Packaging structure of microphone assembly and microphone
By setting the bias voltage module and the processing module separately in two ASIC chips, the problem of interference of the bias voltage module in the MEMS microphone is solved, the signal-to-noise ratio and stability are improved, the design difficulty and cost are reduced, and the different performances are adapted to need.
Patent Information
- Application Number
- CN202323423337.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-15
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2033-12-15
AI Technical Summary
In existing MEMS microphones, the bias voltage module generates a large interference signal to other modules, which affects the signal-to-noise ratio and stability, and is more difficult and cost-effective.
By setting the bias voltage module and the processing module in two ASIC chips respectively, the interference between the modules is reduced. The first ASIC chip is responsible for providing a stable bias voltage, and the second ASIC chip is responsible for signal processing to avoid interference, and according to performance ASIC chips with different performances are required.
It improves the signal-to-noise ratio and stability of the microphone, reduces the design difficulty and development difficulty, and at the same time improves the degree of modularity to adapt to different performance needs.
Smart Images
Figure CN222169966U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of micro-electromechanical systems, and in particular to a packaging structure of a microphone component and a microphone. Background Art
[0002] MEMS microphones are mainly composed of MEMS chips, ASIC chips, PCB substrates and shells. The ASIC chip serves as an acoustic-electrical signal conversion processor, which is generally composed of Bias, In, Vdd, Data / Out, Clock, L / R and Gnd polarity.
[0003] In existing MEMS microphones, these polarities are integrated into the same ASIC chip, and the mutual interference between the modules is relatively large. In particular, the bias voltage module is particularly sensitive to the interference signals generated by other modules, and the interference between the modules needs to be minimized. Utility Model Content
[0004] The embodiment of the utility model provides a packaging structure of a microphone assembly and a microphone, wherein a module having greater interference with a bias voltage module and the bias voltage module are respectively arranged in two ASIC chips through two ASIC chips, thereby reducing interference to the bias voltage module.
[0005] In order to solve the above technical problems, the embodiments of the present utility model disclose the following technical solutions:
[0006] In one aspect, a packaging structure of a microphone assembly is provided, comprising:
[0007] substrate;
[0008] A shell is arranged on one side of the substrate, and the shell and the substrate are arranged to form a cavity;
[0009] A MEMS chip, a first ASIC chip, and a second ASIC chip, wherein the MEMS chip, the first ASIC chip, and the second ASIC chip are arranged on the substrate and accommodated in the cavity;
[0010] The first ASIC chip includes a bias voltage terminal connected to a bias voltage module, the second ASIC chip includes a signal input terminal connected to a processing module, the MEMS chip includes a first detection electrode and a second detection electrode, the first detection electrode and the second detection electrode are configured to form a detection capacitor, the first detection electrode is electrically connected to the bias voltage terminal, and the second detection electrode is electrically connected to the signal input terminal;
[0011] The substrate is provided with a through hole penetrating along the thickness thereof, or the shell is provided with a through hole penetrating along the thickness thereof.
[0012] In addition to or as an alternative to one or more of the features disclosed above, the second ASIC chip further includes a signal output terminal, and the signal output terminal is electrically connected to the circuit in the substrate through a wire.
[0013] In addition to or as an alternative to one or more of the features disclosed above, the first ASIC chip further includes a power supply terminal and a ground terminal, and the power supply terminal and the ground terminal are electrically connected to the second ASIC chip; the first ASIC chip is stacked on the second ASIC chip, and the power supply terminal and the ground terminal of the first ASIC chip are electrically connected to the second ASIC chip through wires.
[0014] In addition to or as an alternative to one or more of the features disclosed above, the first ASIC chip is bonded to the second ASIC chip by glue.
