Preparation method of micro-electro-mechanical sensor, micro-electro-mechanical sensor and electronic equipment

Abstract

The invention discloses a preparation method of a micro-electro-mechanical sensor, the micro-electro-mechanical sensor and electronic equipment. The preparation method comprises the steps that a slide glass, a functional device and an injection mold are provided, and a thin film is attached to the surface of a cavity of the injection mold; mounting the functional device on the first surface of the slide glass; the injection mold is attached to the first surface, a packaging substrate is formed through injection molding, the functional device is embedded in the packaging substrate, and a sound hole is formed in the injection molding process in the thickness direction of the packaging substrate; the injection mold and the thin film are removed; the slide glass is removed, wiring layers are formed on the two surfaces of the packaging substrate in the thickness direction, the two wiring layers located in the thickness direction of the packaging substrate are connected, and the wiring layers are connected with the functional device.

Description

Technical Field

[0001] The present invention relates to the field of micro-electromechanical technology, and more particularly to a method for preparing a micro-electromechanical sensor, a micro-electromechanical sensor, and an electronic device. Background Art

[0002] In related technologies, the substrates for microelectromechanical sensors can be fabricated using the RDL process. During this process, acoustic holes must be drilled into the substrate. Substrates are typically prepared in batches and then cut. However, conventional acoustic holes are typically drilled individually mechanically after the substrate is formed. This approach is not suitable for batch production.

[0003] Therefore, it is necessary to provide a new technical solution to solve the above technical problems. Summary of the Invention

[0004] An object of the present invention is to provide a new technical solution for a method for preparing a micro-electromechanical sensor.

[0005] According to a first aspect of the present invention, a method for preparing a micro-electromechanical sensor is provided. The method comprises:

[0006] A carrier chip, a functional device and an injection mold are provided, wherein a film is attached to the surface of the cavity of the injection mold;

[0007] Mounting the functional device on the first surface of the carrier;

[0008] attaching the injection mold to the first surface, forming a package substrate by injection molding, embedding the functional device in the package substrate, and forming a sound hole along the thickness direction of the package substrate during the injection molding process;

[0009] removing the injection mold and the film;

[0010] The carrier is removed and wiring layers are formed on two surfaces of the packaging substrate in the thickness direction, the two wiring layers located in the thickness direction of the packaging substrate are connected, and the wiring layers are connected to the functional devices.

[0011] Optionally, the two routing layers located in the thickness direction of the packaging substrate are connected through a metallized through-hole.

[0012] Optionally, the step of providing a carrier chip, a functional device and an injection mold, wherein a thin film is attached to the surface of the cavity of the injection mold, includes: providing a conductor element;

[0013] The step of mounting the functional device on the first surface of the carrier comprises: mounting the conductor element on the first surface of the carrier;

[0014] The step of attaching the injection mold to the first surface, forming a package substrate by injection molding, embedding the functional device in the package substrate, and forming a sound hole along the thickness direction of the package substrate during the injection molding process includes: embedding the conductor element in the package substrate;

[0015] The step of removing the carrier sheet and forming routing layers on two surfaces of the package substrate in a thickness direction, wherein the two routing layers located in the thickness direction of the package substrate are connected, and the routing layers are connected to the functional devices, comprises: removing the carrier sheet to expose the conductor element;

[0016] The two wiring layers located in the thickness direction of the packaging substrate are connected through the conductor element.

[0017] Optionally, after the step of embedding the conductor element in the packaging substrate, the method further comprises:

[0018] The surface of the packaging substrate facing away from the carrier is ground to expose one end of the conductive material.

[0019] Optionally, the carrier is removed and routing layers are formed on the two surfaces in the thickness direction of the packaging substrate, the two routing layers located in the thickness direction of the packaging substrate are connected, and in the step of connecting the routing layers to the functional devices, the two routing layers located in the thickness direction of the packaging substrate are respectively connected to the two ends of the conductor element.

