A back-input microphone with double pads
By adopting a dual pad structure in the microphone, the outer pad surrounds the inner pad, the problem of insufficient airtightness of the traditional microphone is solved and a larger and clearer sound output is achieved.
Patent Information
- Application Number
- CN201911397905.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2019-12-30
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2039-12-30
AI Technical Summary
The single pad structure on the PCB board of a traditional microphone causes a gap between the external circuit and the pad, resulting in poor airtightness, causing sound to slip away from the pores or notches, which is small and unclear.
A dual pad structure is adopted, where the outer pad surrounds the inner pad, increases the connection area, ensures the airtightness of the electrical components, and improves the microphone pad through the combination of the inner pad, the outer pad and the strip pad. Airtightness.
It effectively avoids the problem of insufficient airtightness of single pads, improves the sound size and clarity of the microphone, and makes the background sound enter without loss, making the sound louder and clearer.
Smart Images
Figure CN111010637B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of microphones, and in particular to a back-input sound microphone with double pads. Background Art
[0002] The pad structure on the PCB of a traditional microphone is a ring. When the surface mounting process on the microphone PCB is performed, a gap may be created between the external circuit of the microphone and the pad, thereby creating a gap or hole, causing poor airtightness. Especially for microphones with back-input sound (the sound inlet is set on the PCB), poor airtightness will cause the sound to escape through the hole or gap, resulting in low sound, unclear sound, and other problems. Summary of the invention
[0003] The object of the present invention is to provide a back-input sound microphone with double pads to solve the above technical problems.
[0004] The technical problem solved by the present invention can be achieved by adopting the following technical solutions:
[0005] A back-input sound microphone with double pads, comprising
[0006] A circuit substrate, a packaging shell is buckled on the circuit substrate, a microphone assembly is installed on the top of the circuit substrate, a first pin, a second pin and a third pin are arranged on the circuit substrate, and the bottom surface of the circuit substrate is arranged:
[0007] an acoustic through hole;
[0008] At least one inner pad, in a closed ring shape, connected to the first pin;
[0009] At least one outer pad, in a closed ring shape, surrounding the outer side of the inner pad and connected to the first pin;
[0010] A plurality of rectangular pads, at least one of the rectangular pads is connected to the second pin, and at least one of the rectangular pads is connected to the third pin.
[0011] Preferably, the packaging shell is a metal shell, and the circuit substrate is a ceramic PCB.
[0012] Preferably, the distance between the inner pad, the outer pad and the acoustic sensor is not less than 2 mm, and the distance between the inner pad, the outer pad and the dedicated integrated chip is not less than 2 mm.
[0013] Preferably, the inner pad and the outer pad are both in annular shape, and the inner pad and the outer pad are concentric.
[0014] Preferably, the inner pad is connected to the outer pad via a strip pad.
[0015] Preferably, the inner pads, the outer pads and the strip pads are all electrically connected to the circuit substrate.
[0016] Preferably, the first pin and the inner pad and the outer pad are both output terminals, the second pin and the rectangular pad connected to the second pin are both power input terminals, and the third pin and the rectangular pad connected to the third pin are both ground terminals.
[0017] Preferably, the microphone assembly comprises an acoustic sensor, and the acoustic sensor is arranged corresponding to the position of the acoustic through hole.
[0018] Beneficial effect: The present invention adopts a method of surrounding the inner pad with an outer pad, which increases the connection area of the pad and avoids the problem of insufficient airtightness of a single pad. The double pads connect electrical components, improve the airtightness of the microphone pad, and make the background sound type microphone have no sound loss, and the microphone sound is louder and clearer. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a schematic cross-sectional view of the back-input sound microphone of the present invention;
[0020] Figure 2 It is a schematic diagram of the back structure of the circuit substrate of the present invention.
[0021] In the figure: 1-circuit substrate; 2-package shell; 3-acoustic through hole; 4-acoustic sensor; 5-external pad; 6-inner pad; 7-rectangular pad; 8-strip pad;
[0022] 11- first pin; 12- second pin; 13- third pin. DETAILED DESCRIPTION
[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.
[0025] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.