[0015] In addition to or as an alternative to one or more of the features disclosed above, the first ASIC chip further includes a power terminal and a ground terminal; the first ASIC chip is fixedly mounted on the substrate, the power terminal and the ground terminal of the first ASIC chip are electrically connected to the substrate through wires, and the power terminal and the ground terminal are electrically connected to the second ASIC chip through a circuit in the substrate.
[0016] In addition to or as an alternative to one or more of the features disclosed above, the second ASIC chip further includes a first filter capacitor, the first filter capacitor includes a first filter electrode and a second filter electrode, the first filter electrode is electrically connected to the bias voltage terminal, and the second filter electrode is electrically connected to a ground terminal in the second ASIC chip.
[0017] In addition to or as an alternative to one or more of the features disclosed above, the MEMS chip further comprises a first pad, a second pad and a third pad;
[0018] The first pad is electrically connected to the first detection electrode, the second pad is electrically connected to the second detection electrode, and the third pad is electrically connected to the first pad; the first pad is connected to the bias voltage terminal through a wire, the second pad is connected to the signal input terminal on the second ASIC chip through a wire, and the first filter electrode is connected to the third pad through a wire.
[0019] In addition to or as an alternative to one or more features disclosed above, an annular welding ring is provided on the substrate, the MEMS chip, the first ASIC chip and the second ASIC chip are all arranged in the welding ring, and the housing is connected to the welding ring by welding.
[0020] In addition to or as an alternative to one or more of the features disclosed above, when the substrate is provided with a through hole penetrating along the thickness of the substrate, the MEMS chip covers the through hole.
[0021] On the other hand, a microphone is further disclosed. In addition to or as an alternative to one or more of the features disclosed above, the microphone includes a packaging structure of the microphone assembly as described in any one of the above items.
[0022] One of the above technical solutions has the following advantages or beneficial effects: the present application separates the bias voltage module from the processing module for processing the signal, wherein the bias voltage module is arranged in the first ASIC chip and the processing module is arranged in the second ASIC chip, thereby avoiding interference of the processing module with the bias voltage module, so that the bias voltage value provided by the first ASIC chip to the MEMS chip is stable, thereby improving the signal-to-noise ratio and stability of the microphone. Compared with the difficulty of designing a device with the same performance as the present application in terms of signal-to-noise ratio and stability in the same ASIC chip, the present application greatly reduces the design difficulty of arranging the bias voltage module and the processing module in two ASIC chips respectively, and can design the corresponding first ASIC chip and the second ASIC chip according to different performance requirements (such as analog signal microphone, digital signal microphone, high AOP performance or adjustable bias voltage circuit, etc.), and combine the first ASIC chip and the second ASIC chip with different performance to meet the performance requirements, thereby improving the modularization degree of the present application and greatly reducing the development difficulty of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The technical solutions and other beneficial effects of the present invention will be made apparent by describing in detail the specific embodiments of the present invention in conjunction with the accompanying drawings.
[0024] Figure 1 It is a structural schematic diagram of the packaging structure of a microphone assembly in the prior art;
[0025] Figure 2 is a schematic diagram of a top view of the packaging structure of a microphone assembly provided according to the first embodiment of the utility model;
[0026] Figure 3 is a schematic diagram of a top view of the packaging structure of a microphone assembly provided in accordance with the second embodiment of the present utility model;
[0027] Figure 4 is a schematic side view of the packaging structure of the microphone assembly provided in the second embodiment of the present utility model;
[0028] Figure 5is a schematic diagram of a top view of the packaging structure of a microphone assembly provided according to the third embodiment of the present utility model;
[0029] In the figure: 1'-substrate; 3'-MEMS chip; 5'-ASIC chip; 61'-first wire; 62'-second wire; 63'-third wire; 1-substrate; 101-welding ring; 102-through hole; 2-housing; 3-MEMS chip; 301-first pad; 302-second pad; 303-third pad; 4-first ASIC chip; 5-second ASIC chip; 61-first wire; 62-second wire; 63-third wire; 64-fourth wire; 65-fifth wire. DETAILED DESCRIPTION
[0030] In order to make the purpose, technical solution and beneficial effects of the utility model clearer, the utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific implementation methods described in this specification are only for explaining the utility model, and are not intended to limit the utility model.