[0020] Optionally, the step of attaching the injection mold to the first surface, forming a package substrate by injection molding, embedding the functional device in the package substrate, and forming an acoustic hole along the thickness direction of the package substrate during the injection molding process further includes:

[0021] A through hole is provided along the thickness direction of the packaging substrate;

[0022] A conductor element is formed in the through hole; wherein the two wiring layers located in the thickness direction of the packaging substrate are connected through the conductor element.

[0023] Optionally, forming the conductor element in the through hole includes: sputtering a seed layer on an inner wall of the through hole;

[0024] Conductor elements are formed in the through holes by electroplating or chemical plating.

[0025] Optionally, before the step of forming a conductor element in the through hole by electroplating or chemical plating, the method further includes:

[0026] The seed layer on the surface of the packaging substrate facing away from the carrier is removed.

[0027] Optionally, after the step of forming a conductor element in the through hole by electroplating or chemical plating, the method further includes:

[0028] A planarization process is performed on a side of the conductor element that is away from the packaging substrate.

[0029] Optionally, the through hole is formed by laser etching, plasma etching or mechanical drilling.

[0030] Optionally, forming a wiring layer on the two surfaces of the package substrate in the thickness direction after the carrier is removed and the package substrate is removed, connecting the two wiring layers in the thickness direction of the package substrate, and connecting the wiring layer to the functional device includes:

[0031] forming a wiring layer on one surface of the packaging substrate in a thickness direction;

[0032] forming a through hole along the thickness direction of the packaging substrate;

[0033] providing a metal layer on the inner wall of the through hole;

[0034] A wiring layer is formed on the other surface of the packaging substrate in the thickness direction, and two ends of the metal layer are respectively connected to the two wiring layers.

[0035] According to a second aspect of the present application, a micro-electromechanical sensor is provided. The micro-electromechanical sensor is manufactured according to the above-mentioned manufacturing method.

[0036] According to a third aspect of the present application, an electronic device is provided, which includes the above-mentioned micro-electromechanical sensor.

[0037] In an embodiment of the present application, the injection mold cavity is provided with a raised structure at the position corresponding to the acoustic hole. A thin film covers the raised structure, allowing the acoustic hole to be formed in one step during the injection molding process, eliminating the need for subsequent drilling of the package substrate. This production method effectively reduces the number of processing steps and achieves high dimensional accuracy and a stable shape for the acoustic hole. This production method is suitable for large-scale, batch production of microelectromechanical sensors.

[0038] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0040] Figure 1 4 is a flow chart of a method for preparing a micro-electromechanical sensor according to an embodiment of the present application.

[0041] Figures 2 to 8 Schematic diagram of a method for preparing a micro-electromechanical sensor according to an embodiment of the present application.

[0042] Figures 9 to 11 This is a process flow chart of the pre-deposited copper pillar method TMV according to an embodiment of the present application.

[0043] Figures 12 to 18 This is a process flow chart of the through-hole filling method TMV according to an embodiment of the present application.

[0044] Reference numerals:

[0045] 101. Carrier; 102. Adhesive film; 103. Functional device; 104. Package substrate; 105. First routing layer; 106. Second routing layer; 107. Acoustic via; 108. Copper pillar; 109. Through hole; 109a. Metallized through hole; 110. Seed layer. DETAILED DESCRIPTION

[0046] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0047] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0048] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0049] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0050] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0051] According to one embodiment of the present application, a method for preparing a micro-electromechanical sensor is provided. Figure 1 As shown, the preparation method comprises:

[0052] Provide a carrier wafer 101, a functional device 103, and an injection mold, wherein a film is attached to the surface of the cavity of the injection mold;

[0053] Mounting the functional device 103 on the first surface of the carrier 101;

[0054] The injection mold is attached to the first surface, and a package substrate 104 is formed by injection molding. The functional device 103 is embedded in the package substrate 104 , and an acoustic hole 107 is formed along the thickness direction of the package substrate 104 during the injection molding process.