[0026] like Figure 1 and Figure 2As shown, the present invention provides a back-input sound microphone with double pads, comprising
[0027] A circuit substrate 1, a packaging shell 2 is buckled on the circuit substrate 1, a microphone assembly is installed on the top of the circuit substrate 1, and the bottom surface of the circuit substrate 1 is provided with: a first pin 11, a second pin 12 and a third pin 13 are provided on the circuit substrate 1,
[0028] One acoustic through hole 3;
[0029] A plurality of rectangular pads 7 ; at least one rectangular pad 7 is connected to the second pin 11 , and at least one rectangular pad 7 is connected to the third pin 13 .
[0030] At least one inner pad 6, in a closed ring shape, disposed on the bottom surface of the circuit substrate 1;
[0031] At least one outer pad 5 is in a closed ring shape and is disposed outside the inner pad 6. The inner pad 3 and the outer pad 5 are both connected to the first pin. The circuit of the microphone is connected to the circuit of the external device of the microphone through the inner pad or the outer pad. The circuit of the microphone transmits the signal to the external device of the microphone through the inner pad or the outer pad.
[0032] The advantages of the present invention are:
[0033] The present invention adopts a method of surrounding the inner pad with an outer pad, which increases the connection area of the pad and avoids the problem of insufficient airtightness of a single pad. The double pads connect electrical components, improves the airtightness of the microphone pad, and ensures that the background sound microphone has no sound loss, and the microphone sound is louder and clearer.
[0034] The first pin 11 and the inner pad and the outer pad are both output terminals, the second pin and the rectangular pad connected to the second pin are both power input terminals, and the third pin and the rectangular pad connected to the third pin are both ground terminals.
[0035] Or the first pin and the inner pad 6 and the outer pad 5 are both power input terminals, the second pin 12 and the rectangular pad 7 connected to the second pin are both output terminals, and the third pin 13 and the rectangular pad 7 connected to the third pin are both ground terminals.
[0036] Or the first pin 11 and the inner pad 6 and the outer pad 5 are all ground terminals, the second pin 12 and the rectangular pad 7 connected to the second pin are all output terminals, and the third pin 13 and the rectangular pad 7 connected to the third pin are all output terminals.
[0037] Preferably, the three pads ensure power input, grounding and signal output of the microphone, thereby ensuring normal operation of the microphone.
[0038] The microphone assembly includes an acoustic sensor 4 , and the acoustic sensor 4 is arranged corresponding to the position of the acoustic through hole 3 .
[0039] As a preferred embodiment of the present invention, the packaging shell 2 is a metal shell, which can well protect the electronic components in the microphone and protect the electronic components from damage by external forces and from electromagnetic or electrostatic interference.
[0040] The circuit substrate 1 is a ceramic PCB. The MEMS microphone has high precision but is very fragile, so the stress cannot be too large. The expansion coefficient of the ceramic in the ceramic PCB (Printed Circuit Board) is close to that of the silicon in the chip material, and no large stress will be generated during packaging or temperature changes. The copper layer of the ceramic printed circuit board does not contain an oxide layer, and has corrosion resistance and other characteristics in the face of various complex environments, thereby improving stability and reliability. In addition, the ceramic PCB also has good thermal conductivity and high temperature resistance, which increases the service life of the MEMS microphone and improves the microphone's ability to adapt to harsh environments.
[0041] As a preferred embodiment of the present invention, the acoustic sensor 4 is electrically connected to the circuit substrate 1. The internal circuit of the circuit substrate 1 provides the acoustic sensor 4 with necessary current and voltage support to ensure the normal operation of the acoustic sensor 4.
[0042] As a preferred embodiment of the present invention, the distance between the inner pad and the outer pad and the acoustic sensor is not less than 2 mm, and the distance between the inner pad and the outer pad and the dedicated integrated chip is not less than 2 mm. Because the inner pad and the outer pad will generate heat when the pad is welded to the external electronic device of the microphone, and the distance between the pad and the acoustic sensor and the dedicated integrated chip is greater than 2 mm, it can effectively avoid uneven heating and deformation of the chip area on the circuit board, resulting in uneven force on various parts of the MEMS device, and ensure the integrity of important electronic devices on the circuit board.
[0043] like Figure 2 As shown, as a preferred embodiment of the present invention, the inner pad 6 and the outer pad 5 are both in annular shape, and the inner pad 6 and the outer pad 5 are concentric. The double annular pad has a simple processing technology, and there is a gap between the two annular pads, which saves pad area.