[0031] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present utility model, the meaning of "multiple" refers to two or more, unless otherwise clearly and specifically defined.
[0032] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0033] In the present utility model, unless otherwise clearly stipulated and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.
[0034] See also Figure 1 , Figure 1 The schematic diagram of the structure of the packaging structure of the microphone assembly in the prior art is shown. The packaging structure of the microphone assembly in the prior art includes: a substrate 1' and a shell, the substrate and the shell are surrounded by a cavity, and the MEMS chip 3' and the ASIC chip 5' arranged on the substrate 1' are both accommodated in the cavity. The ASIC chip 5' is electrically connected to the ASIC chip 5' through a plurality of first conductive wires 61' to realize the functions of powering the ASIC chip 5' and outputting signals of the ASIC chip 5', and the MEMS chip 3' and the ASIC chip 5' are electrically connected through the second wire 62' and the third wire 63' to realize powering the MEMS chip 3' and inputting signals to the ASIC chip 5'. In the prior art, the number of ASIC chips 5' in the packaging structure of the microphone assembly is one, and the ASIC chip 5' includes a bias voltage (Bias) module for powering the MEMS chip 3' and other polarity modules, wherein the bias voltage module is easily interfered by other polarity modules, thereby affecting the output signal of the MEMS chip 3' and the microphone signal-to-noise ratio and other performances. If the output signal of the MEMS chip 3' and the microphone signal-to-noise ratio are required not to change with the voltage output by the bias voltage module to the MEMS chip, very high performance requirements will be imposed on the ASIC chip 5', greatly increasing the design difficulty and production cost.
[0035] See also Figure 2 As shown, Figure 2The schematic diagram of the top view of the packaging structure of the microphone assembly provided according to the first embodiment of the utility model is shown. In this embodiment, the packaging structure of the microphone assembly includes: a substrate 1 and a shell 2, the substrate 1 and the shell 2 are surrounded to form a cavity, a MEMS chip 3, a first ASIC chip 4 and a second ASIC chip 5 are arranged on the substrate 1, an annular welding ring 101 is arranged on the substrate 1, the shell 2 is welded and connected to the welding ring 101, the MEMS chip 3, the first ASCI chip 4 and the second ASIC chip 5 are all arranged within the range of the welding ring 101, and the MEMS chip 3, the first ASIC chip 4 and the second ASIC chip 5 are all accommodated in the cavity. A through hole 102 is provided on the substrate 1 that runs through the thickness thereof, the MEMS chip 3 covers the through hole 102, and the back cavity in the MEMS chip 3 is connected to the through hole 102. Among them, a bias voltage module is provided in the first ASIC chip 4, and the first ASIC chip 4 includes a bias voltage terminal (Bias), a power supply terminal (Vdd) and a ground terminal (Gnd) connected to the bias voltage module. The bias voltage terminal is electrically connected to the MEMS chip 3 through the second wire 62, and the power supply terminal and the ground terminal are electrically connected to the substrate 1 through the fourth wire 64. The first ASIC chip 4 provides a bias voltage to the MEMS chip 3. Specifically, the MEMS chip 3 includes a detection capacitor for responding to sound pressure activities, the detection capacitor includes a first detection electrode and a second detection electrode, and the bias voltage terminal is electrically connected to the first detection electrode. The second ASIC chip 5 includes a signal input terminal and a signal output terminal, the signal input terminal is electrically connected to the MEMS chip 3 through the third wire 63, and the signal output terminal is electrically connected to the substrate 1 through the first wire 61. Specifically, the signal input terminal is electrically connected to the second detection electrode of the detection capacitor.