[0055] removing the injection mold and the film;

[0056] The carrier film 101 is removed and wiring layers are formed on two surfaces of the packaging substrate 104 in the thickness direction. The two wiring layers located in the thickness direction of the packaging substrate 104 are connected, and the wiring layers are connected to the functional device 103 .

[0057] Specifically, if Figures 2 to 8 As shown, the carrier 101 is used to carry the functional device 103 for injection molding to form the packaging substrate 104. The material of the packaging substrate 104 is plastic. The material of the carrier 101 is glass, ceramic, silicon wafer, etc. The first surface is a flat surface. The functional device 103 is, for example, an active device, a passive device, etc. Active devices are, for example, diodes, transistors, integrated circuit chips, etc. Passive devices are, for example, capacitors, inductors, resistors, etc. The functional device 103 is connected to other components through electrical connection points such as pads. During mounting, the functional device 103 is adhered to the first surface. In order to achieve a good mounting effect, a glue layer is attached to the first surface. The glue layer is double-sided tape. The functional device 103 is adhered to the double-sided tape.

[0058] The injection mold is used to form the package substrate 104 by injection molding. The mold cavity has a raised structure corresponding to the shape of the acoustic hole 107 in the package substrate 104. A film is applied to the surface of the cavity and covers the raised structure. One or more layers of film are placed in the mold cavity. The film covers the mold cavity, and the edges of the film are fixed to the edges of the cavity to maintain the film's position. The film is typically made of a material with good light transmittance, heat resistance, and chemical resistance. Examples of film materials include polyester and polycarbonate. During the injection molding process, plastic is injected into the mold cavity. The presence of the film ensures that the plastic is evenly distributed within the mold cavity, avoiding air pockets or bubbles that occur with existing injection molding methods. The shape of the film matches the shape of the cavity, thus also helping to maintain the plastic's shape and prevent deformation. After the plastic cools and solidifies, the package substrate 104 is formed. The film and package substrate 104 are removed from the mold together. The presence of the film facilitates demolding and helps maintain the shape and dimensional accuracy of the package substrate 104.

[0059] After the injection molding is complete, the injection mold is removed and the film is removed together with it.

[0060] Next, the carrier 101 is removed by peeling off the adhesive film 102. The functional device 103 previously mounted on the carrier 101 is exposed on the surface of the package substrate 104 that is bonded to the carrier 101. For example, the adhesive film 102 is a heat release film. When the adhesive film 102 is removed, the heat release film is heated, which releases heat, thereby reducing the bonding strength between the heat release film and the carrier 101 and making the heat release film easier to peel off.

[0061] A first routing layer 105 and a second routing layer 106 are provided on either side of the package substrate 104. For example, a metal redistribution layer (RDL) process is used to form the first routing layer 105 and the second routing layer 106. The first routing layer 105 is connected to the functional device 103. The first routing layer 105 and the second routing layer 106 are connected, for example, via metallized through-holes 109a extending through the thickness of the package substrate 104, thereby enabling signal transmission between the functional device 103 and the two routing layers and the sealing film layer in the thickness direction.

[0062] It should be noted that the timing of removing the carrier 101 can be selected based on actual needs. For example, the carrier 101 may be removed before setting the first routing layer 105 and the second routing layer. Alternatively, one of the first routing layer 105 and the second routing layer 106 may be set first, then the carrier 101 may be removed, and then the other of the first routing layer 105 and the second routing layer 106 may be set.

[0063] In this embodiment of the present application, the injection mold cavity is provided with a raised structure at the position corresponding to the acoustic hole 107. A thin film covers the raised structure, allowing the acoustic hole 107 to be formed in one step during the injection molding process, eliminating the need for subsequent drilling of the package substrate 104. This manufacturing method effectively reduces the number of processing steps, and the acoustic hole 107 has high dimensional accuracy and a fixed shape. This manufacturing method is suitable for large-scale, batch production of microelectromechanical sensors.

