CN112469196A

CN112469196A - Mainboard, noise reduction method and terminal

Info

Publication number: CN112469196A
Application number: CN201910844463.9A
Authority: CN
Inventors: 林雪
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2019-09-06
Filing date: 2019-09-06
Publication date: 2021-03-09
Also published as: WO2021042889A1

Abstract

The application provides a mainboard, a noise reduction method and a terminal, wherein the mainboard comprises: a support and a filter capacitor; wherein: the filter capacitor is mounted on the support; the surface of the filter capacitor is covered with a solidified liquid resistance-capacitance layer, and the liquid resistance-capacitance layer comprises a liquid resistance-capacitance material; the liquid resistance-capacitance layer is used for reducing noise generated by the filter capacitor at the sounding position of the support piece.

Description

Mainboard, noise reduction method and terminal

Technical Field

The application relates to the technical field of electronic device packaging, in particular to a mainboard, a noise reduction method and a terminal.

Background

At present, a plurality of filter capacitors are integrated on a Printed Circuit Board (PCB) power network in various terminals, and a part of the filter capacitors have a significant piezoelectric effect. When power voltage fluctuates, the capacitor expands and contracts mechanically along with the change of voltage, and drives the PCB mainboard to vibrate regularly, and the frequency of vibration falls into the range that the human ear can catch, resulting in audio noise. The problem becomes more prominent when the output power becomes larger gradually as the main board becomes thinner, and especially when 5G terminals appear, the requirement for the overall size of the machine becomes more severe.

Disclosure of Invention

The application provides a mainboard, a noise reduction method and a terminal, which weaken audio noise caused by a capacitance piezoelectric effect.

In a first aspect, an embodiment of the present application provides a motherboard, including a supporting component and a filter capacitor; wherein:

the filter capacitor is mounted on the support; the surface of the filter capacitor is covered with a solidified liquid resistance-capacitance layer, and the liquid resistance-capacitance layer comprises a liquid resistance-capacitance material; the liquid resistance-capacitance layer is used for reducing noise generated by the filter capacitor at the sounding position of the support piece.

In a second aspect, an embodiment of the present application provides a noise reduction method, including:

confirming the sounding position of the main board supporting piece; wherein the sound emission position comprises at least one filter capacitor;

covering a liquid resistance-capacitance layer on the surface of the filter capacitor at the sounding position; the liquid resistance-capacitance layer comprises a liquid resistance-capacitance material and is used for reducing noise generated by the filter capacitor at the sounding position;

and solidifying the liquid resistance-capacitance layer.

In a third aspect, an embodiment of the present application provides a terminal, which includes a display screen and the main board of the first aspect.

This application is through the vocal position department on mainboard support piece, adopts liquid resistance-capacitance layer to cover the processing to filter capacitor, has solved the technical problem of the audio frequency noise that capacitor piezoelectric effect causes on the mainboard effectively to reduce the audio frequency noise that capacitor piezoelectric effect causes on the mainboard.

With regard to the above embodiments and other aspects of the present application and implementations thereof, further description is provided in the accompanying drawings description, detailed description and claims.

Drawings

Fig. 1a is a schematic structural diagram of a motherboard provided in the present application;

fig. 1b is a schematic diagram illustrating an effect of performing noise reduction processing on a motherboard through a liquid rc layer according to the present application;

fig. 1c is a schematic structural diagram of a main board provided in the present application;

fig. 2 is a schematic flow chart of a noise reduction method according to the present application;

fig. 3 is a schematic structural diagram of a terminal provided in the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more apparent, embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

In an exemplary embodiment, the present application provides a main board, and fig. 1a is a schematic structural diagram of the main board provided in the present application. The mainboard can be integrated on any type of terminal, such as a smart phone.

