Microphone, sound pickup device, and electronic device
By integrating an ASIC chip into the substrate and utilizing an internal blind hole design, the problem of miniaturization of MEMS microphones was solved, resulting in a more compact structure and higher signal-to-noise ratio performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WEIFANG GOERTEK MICROELECTRONICS CO LTD
- Filing Date
- 2025-06-06
- Publication Date
- 2026-06-02
AI Technical Summary
Existing MEMS microphones cannot meet the requirements for miniaturization.
By integrating the ASIC chip into the substrate and setting a first blind via in the substrate to allow the metal leads to pass through, the space occupied by the cavity is reduced, and a more compact vertical stacking structure is achieved.
The overall package thickness and volume of MEMS microphones have been reduced, improving signal-to-noise ratio performance and meeting the requirements for miniaturization and high performance.
Smart Images
Figure CN224319514U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of sound acquisition technology, and in particular to a microphone, a sound pickup device, and an electronic device. Background Technology
[0002] MEMS microphones (Micro-Electro-Mechanical Systems microphones) are miniature microphones based on semiconductor manufacturing processes. They achieve sound-to-electricity conversion by integrating acoustic sensing structures and signal processing circuits onto a silicon chip. Compared to traditional electret microphones (ECMs), MEMS microphones are characterized by their small size, strong anti-interference capabilities, high temperature stability, and good consistency.
[0003] MEMS microphones typically consist of a MEMS chip and an ASIC chip, both of which are mounted on a substrate. However, as customer requirements increase, the size requirements for MEMS microphones are also getting smaller and smaller, and existing MEMS microphone structures can no longer meet the demand for miniaturization. Utility Model Content
[0004] The main purpose of this invention is to provide a microphone, sound pickup device, and electronic device, which aims to solve the problem that existing MEMS microphone structures can no longer meet the requirements for miniaturization.
[0005] To achieve the above objectives, the present invention provides a MEMS microphone comprising:
[0006] shell;
[0007] A substrate, wherein the opposite sides of the substrate are a first side and a second side, the outer shell is disposed on the first side of the substrate and forms a receiving cavity with the substrate, an ASIC chip is integrated in the substrate, and a first blind hole is formed on the substrate, the first blind hole extending from the first side to the ASIC chip;
[0008] The MEMS chip is located within the receiving cavity. The substrate has a pickup hole that communicates with the back cavity of the MEMS chip. The pickup hole is spaced apart from the ASIC chip. The MEMS chip is mounted on the first side of the substrate and covers the pickup hole. The MEMS chip and the ASIC chip are connected by a metal lead passing through the first blind hole.
[0009] In one embodiment, the substrate includes a PCB board, a first protective layer, and a second protective layer. The first protective layer and the second protective layer are disposed on opposite sides of the PCB board and form a first side and a second side, respectively. The MEMS chip is mounted on the first protective layer, and the ASIC chip is integrated into the PCB board and disposed close to the second protective layer. The first blind via extends from the first protective layer into the PCB board to the ASIC chip.
[0010] In one embodiment, the first blind hole passes sequentially through the first protective layer and the PCB board along the direction from the first side to the second side, then bends and changes direction, and extends through the second protective layer toward the ASIC chip.
[0011] In one embodiment, the first blind via includes an extension section and a connecting section. The extension section extends from the first protective layer toward the cavity side of the PCB board along the direction from the first side to the second side and extends to the second protective layer. The connecting section passes through the second protective layer and is connected to the end of the extension section away from the cavity, and extends along the extension direction of the second protective layer to the ASIC chip.
[0012] In one embodiment, the two ends of the ASIC chip are a first end and a second end, wherein the first end is disposed toward the pickup hole, the second end is disposed away from the pickup hole, and a first blind hole extends from the first side away from the first end to a position on the ASIC chip near the second end.
[0013] In one embodiment, the substrate has a second blind via extending from the second side to a position of the ASIC chip near the first end, and the ASIC chip is electrically connected to an external device through the second blind via.
[0014] In one embodiment, a second blind via is provided on the second side of the substrate, which communicates with the ASIC chip. The second blind via is disposed near the first end, and the ASIC chip is electrically connected to an external device through the second blind via.
[0015] In one embodiment, the second blind hole extends from the second side along a first direction to a position on the ASIC chip near the first end, where the first direction is the direction from the second side to the first side.
[0016] This utility model also provides a sound pickup device, which uses the above-mentioned MEMS microphone.