[0064] In one example, as mentioned above, the two wiring layers located in the thickness direction of the package substrate 104 are connected through a metallized through-hole 109 a.

[0065] A plurality of metallized through holes 109a are provided around the functional device 103. The metallized through holes 109a are spaced apart from the functional device 103. The plurality of metallized through holes 109a make the connection between the two wiring layers more stable.

[0066] For example, the metallized through hole 109a can be formed by insert-molding a conductor component; or it can be formed by first opening the through hole 109 and then performing electroplating or chemical plating on the through hole 109.

[0067] In one example, the step of providing the carrier 101, the functional device 103 and the injection mold, wherein the surface of the cavity of the injection mold is provided with a film, includes: providing a conductor element;

[0068] The step of mounting the functional device 103 on the first surface of the carrier 101 includes: mounting the conductor element on the first surface of the carrier 101;

[0069] The step of attaching the injection mold to the first surface, forming a package substrate 104 by injection molding, embedding the functional device 103 in the package substrate 104, and forming the acoustic hole 107 along the thickness direction of the package substrate 104 during the injection molding process includes: embedding the conductor element in the package substrate 104;

[0070] The steps of removing the carrier 101 and forming routing layers on two surfaces of the package substrate 104 in the thickness direction, wherein the two routing layers in the thickness direction of the package substrate 104 are connected, and the routing layers are connected to the functional device 103, include: removing the carrier 101 to expose the conductor element;

[0071] The two wiring layers located in the thickness direction of the packaging substrate 104 are connected through the conductor element.

[0072] In this example, if Figures 9 and 10 As shown, before injection molding, a conductive element and functional device 103 are mounted together on the first surface of a carrier sheet 101. For example, they are mounted on an adhesive film 102 bonded to the first surface. The conductive element can be made of metal, graphite, conductive glass, etc. In this example, the conductive element is a copper pillar 108. Of course, the conductive element can also be made of aluminum, gold, silver, nickel, stainless steel, etc. Figure 9 、 Figure 10 The sound hole 107 is omitted.

[0073] During the injection molding process, the copper pillars 108 are embedded into the package substrate 104 .

[0074] After the carrier wafer 101 is removed, the functional devices 103 and the copper pillars 108 are exposed on the surface of the package substrate 104 bonded to the first surface of the carrier wafer 101 .

[0075] The copper pillars 108 can function as electrical connections. After the routing layers are set, the first routing layer 105 and the second routing layer 106 are connected together through the copper pillars 108 .

[0076] In this example, copper pillars 108 can be embedded in the package substrate 104 in batches during the injection molding process, thereby saving the subsequent step of providing metallized through-holes 109 a. This method is suitable for large-scale, batch production of micro-electromechanical sensors.

[0077] In one example, after the step of embedding the conductor element in the packaging substrate 104, the method includes:

[0078] The surface of the package substrate 104 facing away from the carrier 101 is ground to expose one end of the conductive material.

[0079] In general, the thickness of the package substrate 104 formed by injection molding is greater than the required thickness of the package substrate 104, so the copper pillar 108 is buried in the package substrate 104. Figure 11 As shown, a lapping process is performed to thin the side of the package substrate 104 facing away from the carrier 101, thereby exposing one end of the copper pillar 108 on this side. During this process, the thickness of the package substrate 104 reaches the required thickness. Thus, through the lapping process, the two ends of the copper pillar 108 are exposed on two surfaces of the package substrate 104 in the thickness direction.

[0080] In one example, the carrier 101 is removed and routing layers are formed on two surfaces in the thickness direction of the packaging substrate 104, the two routing layers located in the thickness direction of the packaging substrate 104 are connected, and in the step of connecting the routing layers with the functional device 103, the two routing layers located in the thickness direction of the packaging substrate 104 are respectively connected to the two ends of the conductor element.