[0036] The present application separates the bias voltage module from the processing module for processing the signal, wherein the bias voltage module is arranged in the first ASIC chip 4 and the processing module is arranged in the second ASIC chip 5, thereby avoiding interference of the processing module with the bias voltage module, so that the bias voltage value provided by the first ASIC chip 4 to the MEMS chip 3 is stable, thereby improving the signal-to-noise ratio and stability of the microphone. Compared with the difficulty of designing a device with the same performance as the present application in terms of signal-to-noise ratio and stability in the same ASIC chip, the present application greatly reduces the design difficulty of arranging the bias voltage module and the processing module in two ASIC chips respectively, and can design the corresponding first ASIC chip 4 and second ASIC chip 5 according to different performance requirements (such as analog signal microphone, digital signal microphone, high AOP performance or adjustable bias voltage circuit, etc.), and combine the first ASIC chip 4 and the second ASIC chip 5 with different performance to meet the performance requirements, thereby improving the modularization degree of the present application and greatly reducing the development difficulty of the present application.
[0037] In this embodiment, a through hole 102 is provided on the substrate 1 and runs through the substrate 1 along its thickness, and the MEMS chip 3 covers the through hole 102 to form a rear sound microphone technical solution. In other embodiments, a through hole 102 is provided on the housing 2, and the MEMS chip 3 is arranged on the inner wall of the housing 2 and covers the through hole 102 to form a front sound microphone technical solution, which is not specifically limited here.
[0038] Reference Figure 3 and Figure 4 As shown, Figure 3 and Figure 4 The top view and side view of the packaging structure of the microphone assembly provided in the second embodiment of the present invention are respectively shown. Compared with the first embodiment, in the second embodiment, the first ASIC chip 4 is stacked on the second ASIC chip 5, and the first ASIC chip 4 is glued to the second ASIC chip 5. The power supply terminal and the ground terminal of the first ASIC chip 4 are electrically connected to the power supply terminal and the ground terminal of the second ASIC chip 5 through the fourth wire 64.
[0039] In this embodiment, the first ASIC chip 4 and the second ASIC chip are stacked, which improves the space utilization of the packaging structure in the height direction and reduces the overall area of the packaging structure, which is beneficial to the miniaturization of the present application.
[0040] Reference Figure 5 As shown, Figure 5 A schematic diagram of a top view of the packaging structure of a microphone assembly provided according to Embodiment 3 of the present utility model is shown. Compared with Embodiment 2, in Embodiment 3, a first filter capacitor is provided in the second ASIC chip 5, and the first filter capacitor is electrically connected to the bias voltage module in the first ASIC chip 4 to eliminate clutter interference, reduce low-frequency noise, and thus improve the product performance of the present application. The bias voltage module in the first ASIC chip 4 includes a second filter capacitor, and the first filter capacitor and the second filter capacitor are used in a superimposed manner. However, due to the size of the first ASIC chip 4 and the circuit layout, it is difficult to design a larger capacitance of the second filter capacitor. The capacitance of the first filter capacitor is greater than the capacitance of the second filter capacitor.
[0041] Specifically, the first filter capacitor includes a first filter electrode and a second filter electrode. A first pad 301, a second pad 302 and a third pad 303 are provided on the MEMS chip 3, wherein the first pad 301 is electrically connected to the first detection electrode in the detection capacitor, the second pad 302 is electrically connected to the second detection electrode in the detection capacitor, and the third pad 303 is connected to the first pad 301. The first pad 301 is connected to the bias voltage terminal through the second wire 62, the second pad 302 is connected to the signal input terminal on the second ASIC chip 5 through the third wire 63, the first filter electrode is connected to the third pad 303 through the fifth wire 65, so that the first filter electrode is electrically connected to the bias voltage terminal of the first ASIC chip, and the second filter electrode is electrically connected to the ground terminal in the second ASIC chip 5, so that the first filter capacitor forms a Bias-GND filter.