[0017] This utility model also proposes an electronic device, which applies the above-mentioned sound pickup device.
[0018] This invention integrates the ASIC chip within the substrate, eliminating the space occupied on the first side of the substrate. This allows the first side of the substrate to accommodate only the MEMS chip, reducing the overall package thickness of the MEMS microphone and enabling a more compact vertical stacking structure. This, in turn, reduces the size of the MEMS microphone, meeting miniaturization requirements. Furthermore, by placing the first blind via within the substrate, the metal leads connecting the MEMS chip and the ASIC chip can pass through the substrate, reducing the space occupied by the metal leads within the cavity and further reducing the overall size of the MEMS microphone. Simultaneously, the cavity contains only the MEMS chip, resulting in a larger cavity volume and higher signal-to-noise ratio performance, meeting high-performance requirements. This invention, through the substrate integration of the ASIC chip and the internal first blind via design, reduces the overall package thickness and size of the MEMS microphone, meeting miniaturization requirements. The fact that only the MEMS chip needs to be placed within the cavity allows for a larger MEMS chip design with a larger back cavity volume, resulting in higher signal-to-noise ratio performance and meeting the high-performance requirements of the MEMS microphone. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0020] Figure 1 This is a cross-sectional structural diagram of a MEMS microphone provided in an embodiment of the present invention.
[0021] Explanation of icon numbers:
[0022] 100. MEMS microphone; 1. Housing; 2. Substrate; 201. PCB board; 202. First protective layer; 203. Second protective layer; 21. First side; 22. Second side; 23. Receiving cavity; 24. Pickup hole; 25. First blind hole; 251. Extension section; 252. Connecting section; 26. Second blind hole; 3. ASIC chip; 31. First end; 32. Second end; 4. MEMS chip; 5. Metal lead wire.
[0023] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.
[0025] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.
[0026] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0027] MEMS microphones typically consist of a MEMS chip and an ASIC chip, both of which are mounted on a substrate. However, as customer requirements increase, the size requirements for MEMS microphones are also getting smaller and smaller, and existing MEMS microphone structures can no longer meet the demand for miniaturization.
[0028] To address the aforementioned problems, this utility model proposes a MEMS microphone 100.
[0029] Please see Figure 1The MEMS microphone 100 of this embodiment includes a housing 1, a substrate 2, and a MEMS chip 4. The two opposite sides of the substrate 2 are a first side 21 and a second side 22, respectively. The housing 1 covers the first side 21 of the substrate 2 and forms a receiving cavity 23 with the substrate 2. An ASIC chip 3 is integrated in the substrate 2, and the substrate 2 has a first blind hole 25 extending from the first side 21 to the ASIC chip 3. The MEMS chip 4 is located in the receiving cavity 23. The substrate 2 has a pickup hole 24 communicating with the back cavity of the MEMS chip. The pickup hole 24 is spaced apart from the ASIC chip 3. The MEMS chip 4 is mounted on the first side 21 of the substrate 2 and covers the pickup hole 24. The MEMS chip 4 and the ASIC chip 3 are connected by a metal lead 5 passing through the first blind hole 25.
[0030] The technical solution of this utility model integrates the ASIC chip 3 into the substrate 2, which does not occupy the space of the first side 21 of the substrate 2. This allows the first side 21 of the substrate 2 to only house the MEMS chip 4, thereby reducing the overall package thickness of the MEMS microphone 100 and achieving a more compact vertical stacking structure. This reduces the size of the MEMS microphone 100, meeting the miniaturization requirements. Simultaneously, by placing the first blind hole 25 within the substrate 2, the metal leads 5 connecting the MEMS chip 4 and the ASIC chip 3 can pass through the interior of the substrate 2, reducing the space occupied by the metal leads 5 within the receiving cavity 23 and further reducing the overall size of the MEMS microphone 100. Furthermore, since only the MEMS chip 4 is housed within the receiving cavity 23, the receiving cavity volume of the MEMS microphone 100 is larger, resulting in higher signal-to-noise ratio performance and meeting high-performance requirements. This invention reduces the overall package thickness of the MEMS microphone 100 by integrating the ASIC chip 3 into the substrate 2 and incorporating a first blind path, thereby reducing the size of the MEMS microphone 100 and meeting the miniaturization requirements of the MEMS microphone 100. At the same time, only the MEMS chip 4 needs to be placed in the cavity 23, allowing the MEMS chip 4 to be designed to be larger, with a larger back cavity volume and higher signal-to-noise ratio performance, thus meeting the high-performance requirements of the MEMS microphone 100.