[0081] In this example, if Figure 8 As shown, after two routing layers are formed, the two routing layers, namely the first routing layer 105 and the second routing layer 106 , are connected to two ends of the copper pillar 108 respectively.

[0082] In one example, the step of attaching the injection mold to the first surface, forming the package substrate 104 by injection molding, embedding the functional device 103 in the package substrate 104, and forming the acoustic hole 107 along the thickness direction of the package substrate 104 during the injection molding process includes:

[0083] A through hole 109 is provided along the thickness direction of the packaging substrate 104;

[0084] A conductor element is formed in the through hole 109 ; wherein the two wiring layers located in the thickness direction of the packaging substrate 104 are connected through the conductor element.

[0085] like Figures 12 to 13 As shown, a carrier chip 101 and a functional device 103 are provided. The functional device 103 is mounted on the first surface of the carrier chip 101. The above steps are as described above and will not be described in detail here. Figures 12 to 14 The sound hole 107 is omitted.

[0086] like Figure 14As shown, a through hole 109 is opened on the package substrate 104 by laser etching, plasma etching or mechanical drilling. For example, the through hole 109 is set around the functional device 103.

[0087] Next, a conductor element is placed in through-hole 109. The conductor element can be made of metal, graphite, conductive glass, or the like. For example, the conductor element is a copper pillar 108. Copper pillar 108 is filled into through-hole 109. Alternatively, metal can be formed in through-hole 109 by electroplating or chemical plating to form metallized through-hole 109a.

[0088] In one example, forming the conductor element in the through hole 109 includes: sputtering a seed layer 110 on an inner wall of the through hole 109;

[0089] Conductor elements are formed in the through holes 109 by electroplating or chemical plating.

[0090] like Figures 15 and 16 As shown, a seed layer 110 is sputtered on the side of the package substrate 104 facing away from the carrier 101. The seed layer 110 covers the surface of the package substrate 104 on this side and the inner wall of the through hole 109. During electroplating, a plated layer is formed on the inner wall of the through hole 109.

[0091] In one example, before the step of forming the conductor element in the through hole 109 by electroplating or chemical plating, the method further includes:

[0092] The seed layer 110 on the surface of the packaging substrate 104 facing away from the carrier 101 is removed.

[0093] In order to avoid the formation of a coating in an unnecessary position, it is necessary to first remove the seed layer 110 covering the side surface of the packaging substrate 104. For example, the seed layer 110 on the surface of the packaging substrate 104 is removed by chemical mechanical polishing (CMP). During the CMP process, the polishing liquid is continuously dripped onto the polishing pad. The chemical components in the polishing liquid first react slightly with the material to be removed from the surface of the packaging layer, softening it. Then, the polishing head applies pressure and moves relative to the polishing pad to physically remove the reactants to achieve the purpose of removing the seed layer 110 and leveling the side surface.

[0094] Alternatively, the seed layer 110 on the side surface can be removed using a photoresist-protected etching method. For example, photoresist is first applied to the through-hole 109; then, the desired pattern is transferred to the photoresist using a photolithography process. During the etching process, the photoresist protects the through-hole 109, while areas not covered by the photoresist, such as the seed layer 110 on the side surface of the package substrate 104, are eroded by the etchant.

[0095] Of course, the method of removing the seed layer 110 is not limited to the above embodiment, and those skilled in the art can configure it according to actual needs.

[0096] like Figure 17 As shown, after removing the seed layer 110 on the side surface of the package substrate 104, a conductor element, such as a copper pillar 108, is formed on the inner wall of the through hole 109 by electroplating or chemical plating, and finally a metallized through hole 109a is formed.

[0097] In one example, after the step of forming a conductor element in the through hole 109 by electroplating or chemical plating, the method further includes:

[0098] A planarization process is performed on the side of the conductor element facing away from the package substrate 104 .