At present, the main solutions adopted for audio noise caused by the filter capacitor mainly include the following two aspects: the first is to optimize the hardware circuit design. By optimizing the layout of the devices, such as the mutual positions between the filter capacitors; and the noise caused by the vibration of the filter capacitor is weakened by methods such as optimizing the circuit design and reducing the voltage fluctuation on a power supply network. However, the effect of circuit optimization is limited by the form of the product, the experience of the engineer, and the like. Secondly, a howling prevention capacitor is used. The basic principle of the capacitor is that an isolation layer is added on a bonding pad of the existing filter capacitor to isolate the capacitor from a PCB mainboard, and even if the capacitor vibrates, the vibration cannot be completely transmitted to the PCB mainboard due to the existence of the isolation layer. However, such devices are generally expensive, and the price is about 5 times of that of a common filter capacitor (such as a ceramic capacitor). And because an isolation layer is added, the whole height of the capacitor is increased, and the application of the capacitor is very limited in the intelligent terminal which has high layout density and strict requirement on the thickness of the whole machine at present, especially in the 5G mobile phone in the future.

The embodiment of the application adopts the liquid resistance-capacitance layer to reduce the noise of the filter capacitor which vibrates, can realize the damping characteristic of the liquid resistance-capacitance layer, absorbs the vibration of the capacitor and avoids transmitting the vibration to the PCB mainboard. The audio noise caused by the piezoelectric effect of the filter capacitor can be effectively weakened, and the method is very suitable for terminal products with strict size requirements.

Correspondingly, as shown in fig. 1a, the main board provided by the present application includes: a support 10 and a filter capacitor 20; wherein: the filter capacitor 20 is mounted on the support 10; the surface of the filter capacitor 20 is covered with a solidified liquid resistance-capacitance layer 30, and the liquid resistance-capacitance layer 30 comprises a liquid resistance-capacitance material; the liquid rc layer 30 serves to reduce noise generated from the filter capacitor 20 at the sound emitting position of the support 10.

Among them, the support 10 may be a part for loading various components on the main board. The liquid resistive-capacitive layer 30 may cover the filter capacitor. The liquid resistive-capacitive material may be a material in liquid form, which has good damping properties. Illustratively, the liquid resistance-capacitance material may be glue or the like. The application is not limited to a specific material type of the liquid resistance-capacitance material.

Because the output power of the whole machine on the PCB mainboard is gradually improved, the power voltage is easy to fluctuate. The fluctuation of voltage leads to the mechanical vibration of filter capacitor, and then drives the vibration of PCB mainboard, and the frequency of vibration just falls into the human ear and receives the scope to cause the audio noise. Therefore, at least one filter capacitor is typically included at the sound emitting position of the PCB main board support.

In the present application, the damping characteristics of the liquid rc material can be utilized to absorb the mechanical vibration caused by the filter capacitor. Specifically, as shown in fig. 1a, a liquid rc layer 30 may be covered on the surface of the filter capacitor 20, and the liquid rc layer 30 is cured, so as to reduce noise generated by the filter capacitor 20 at the sound emitting position of the support 10 through the cured rc layer 30.

On the basis of the above-described embodiment, a modified embodiment of the above-described embodiment is proposed, and it is to be noted herein that, in order to make the description brief, only the differences from the above-described embodiment are described in the modified embodiment.

In one example, as shown in fig. 1a, the liquid rc layer 30 is formed by coating the surface of the filter capacitor 20 with a liquid rc material.

Specifically, the liquid rc layer 30 may be formed by coating the surface of the filter capacitor 20 with a liquid rc material. Alternatively, the coating method may be dipping, spraying, spot coating, spin coating, or the like, and the application does not limit the specific type of the coating method.

In one example, as shown in fig. 1a, in the case where a plurality of filter capacitors 20 are included at the sound emission position, the number of liquid resistance-capacitance layers 30 on the surfaces of all the filter capacitors 20 at the sound emission position is at least 1.

In the present application, if there are multiple filter capacitors at the sounding site, the liquid rc layer 30 can be used to cover all the filter capacitors in the area. Alternatively, a liquid rc layer 30 may be used to cover the entire filter capacitor. Alternatively, it is also possible to cover all the filter capacitors with a plurality of liquid rc layers 30, for example, one liquid rc layer 30 covers 2 or 3 filter capacitors. Accordingly, if there are a plurality of sound emitting positions, the liquid rc layer 30 may be used to cover the filter capacitors at the plurality of sound emitting positions, respectively.