[0031] In one embodiment, the substrate 2 includes a PCB board 201, a first protective layer 202 and a second protective layer 203. The first protective layer 202 and the second protective layer 203 are respectively disposed on opposite sides of the PCB board 201, forming a first side 21 and a second side 22. The MEMS chip 4 is mounted on the first protective layer 202. The ASIC chip 3 is integrated into the PCB board 201 and disposed close to the second protective layer 203. The first blind hole 25 extends from the first protective layer 202 into the PCB board 201 to the ASIC chip 3.
[0032] The first protective layer 202 and the second protective layer 203 are respectively disposed on opposite sides of the PCB board 201, and the ASIC chip 3 is integrated into the PCB board 201. The PCB board 201 can be wrapped by the first protective layer 202 and the second protective layer 203 to prevent water mist and dust from entering, extend the service life of the PCB board 201, avoid impact damage to the ASIC chip 3, and improve the safety of the ASIC chip 3. At the same time, the ASIC chip 3 is set close to the second protective layer 203, so that the heat of the ASIC can be quickly conducted to the external heat dissipation structure through the second protective layer 203, reducing the heat transferred inward to the receiving cavity 23, and preventing the heat accumulation in the receiving cavity 23 from affecting the performance of the MEMS chip 4.
[0033] In one embodiment, the first blind hole 25 passes through the first protective layer 202 and the PCB board 201 sequentially from the first side to the second side, then bends and changes direction, and extends through the second protective layer 203 toward the ASIC chip 3.
[0034] The bending design of the first blind hole 25 allows it to avoid critical structures within the PCB board 201 without affecting the performance of the PCB board 201 itself. At the same time, the first blind hole 25 extends only in two directions, passing through the first protective layer 202 and the PCB board 201 before bending and changing direction to extend directly towards the ASIC chip 3, which can minimize the interference of the first blind hole 25 on the internal structure of the PCB board 201.
[0035] In one embodiment, the first blind via 25 includes an extension 251 and a connecting section 252. The extension 251 extends from the first protective layer 202 toward the receiving cavity 23 through the PCB board 201 and to the second protective layer 203 in a direction from the first side to the second side. The connecting section 252 passes through the second protective layer 203 and is connected to the end of the extension 251 away from the receiving cavity 23, and extends along the extension direction of the second protective layer 203 to the ASIC chip 3. Understandably, the metal lead 5 is shortest when it is obliquely inserted into the substrate 2, but oblique insertion will affect other components in the PCB board 201. Therefore, the extension 251 passes perpendicularly through the PCB board 201 and the first protective layer 202, which can minimize the length of the extension 251. The connecting section 252 extends in the same direction as the second protective layer 203, so that the total length of the extension 251 and the connecting section 252 is the shortest without affecting other components, reducing signal attenuation and reducing the volume of the metal lead 5 and the first blind via 25.
[0036] In one embodiment, the first protective layer 202 is a copper foil laid on the PCB board 201, completely covering the side of the PCB board 201 facing the first protective layer 202; the second protective layer 203 is a copper foil laid on the PCB board 201, completely covering the side of the PCB board 201 facing the second protective layer 203. The copper foil provides physical protection and buffering for the PCB board 201, and also shields against external electromagnetic interference, thereby improving the overall signal-to-noise ratio of the MEMS microphone 100. Furthermore, the copper foil has strong thermal conductivity, making it easier to transfer the heat generated by the MEMS chip 4 and the ASIC chip 3 to the external environment, ensuring the efficient operation of the MEMS microphone 100.
[0037] In one embodiment, the two ends of the ASIC chip 3 are a first end 31 and a second end 32, respectively. The first end 31 is disposed towards the pickup hole 24, and the second end 32 is disposed away from the pickup hole 24. A first blind hole 25 extends from a position away from the first end to a position of the ASIC chip 3 near the second end. The first end 31 is close to the pickup hole 24 and the MEMS chip 4, where there is significant electrical noise and electromagnetic interference. Therefore, the first blind hole 25 is disposed at a position of the ASIC chip 3 away from the first end 31, that is, on the outside of the second end 32 of the ASIC chip 3. This allows the metal lead 5 within the first blind hole 25 to avoid electrical noise and electromagnetic interference, thereby improving the stability of signal transmission and enhancing the overall acoustic performance of the MEMS microphone 100.