[0099] like Figure 18 As shown, during electroplating or chemical plating, to ensure that the copper pillars 108 fill the through-holes 109, the formed copper pillars 108 generally protrude from the surface of the package substrate 104 on the side facing away from the carrier 101. To facilitate processing of the trace layer, this side of the package substrate 104 needs to be flattened. For example, this side can be polished by grinding so that the conductor elements are flush with the surface of the package substrate 104 on this side.

[0100] In one example, the step of attaching the injection mold to the first surface, forming the package substrate 104 by injection molding, embedding the functional device 103 in the package substrate 104, and forming the acoustic hole 107 along the thickness direction of the package substrate 104 during the injection molding process further includes:

[0101] forming a wiring layer on one surface of the packaging substrate 104 in a thickness direction;

[0102] A through hole 109 is formed along the thickness direction of the packaging substrate 104;

[0103] A metal layer is provided on the inner wall of the through hole 109;

[0104] A wiring layer is formed on the other surface of the packaging substrate 104 in the thickness direction, and two ends of the metal layer are respectively connected to the two wiring layers.

[0105] like Figures 6 to 8 As shown, in this example, first, a first wiring layer 105 is formed by electroplating, for example, the first wiring layer 105 is formed on the bottom surface of the package substrate 104;

[0106] Next, a through hole 109 is formed from the top surface of the package substrate 104 , with one end of the through hole 109 extending to the first wiring layer 105 . For example, the through hole 109 is formed by laser etching, plasma etching, or mechanical drilling.

[0107] Furthermore, the through hole 109 is metallized by electroplating to form a metallized through hole 109 a . In this process, one end of the metallized through hole 109 a is connected to the first wiring layer 105 .

[0108] Next, a second wiring layer 106 is formed on the top surface of the package substrate 104. The second wiring layer 106 is connected to the other end of the metallized through hole 109a.

[0109] In this example, since the functional device 103 exposes the bottom surface of the packaging substrate 104, and it is necessary to first form a first routing layer 105 on the bottom surface of the packaging substrate 104 and connect the first routing layer 105 to the functional device 103, the carrier 101 is removed before preparing the first routing layer 105.

[0110] In other examples, it is necessary to first form the second trace layer 106 on the top surface of the package substrate 104. After forming the second trace layer 106, the carrier 101 can be removed, and then the first trace layer 105 can be formed. Alternatively, the carrier 101 can be removed first, and then the second trace layer 106 and the first trace layer 105 can be formed in sequence.

[0111] According to another embodiment of the present application, a micro-electromechanical sensor is provided. The micro-electromechanical sensor is prepared according to the preparation method described in the present application. For example, the micro-electromechanical sensor structure generally includes a packaging shell, a packaging cover, a chip, leads, etc. The packaging shell or packaging cover is prepared using the above-mentioned preparation method. The chip is, for example, a microphone chip, a temperature sensing chip, a humidity sensing chip, a gas sensing chip, a memory chip, a communication chip, an ASIC chip, a microprocessor chip, etc. Some chips are arranged in the packaging shell, and some chips are embedded in the packaging shell or packaging cover.

[0112] According to another embodiment of the present application, an electronic device is provided. The electronic device includes the microelectromechanical packaging structure of the present application. The electronic device is, for example, a mobile phone, a laptop computer, a tablet computer, a television, a smartwatch, a VR device, an AR device, an XR device, etc.

[0113] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0114] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A method for preparing a micro-electromechanical sensor, characterized in that: include: A carrier sheet (101), a functional device (103) and an injection mold are provided, wherein a film is attached to the surface of the cavity of the injection mold; Mounting the functional device (103) on the first surface of the carrier (101); The injection mold is attached to the first surface, and a packaging substrate (104) is formed by injection molding, wherein the functional device (103) is embedded in the packaging substrate (104), and a sound hole (107) is formed along the thickness direction of the packaging substrate (104) during the injection molding process; removing the injection mold and the film; The carrier (101) is removed and wiring layers are formed on two surfaces in the thickness direction of the packaging substrate (104), the two wiring layers in the thickness direction of the packaging substrate (104) are connected, and the wiring layers are connected to the functional device (103).

