The orthographic projection of the first sub-unit onto the substrate plane is included in the first concave region, and the orthographic projection of the second sub-unit onto the substrate plane is included in the second concave region.

8. The microelectromechanical device according to claim 5, characterized in that, The first protective portion of the air inlet cover is provided with a first air inlet penetrating the first protective portion and a second air inlet penetrating the first protective portion. The first air inlet and the orthographic projection of the first subunit on the substrate plane have an overlapping portion, and the second air inlet and the orthographic projection of the second subunit on the substrate plane have an overlapping portion; The substrate has a first concave region and a second concave region on the side facing the air outlet cover; The orthographic projection of the first sub-unit onto the substrate plane is included in the first concave region, and the orthographic projection of the second sub-unit onto the substrate plane is included in the second concave region.

9. The microelectromechanical device according to claim 5, characterized in that, In the width direction of the microelectromechanical device, the first edge annular protrusion of the air inlet cover is provided with a first air inlet penetrating the first edge annular protrusion and a second air inlet penetrating the first edge annular protrusion. The first air inlet is located close to the first sub-unit, and the second air inlet is located close to the second sub-unit; The substrate has a first concave region and a second concave region on the side facing the air outlet cover; The orthographic projection of the first sub-unit onto the substrate plane is included in the first concave region, and the orthographic projection of the second sub-unit onto the substrate plane is included in the second concave region.

10. The microelectromechanical device according to claim 7, 8, or 9, characterized in that, The air outlet cover also includes a central protrusion; The central protrusion and the second edge annular protrusion are located on the same side of the second protective part; The width of the central protrusion is smaller than the width of the central area of ​​the vent. The length of the central protrusion is greater than or equal to the length of the vent. The thickness of the central protrusion is greater than or equal to 0.9 times the thickness of the second edge annular protrusion, and less than or equal to the thickness of the second edge annular protrusion.

11. The microelectromechanical device according to claim 3, characterized in that, A vent is provided in the middle of the substrate, penetrating the substrate; Along the length of the microelectromechanical device, the orthographic projection of the vent onto the plane of the second protective part is in the shape of a "square bracket"; The piezoelectric actuation unit includes a first subunit and a second subunit. The first subunit is arranged in the orthographic projection on the substrate plane within one side opening of the "bracket"-shaped vent, and the second subunit is arranged in the orthographic projection on the substrate plane within the other side opening of the "bracket"-shaped vent. An air inlet penetrating the first protective part is provided in the middle of the first protective part of the air inlet cover plate; The air inlet and the air outlet have no overlapping portions when projected onto the substrate plane; The substrate has a first concave region and a second concave region on the side facing the air outlet cover; The orthographic projection of the first sub-unit onto the substrate plane is included within the first concave region, and the orthographic projection of the second sub-unit onto the substrate plane is included within the second concave region; The air outlet cover also includes a central support protrusion; The central support protrusion and the second edge annular protrusion are located on the same side of the second protective part; The orthographic projection of the central support protrusion on the substrate plane does not overlap with the first concave region, and the orthographic projection of the central support protrusion on the substrate plane does not overlap with the second concave region; The thickness of the central support protrusion is equal to the thickness of the second edge annular protrusion.

12. The microelectromechanical device according to claim 2, characterized in that, The cover structure includes an air outlet cover; The vent cover plate includes a second protective part and a second edge annular protrusion, and the second edge annular protrusion of the vent cover plate is bonded to the edge of the substrate; A second cavity is formed between the vent cover and the substrate; the piezoelectric actuation unit is located within the second cavity; The second protective part is provided with at least one air outlet that penetrates the second protective part, and the multiple air outlets are arranged in an array when projected onto the substrate plane; An air inlet penetrating the substrate is provided in the middle of the substrate; The air inlet and the air outlet have no overlapping portions when projected onto the substrate plane; The piezoelectric actuation unit includes a first subunit and a second subunit. In the width direction of the microelectromechanical device, the first subunit is arranged on one side of the air inlet by its orthographic projection on the substrate plane, and the second subunit is arranged on the other side of the air inlet by its orthographic projection on the substrate plane. The air outlet cover also includes a central protrusion; The central protrusion and the second edge annular protrusion are located on the same side of the second protective part; The width of the central protrusion is smaller than the width of the air inlet; The length of the central protrusion is greater than or equal to the length of the air inlet; The thickness of the central protrusion is greater than or equal to 0.5 times the thickness of the second edge annular protrusion, and less than or equal to 0.8 times the thickness of the second edge annular protrusion.

13. The microelectromechanical device according to claim 12, characterized in that, The orthographic projection of the air outlet onto the substrate plane is circular.

14. The microelectromechanical device according to claim 7, 11, or 12, characterized in that, The orthographic projection of the air inlet onto the substrate plane is rectangular.

15. The microelectromechanical device according to claim 8, characterized in that, The first air inlet's orthographic projection onto the substrate plane is a rectangle, and the second air inlet's orthographic projection onto the substrate plane is a rectangle.

16. The microelectromechanical device according to claim 1, characterized in that, The substrate is a semiconductor material substrate, or the substrate is a glass-based material substrate; The cover plate structure is a semiconductor material cover plate structure.

17. A method for fabricating a microelectromechanical device, characterized in that, include: A pre-prepared piezoelectric actuation structure is obtained; wherein the piezoelectric actuation structure includes a substrate and a piezoelectric actuation unit, and the piezoelectric actuation unit is disposed on one side of the substrate; Obtain the pre-prepared cover plate structure; The cover plate structure is connected to the substrate to obtain a microelectromechanical device (MEMS); wherein a cavity is formed between the cover plate structure and the substrate, and the piezoelectric actuation unit is located in the cavity.

18. An electronic device, characterized in that, The electronic device includes a flexible circuit board, multiple ground wires arranged along the row direction, multiple AC voltage signal lines arranged along the column direction, and multiple microelectromechanical devices as described in any one of claims 1-16 above. Each microelectromechanical device (MEMS) in the Nth row is electrically connected to the Nth ground line, and each MEMS in the Mth column is electrically connected to the Mth AC voltage signal line; where N is an integer greater than or equal to 1, and M is an integer greater than or equal to 1. The ground wire is electrically connected to the flexible circuit board, and the AC voltage signal line is electrically connected to the flexible circuit board; the flexible circuit board is used to drive the ground wire and the AC voltage signal line respectively.

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