Microphone

Abstract

The utility model provides a microphone. The microphone comprises a shell, a circuit board, a first chip assembly and a second chip assembly, wherein the circuit board is fixed on the shell in a covering manner and forms a cavity together with the shell; the first chip assembly is fixed on one side, close to the shell, of the circuit board; the circuit board is formed by stacking a plurality of layers of structures and comprises a chip mounting layer, a first wiring layer, a plurality of shielding layers, a second wiring layer and an SMT layer which are sequentially arranged at intervals from the side close to the first chip assembly to the side away from the first chip assembly, and the shielding layers comprise the multiple layers which are sequentially arranged. The plurality of shielding layers are respectively connected to a grounding point of the circuit board, and each shielding layer is provided with an avoiding hole penetrating through the shielding layer. The microphone provided by the utility model can reduce the interference of the heat emitted by the ASIC chip in the working process on the performance of other chips.

Description

Technical Field

[0001] The utility model relates to the technical field of sound-to-electricity conversion, in particular to a new microphone. Background Art

[0002] A microphone is an energy-circulating device that converts sound into electronic signals. It mainly includes a housing, a circuit board that is surrounded by the housing to form a cavity, a MEMS chip fixed on the circuit board, and an ASIC chip fixed in the circuit board.

[0003] When the MEMS chip and ASIC chip in the related technology work together, the ASIC chip will generate a lot of heat, which will be dissipated through the substrate of the circuit board or through the thermal movement of the air in the cavity. Both of these heat dissipation methods will affect the performance of other chips, especially chips that are easily affected by heat, thereby causing the performance of these chips to decrease.

[0004] Therefore, it is necessary to provide a new microphone to solve the above problems. Utility Model Content

[0005] The utility model aims to provide a new microphone to solve the problem that the microphone of the related art easily affects the performance of other chips by heat conduction of the substrate of the circuit board or heat movement of the air to dissipate heat.

[0006] In order to solve the above problems, the utility model provides a microphone, which includes a shell, a circuit board that is fixed to the shell and forms a cavity with the shell, a first chip component that is fixed to the circuit board near the side of the shell and located in the cavity and electrically connected to the circuit board, and a second chip component that is buried and fixed in the circuit board and electrically connected to the circuit board, the shell or the circuit board is provided with a sound inlet hole running through it, and the second chip component is electrically connected to the first chip component; the circuit board is formed by stacking a multi-layer structure, which includes a chip mounting layer, a first routing layer, a shielding layer, a second routing layer and an SMT layer that are sequentially arranged from a side close to the first chip component to a side away from the first chip component, the chip mounting layer, the first routing layer, the second routing layer and the SMT layer are electrically connected to each other, the second chip component is electrically connected to the first routing layer, the shielding layer includes multiple layers that are arranged in sequence, the multiple layers of the shielding layers are respectively connected to the grounding point of the circuit board, each of the shielding layers is provided with an avoidance hole running through it, the avoidance holes on all the shielding layers together constitute an avoidance space, and the second chip component is accommodated in the avoidance space.

[0007] Preferably, the chip mounting layer, the first routing layer, the shielding layer, the second routing layer and the SMT layer are metal layers respectively.

[0008] Preferably, the circuit board includes a first conductive column, and the first conductive column is electrically connected to the second chip component, the first routing layer and the chip mounting layer in sequence.

[0009] Preferably, the circuit board further comprises a second conductive column, which is electrically connected to the chip mounting layer, the first wiring layer, the second wiring layer and the SMT layer in sequence; and the avoidance hole is also used to avoid the second conductive column.

[0010] Preferably, the first chip assembly includes a first MEMS chip and a second MEMS chip fixed to the circuit board at intervals.

[0011] Preferably, the second chip assembly includes a first ASIC chip and a second ASIC chip that are spaced apart; the first ASIC chip is electrically connected to the first MEMS chip, and the second ASIC chip is electrically connected to the second MEMS chip.

[0012] Preferably, the first ASIC chip is electrically connected to the first MEMS chip via a first connecting line, and the second ASIC chip is electrically connected to the second MEMS chip via a second connecting line.

[0013] Preferably, in the multilayer structure of the circuit board, any one of FR4, ceramic, polyimide and polyimide film materials is filled between two adjacent layers.