[0042] Due to the small size of the first ASIC chip 4, it is difficult to set a larger first filter capacitor. The larger the capacitance of the first filter capacitor, the better the filtering effect. The first filter capacitor with a larger capacitance is set in the large-sized second ASIC chip 5 and is used in combination with the second filter capacitor in the bias voltage module in the first ASIC chip 4, so as to achieve a better filtering effect, enhance the anti-interference ability of the present application, improve the signal quality, and thus enhance the product performance of the microphone.
[0043] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0044] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.
Claims
1. A packaging structure of a microphone assembly, It is characterized in that include: substrate; A shell is arranged on one side of the substrate, and the shell and the substrate are arranged to form a cavity; A MEMS chip, a first ASIC chip, and a second ASIC chip, wherein the MEMS chip, the first ASIC chip, and the second ASIC chip are arranged on the substrate and accommodated in the cavity; The first ASIC chip includes a bias voltage terminal connected to a bias voltage module, the second ASIC chip includes a signal input terminal connected to a processing module, the MEMS chip includes a first detection electrode and a second detection electrode, the first detection electrode and the second detection electrode are configured to form a detection capacitor, the first detection electrode is electrically connected to the bias voltage terminal, and the second detection electrode is electrically connected to the signal input terminal; The substrate is provided with a through hole penetrating along the thickness thereof, or the shell is provided with a through hole penetrating along the thickness thereof.
2. The packaging structure of the microphone assembly according to claim 1, It is characterized in that The first ASIC chip further includes a power supply terminal and a ground terminal, and the power supply terminal and the ground terminal are electrically connected to the second ASIC chip; the first ASIC chip is stacked on the second ASIC chip, and the power supply terminal and the ground terminal of the first ASIC chip are electrically connected to the second ASIC chip through wires.
3. The packaging structure of the microphone assembly as claimed in claim 2, It is characterized in that The first ASIC chip is bonded to the second ASIC chip by glue.
4. The packaging structure of the microphone assembly according to claim 1, It is characterized in that The first ASIC chip also includes a power supply terminal and a ground terminal; the first ASIC chip is fixedly mounted on the substrate, the power supply terminal and the ground terminal of the first ASIC chip are electrically connected to the substrate through wires, and the power supply terminal and the ground terminal are electrically connected to the second ASIC chip through a circuit in the substrate.
5. The packaging structure of the microphone assembly according to claim 1, It is characterized in that The second ASIC chip further includes a first filter capacitor, which includes a first filter electrode and a second filter electrode, the first filter electrode is electrically connected to the bias voltage terminal, and the second filter electrode is electrically connected to a ground terminal in the second ASIC chip.
6. The packaging structure of the microphone assembly as claimed in claim 5, It is characterized in that The MEMS chip also includes a first pad, a second pad and a third pad; The first pad is electrically connected to the first detection electrode, the second pad is electrically connected to the second detection electrode, and the third pad is electrically connected to the first pad; the first pad is connected to the bias voltage terminal through a wire, the second pad is connected to the signal input terminal on the second ASIC chip through a wire, and the first filter electrode is connected to the third pad through a wire.
7. The packaging structure of the microphone assembly according to claim 1, It is characterized in that An annular welding ring is arranged on the substrate, the MEMS chip, the first ASIC chip and the second ASIC chip are all arranged in the welding ring, and the housing is connected to the welding ring by welding.
8. The packaging structure of the microphone assembly as claimed in claim 1, It is characterized in that In the case where a through hole is provided on the substrate and penetrates the substrate along the thickness thereof, the MEMS chip covers the through hole.
9. The packaging structure of the microphone assembly according to claim 1, It is characterized in that The second ASIC chip also includes a signal output terminal, and the signal output terminal is electrically connected to the circuit in the substrate through a wire.
10. A microphone, It is characterized in that A packaging structure comprising the microphone assembly as claimed in any one of claims 1 to 9.