[0038] In one embodiment, a second blind hole 26 is provided on the second side 22 of the substrate 2, which is connected to the ASIC chip 3. The second blind hole 26 extends from the second side to a position of the ASIC chip 3 near the first end 31. The ASIC chip 3 is electrically connected to an external device through the second blind hole 26.
[0039] The output terminal of ASIC chip 3 is directly connected to external devices through the second blind hole 26 and is located at the first end 31 to avoid interference with the metal lead 5, while avoiding long-distance internal PCB traces and reducing electromagnetic interference, signal attenuation and noise coupling.
[0040] In one embodiment, the second blind hole 26 extends from the second side 22 along a first direction to a position near the first end 31 of the ASIC chip 3, where the first direction is from the second side 22 to the first side 21. The second blind hole 26 extends directly outward from the ASIC chip 3 in a direction perpendicular to the substrate 2. The gold fingers of the external device insert into the second blind hole 26 and connect directly to the ASIC chip 3, eliminating the need for wire transmission. This allows the output signal to be directly transmitted to the external device, avoiding signal attenuation and noise interference during transmission and improving the acoustic performance of the MEMS microphone 100.
[0041] This utility model also provides a sound pickup device, which uses the aforementioned MEMS microphone 100. The specific structure of the MEMS microphone 100 is as described in the above embodiments. Since this sound pickup device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.
[0042] This utility model also proposes an electronic device that applies the aforementioned sound pickup device. The specific structure of the sound pickup device is as described in the above embodiments. Since this electronic device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.
[0043] The above are merely optional embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made under the concept of this utility model using the contents of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.
Claims
1. A MEMS microphone, characterized in that, include: shell; A substrate, wherein the opposite sides of the substrate are a first side and a second side, the outer shell is disposed on the first side of the substrate and forms a receiving cavity with the substrate, an ASIC chip is integrated in the substrate, and a first blind hole is formed on the substrate, the first blind hole extending from the first side to the ASIC chip; The MEMS chip is located within the receiving cavity. The substrate has a pickup hole that communicates with the back cavity of the MEMS chip. The pickup hole is spaced apart from the ASIC chip. The MEMS chip is mounted on the first side of the substrate and covers the pickup hole. The MEMS chip and the ASIC chip are connected by a metal lead passing through the first blind hole.
2. The MEMS microphone as described in claim 1, characterized in that, The substrate includes a PCB board, a first protective layer and a second protective layer. The first protective layer and the second protective layer are disposed on opposite sides of the PCB board and form the first side and the second side, respectively. The MEMS chip is mounted on the first protective layer, and the ASIC chip is integrated into the PCB board and disposed close to the second protective layer. The first blind via extends from the first protective layer into the PCB board to the ASIC chip.
3. The MEMS microphone as described in claim 2, characterized in that, The first blind hole passes through the first protective layer and the PCB board sequentially from the first side to the second side, then bends and changes direction, and extends through the second protective layer toward the ASIC chip.
4. The MEMS microphone as described in claim 3, characterized in that, The first blind via includes an extension section and a connecting section. The extension section extends from the first protective layer toward the cavity side of the PCB board along the direction from the first side to the second side and extends to the second protective layer. The connecting section passes through the second protective layer and is connected to the end of the extension section away from the cavity, and extends to the ASIC chip along the extension direction of the second protective layer.
5. The MEMS microphone as described in claim 2, characterized in that, The first protective layer is a copper foil laid on the PCB board and covering the entire side of the PCB board facing the first protective layer; The second protective layer is a copper foil laid on the PCB board and covering the entire side of the PCB board facing the second protective layer.
6. The MEMS microphone as described in any one of claims 1 to 5, characterized in that, The ASIC chip has a first end and a second end at its two ends, wherein the first end is disposed toward the pickup hole, and the second end is disposed away from the pickup hole. A first blind hole extends from the first side away from the first end to a position on the ASIC chip near the second end.
7. The MEMS microphone as described in claim 6, characterized in that, The substrate has a second blind hole extending from the second side to a position of the ASIC chip near the first end, and the ASIC chip is electrically connected to an external device through the second blind hole.
8. The MEMS microphone as described in claim 7, characterized in that, The second blind hole extends from the second side along a first direction to a position on the ASIC chip near the first end, where the first direction is the direction from the second side to the first side.
9. A sound pickup device, characterized in that, The sound pickup device employs a MEMS microphone as described in any one of claims 1 to 8.
10. An electronic device, characterized in that, The electronic device employs the sound pickup device as described in claim 9.