[0014] Compared with the prior art, the microphone of the present invention designs a multi-layer structure formed by stacking circuit boards into a chip mounting layer, a first routing layer, a shielding layer, a second routing layer and an SMT layer that are arranged in sequence, and defines that the shielding layer includes multiple layers arranged in sequence, and the multiple shielding layers are respectively connected to the grounding points of the circuit board, and each shielding layer is provided with an avoidance hole running through it, and the avoidance holes on all the shielding layers together constitute an avoidance space, and the second chip component is accommodated in the avoidance space, so that the heat generated by the ASIC chip in the circuit board during operation can be guided out to the outside through the shielding layer and the grounding point in sequence, thereby reducing the interference of the heat generated by the ASIC chip during operation on the performance of other chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0016] Figure 1An overall cross-sectional schematic diagram of a microphone provided by an embodiment of the utility model;

[0017] Figure 2 A schematic cross-sectional view of a circuit board portion of a microphone provided by an embodiment of the utility model;

[0018] Figure 3 A design layout diagram of a shielding layer in a microphone provided in an embodiment of the utility model.

[0019] 100, microphone; 1, housing; 2, circuit board; 21, chip mounting layer; 22, first routing layer; 231, first shielding layer; 232, second shielding layer; 233, avoidance hole; 2331, first ASIC chip avoidance position; 2332, second ASIC chip avoidance position; 2333, first avoidance position of conductive column; 2334, second avoidance position of conductive column; 24, second routing layer; 25, SMT layer; 26, grounding point; 261, grounding layer conductive column; 27, first conductive column; 28, second conductive column; 3, first chip assembly; 31, first MEMS chip; 32, second MEMS chip; 4, second chip assembly; 41, first ASIC chip; 42, second ASIC chip; 5, first connecting line; 6, second connecting line; 10, cavity; 20, sound inlet hole. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] The present invention provides a microphone 100, Figure 1 to Figure 2 As shown, it includes a shell 1, a circuit board 2 which is covered and fixed on the shell 1 and together with the shell 1 forms a cavity 10, a first chip component 3 which is fixed to the side of the circuit board 2 close to the shell 1 and is located in the cavity 10 and is electrically connected to the circuit board 2, and a second chip component 4 which is buried and fixed in the circuit board 2 and is electrically connected to the circuit board 2, and the second chip component 4 is electrically connected to the first chip component 3.

[0022] The housing 1 or the circuit board 2 is provided with a sound inlet hole 20 penetrating therethrough. The sound inlet hole 20 in this embodiment is located at a position of the circuit board 2 corresponding to the first MEMS chip 31 below.

[0023] The first chip assembly 3 includes a first MEMS chip 31 and a second MEMS chip 32 fixed to the circuit board 2 at intervals; the second chip assembly 4 includes a first ASIC chip 41 and a second ASIC chip 42 arranged at intervals; the first ASIC chip 41 is electrically connected to the first MEMS chip 31, and the second ASIC chip 42 is electrically connected to the second MEMS chip 32.

[0024] In this embodiment, the first ASIC chip 41 is electrically connected to the first MEMS chip 31 through a first connection line 5 , and the second ASIC chip 42 is electrically connected to the second MEMS chip 32 through a second connection line 6 .

[0025] The circuit board 2 is formed by stacking a multi-layer structure, which includes a chip mounting layer 21, a first routing layer 22, a shielding layer, a second routing layer 24 and an SMT layer 25 (SMT surface) arranged in sequence from a side close to the first chip component 3 to a side away from the first chip component 3. The chip mounting layer 21, the first routing layer 22, the second routing layer 24 and the SMT layer 25 are electrically connected to each other, the second chip component 4 is electrically connected to the first routing layer 22, the shielding layer includes multiple layers arranged in sequence, and the multiple shielding layers are respectively connected to the grounding point 26 of the circuit board 2, each shielding layer is provided with an avoidance hole 233 running through it, and the avoidance holes 233 on all the shielding layers together constitute an avoidance space, and the second chip component 4 is accommodated in the avoidance space.

[0026] The hierarchical structure of the circuit board 2 includes at least six layers, that is, the shielding layer includes at least two layers, and the avoidance hole 233 of the shielding layer is not only used to accommodate and avoid the second chip assembly 4, but also used to avoid the following second conductive column 28 or other structures that need to be conductive on the circuit board 2. Figure 3 As shown, the shielding layer includes multiple avoidance holes 233, which respectively form a first ASIC chip avoidance position (avoidance space) 2331, a second ASIC chip avoidance position (avoidance space) 2331, a first avoidance position 2333 of the conductive column, a second avoidance position 2334 of the conductive column, and a sound inlet hole avoidance position, etc.

[0027] In the multi-layer structure of the circuit board 2, any one of FR4, ceramic, polyimide (PI) and polyimide film (FPC) materials is filled between two adjacent layers.

[0028] In this embodiment, the shielding layer includes two layers, namely a first shielding layer 231 and a second shielding layer 232 .

[0029] The grounding point (grounding layer) 26 is provided with a grounding layer conductive column 261 to achieve a conductive function.