[0044] As a preferred embodiment of the present invention, the inner pad 6 is connected to the outer pad 5 via the strip pad 8. The internal circuit of the circuit substrate 1 can be connected to the external circuit of the microphone regardless of whether it is connected to the inner pad or the outer pad.
[0045] As a preferred embodiment of the present invention, the inner pad 6 , the outer pad 5 and the strip pad 8 are all electrically connected to the circuit substrate 1 .
[0046] The advantages of setting inner pads, outer pads and strip pads connecting two pads are as follows:
[0047] (1) The soldering area of components is increased, thereby reducing the possibility of component cold soldering and ensuring the long-term stable operation of the microphone;
[0048] (2) Double-layer solder pads, with the outer solder pads sleeved on the outside of the inner solder pads, thereby increasing the soldering area, reducing the pores, and improving the airtightness level of the connection between the solder pads and the external circuit components of the microphone;
[0049] (3) The inner pads, outer pads and strip pads are all connected to the circuit of the circuit substrate, and the connection between the pads and the circuit is tighter, which reduces the possibility of the pads falling off and increases the strength of the pads; and if any one or two pads are damaged or the solder on the corresponding pads falls off, the circuit is still smooth when the other pad is intact, which increases the fault tolerance of the pads and makes the circuit connection of the pads more firm and reliable;
[0050] (4) The inner pad, the outer pad and the strip pad are connected in an integrated structure, the processing technology is simple, and there are hollow parts between the pads, which will not block the holes of the external electronic devices of the microphone.
[0051] There are four rectangular pads 7, which can be set on one side of the inner pad and the outer pad. The rectangular pad 7 is electrically connected to the internal circuit of the circuit substrate through the second pin and the third pin, and is welded together with the external circuit of the microphone, playing a role in assisting the fixing and connecting of the circuit. The combination of multiple welding points makes the connection between the circuit substrate 1 and the microphone more secure. When the circuit substrate is subjected to external force, the welding of the inner pad and the outer pad is less likely to fall off, ensuring the stability of the circuit connection.
[0052] It can be added that in order to avoid the problem of poor airtightness of the acoustic through hole 3, the acoustic through hole can be set in the middle hole of the inner pad 3. After welding, the airtightness between the microphone and the outside is guaranteed. The airtightness is guaranteed, and the sound inlet hole is set corresponding to the acoustic through hole 3 to ensure the pure input of sound.
[0053] The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.
Claims
1. A back-input microphone with double pads, characterized in that: include A circuit substrate, a packaging shell is buckled on the circuit substrate, a microphone assembly is installed on the top of the circuit substrate, a first pin, a second pin and a third pin are arranged on the circuit substrate, and the bottom surface of the circuit substrate is arranged: an acoustic through hole; At least one inner pad, in a closed ring shape, connected to the first pin; At least one outer pad, in a closed ring shape, surrounding the outer side of the inner pad and connected to the first pin; A plurality of rectangular pads, at least one of the rectangular pads is connected to the second pin, and at least one of the rectangular pads is connected to the third pin; The inner pad is connected to the outer pad via a strip pad; The inner pad, the outer pad and the strip pad are all electrically connected to the circuit substrate; The inner pad, the outer pad and the strip pad are in an integrally connected structure.
2. A back-input microphone with double pads according to claim 1, characterized in that: The packaging shell is a metal shell, and the circuit substrate is a ceramic PCB.
3. The back-input microphone with double pads according to claim 1, characterized in that: The distance between the inner pad and the outer pad and the acoustic sensor is not less than 2 mm, and the distance between the inner pad and the outer pad and the dedicated integrated chip is not less than 2 mm.
4. The back-input microphone with double pads according to claim 1, characterized in that: The inner pad and the outer pad are both in annular shape, and the inner pad and the outer pad have the same center.
5. The back-input microphone with double pads according to claim 1, characterized in that: The first pin, the inner pad and the outer pad are all output terminals, the second pin and the rectangular pad connected to the second pin are all power input terminals, and the third pin and the rectangular pad connected to the third pin are all ground terminals.
6. The back-input sound microphone with double pads according to claim 1, characterized in that: The microphone assembly includes an acoustic sensor, and the acoustic sensor is arranged corresponding to the position of the acoustic through hole.