2. The preparation method according to claim 1, characterized in that The two wiring layers located in the thickness direction of the packaging substrate (104) are connected via a metallized through hole (109a).

3. The preparation method according to claim 1, characterized in that The step of providing a carrier (101), a functional device (103) and an injection mold, wherein a thin film is attached to the surface of the cavity of the injection mold, comprises: providing a conductor element; The step of mounting the functional device (103) on the first surface of the carrier (101) comprises: mounting the conductor element on the first surface of the carrier (101); The step of attaching the injection mold to the first surface, forming a package substrate (104) by injection molding, burying the functional device (103) in the package substrate (104), and forming a sound hole (107) along the thickness direction of the package substrate (104) during the injection molding process comprises: burying the conductor element in the package substrate (104); The steps of removing the carrier (101) and forming wiring layers on two surfaces in the thickness direction of the packaging substrate (104), wherein the two wiring layers in the thickness direction of the packaging substrate (104) are connected, and the wiring layers are connected to the functional device (103), include: removing the carrier (101) to expose the conductor element; The two wiring layers located in the thickness direction of the packaging substrate (104) are connected via the conductor element.

4. The preparation method according to claim 3, characterized in that After the step of embedding the conductor element in the packaging substrate (104), the method further comprises: The surface of the packaging substrate (104) facing away from the carrier (101) is ground to expose one end of the conductive material.

5. The preparation method according to claim 3, characterized in that The carrier (101) is removed and routing layers are formed on two surfaces in the thickness direction of the packaging substrate (104), the two routing layers located in the thickness direction of the packaging substrate (104) are connected, and in the step of connecting the routing layers to the functional device (103), the two routing layers located in the thickness direction of the packaging substrate (104) are respectively connected to the two ends of the conductor element.

6. The preparation method according to claim 1, characterized in that The step of attaching the injection mold to the first surface, forming a package substrate (104) by injection molding, burying the functional device (103) in the package substrate (104), and forming a sound hole (107) along the thickness direction of the package substrate (104) during the injection molding process, further includes: A through hole is provided along the thickness direction of the packaging substrate (104); A conductor element is formed in the through hole; wherein the two wiring layers located in the thickness direction of the packaging substrate (104) are connected through the conductor element.

7. The preparation method according to claim 6, characterized in that The forming of the conductor element in the through hole comprises: sputtering a seed layer (110) on the inner wall of the through hole; Conductor elements are formed in the through holes by electroplating or chemical plating.

8. The preparation method according to claim 7, characterized in that Before the step of forming a conductor element in the through hole by electroplating or chemical plating, the method further comprises: The seed layer (110) on the surface of the packaging substrate (104) facing away from the carrier (101) is removed.

9. The preparation method according to claim 7, characterized in that After the step of forming a conductor element in the through hole by electroplating or chemical plating, the method further includes: A flattening process is performed on the side of the conductor element facing away from the packaging substrate (104).

10. The preparation method according to claim 7, characterized in that The through holes are formed by laser etching, plasma etching or mechanical drilling.

11. The preparation method according to claim 1, characterized in that The steps of forming a wiring layer on the two surfaces of the removed carrier (101) and the packaging substrate (104) in the thickness direction, connecting the two wiring layers in the thickness direction of the packaging substrate (104), and connecting the wiring layer to the functional device (103) include: forming a wiring layer on one surface of the packaging substrate (104) in a thickness direction; forming a through hole along the thickness direction of the packaging substrate (104); providing a metal layer on the inner wall of the through hole; A wiring layer is formed on the other surface of the packaging substrate (104) in the thickness direction, and two ends of the metal layer are respectively connected to the two wiring layers.

12. A micro-electromechanical sensor, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 11.

13. An electronic device, characterized in that: Comprising the micro-electromechanical sensor according to claim 12.

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