[0030] The first wiring layer 22 , the shielding layer, the second wiring layer 24 and the SMT (surface mount) layer are metal layers, such as a copper layer, an aluminum layer, a nickel layer, a gold layer, a metal alloy layer, etc.

[0031] The circuit board 2 includes a first conductive column 27 , and the first conductive column 27 is electrically connected to the second chip assembly 4 , the first wiring layer 22 and the chip mounting layer 21 in sequence.

[0032] The circuit board 2 further includes a second conductive column 28 , which is electrically connected to the chip mounting layer 21 , the first wiring layer 22 , the second wiring layer 24 and the SMT layer 25 in sequence.

[0033] In this embodiment, the two ends of the first connecting line 5 are respectively connected to the pads (Pad) on the first conductive column 27 connected to the first ASIC chip 41 and the pads on the first MEMS chip 31; the two ends of the second connecting line 6 are respectively connected to the pads (Pad) on the first conductive column 27 connected to the second ASIC chip 42 and the pads on the second MEMS chip 32.

[0034] The pads on the circuit board 2 are located on the same side or two opposite sides of the circuit board 2 or in the middle area of ​​the circuit board 2 .

[0035] According to actual needs, sensor chips such as pressure sensors, microphone sensors, and gas sensors can also be applied to the microphone 100 in this embodiment.

[0036] The microphone 100 in this embodiment designs a multi-layer structure formed by stacking the circuit board 2 into a chip mounting layer 21, a first routing layer 22, a shielding layer, a second routing layer 24 and an SMT layer 25 arranged in sequence, and defines that the shielding layer includes multiple layers arranged in sequence, and the multiple shielding layers are respectively connected to the grounding point 26 of the circuit board 2, each shielding layer is provided with an avoidance hole 233 running through it, and the avoidance holes 233 on all the shielding layers together constitute an avoidance space, and the second chip component 4 is accommodated in the avoidance space, so that the heat generated by the ASIC chip in the circuit board 2 during operation can be guided out of the outside through the shielding layer and the grounding point 26 in sequence, thereby reducing the interference of the heat generated by the ASIC chip during operation on the performance of other chips.

[0037] The above is only an implementation method of the present invention. It should be pointed out that a person skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements are all within the protection scope of the present invention.

Claims

1. A microphone, comprising a housing, a circuit board fixed to the housing and forming a cavity with the housing, a first chip assembly fixed to the circuit board near the housing and located in the cavity and electrically connected to the circuit board, and a second chip assembly embedded and fixed in the circuit board and electrically connected to the circuit board, the housing or the circuit board is provided with a sound inlet hole penetrating therethrough, and the second chip assembly is electrically connected to the first chip assembly; characterized in that The circuit board is formed by stacking a multi-layer structure, which includes a chip mounting layer, a first routing layer, a shielding layer, a second routing layer and an SMT layer, which are arranged in sequence from a side close to the first chip component to a side away from the first chip component. The chip mounting layer, the first routing layer, the second routing layer and the SMT layer are electrically connected to each other, the second chip component is electrically connected to the first routing layer, the shielding layer includes multiple layers arranged in sequence, and the multiple shielding layers are respectively connected to the grounding points of the circuit board, each of the shielding layers is provided with an avoidance hole running through it, and the avoidance holes on all the shielding layers together constitute an avoidance space, and the second chip component is accommodated in the avoidance space.

2. The microphone according to claim 1, wherein The chip mounting layer, the first routing layer, the shielding layer, the second routing layer and the SMT layer are metal layers respectively.

3. The microphone according to claim 1, wherein: The circuit board includes a first conductive column, and the first conductive column is electrically connected to the second chip component, the first routing layer and the chip mounting layer in sequence.

4. The microphone according to claim 3, characterized in that The circuit board also includes a second conductive column, which is electrically connected to the chip mounting layer, the first routing layer, the second routing layer and the SMT layer in sequence; the avoidance hole is also used to avoid the second conductive column.

5. The microphone according to claim 1, wherein: The first chip assembly includes a first MEMS chip and a second MEMS chip fixed to the circuit board at an interval.

6. The microphone according to claim 5, characterized in that The second chip assembly includes a first ASIC chip and a second ASIC chip which are spaced apart from each other; the first ASIC chip is electrically connected to the first MEMS chip, and the second ASIC chip is electrically connected to the second MEMS chip.

7. The microphone according to claim 6, characterized in that The first ASIC chip is electrically connected to the first MEMS chip via a first connection line, and the second ASIC chip is electrically connected to the second MEMS chip via a second connection line.

8. The microphone according to claim 1, wherein: In the multi-layer structure of the circuit board, any one of FR4, ceramic, polyimide and polyimide film materials is filled between two adjacent layers.

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