In one example, the curing of the liquid resistive-capacitive layer may include: and heating the liquid resistance-capacitance layer according to a preset heating condition.

The preset heating condition may be a condition for heating and curing the liquid resistance-capacitance material. The liquid resistance-capacitance material is heated according to a preset heating condition to form a liquid resistance-capacitance layer, and the damping characteristic of the liquid resistance-capacitance layer needs to meet the noise reduction requirement.

Optionally, the curing treatment of the liquid resistance-capacitance layer may be a heating method. Specifically, the liquid resistance-capacitance layer covered on the surface of the filter capacitor can be heated by a heating device according to a preset heating condition.

In one example, the preset heating condition may include: the heating temperature reaches the set temperature, and/or the heating time reaches the first set time.

The set temperature may be a temperature set according to a damping characteristic requirement for achieving the noise reduction purpose, such as 60 ℃. The first set time may be a time set according to a damping characteristic requirement for achieving the noise reduction purpose, such as 10 minutes or the like. The specific values of the set temperature and the first set time are not limited in the embodiments of the present application.

Optionally, when the liquid resistance-capacitance layer covered on the surface of the filter capacitor is heated by the heating device according to a preset heating condition, the heating temperature needs to reach a set temperature, and/or the heating time needs to reach a first set time. Alternatively, the heating device may be an oven or the like, and the specific type of the heating device is not limited in the embodiments of the present application.

In one example, the curing of the liquid resistive-capacitive layer may include: and carrying out illumination treatment on the liquid resistance-capacitance layer according to a preset illumination condition.

The preset illumination condition can be the condition of curing the liquid resistance-capacitance layer by illumination. The liquid resistance-capacitance material is irradiated according to preset illumination conditions to form a liquid resistance-capacitance layer, and the damping characteristic of the liquid resistance-capacitance layer needs to meet the noise reduction requirement.

Optionally, the curing treatment may be performed by light irradiation. Specifically, the liquid resistance-capacitance layer covered on the surface of the filter capacitor can be subjected to illumination treatment by the illumination device according to a preset illumination condition.

In one example, the preset lighting conditions may include: the illumination intensity reaches the set illumination intensity, and/or the illumination time reaches a second set time.

Wherein the set illumination intensity can be an illumination intensity set according to the damping characteristic requirement for noise reduction, such as 60mW/cm²And the like. The second set time may be a time set according to a damping characteristic requirement for achieving the noise reduction purpose, such as 10 minutes or the like. Book (I)The application examples are not limited to specific values of the set illumination intensity and the second set time.

Optionally, when the liquid resistance-capacitance layer covered on the surface of the filter capacitor is subjected to illumination treatment by the illumination device according to a preset illumination condition, the illumination intensity needs to reach a set illumination intensity, and/or the illumination time needs to reach a second set time. Optionally, the light source corresponding to the illumination device may be an ultraviolet light source.

In one example, the liquid RC material may include glue, and the hardness of the glue after curing is within a preset hardness interval threshold range.

The preset hardness interval threshold may be a threshold range set according to an absorption effect of the audio noise.

Considering that the damping properties of glue are related to the stiffness of glue, which is related to the absorption effect of audio noise, an excessively stiff glue may deteriorate the audio noise level. Too soft glue may not have a significant noise improvement effect. Therefore, in the present application, it is necessary to determine the hardness of the glue after curing to ensure good audio noise absorption. Optionally, the preset hardness interval threshold of the glue suitable for the end product is approximately shore hardness 15-30.

Fig. 1b is a schematic diagram illustrating an effect of performing noise reduction processing on a motherboard through a liquid rc layer according to the present application. In a specific example, as shown in fig. 1b, glue with a certain viscosity may be sprayed or dispensed on the filter capacitor area on the PCB main board by using a glue dispensing device such as a spraying device or a dispensing device, and then the glue covering the filter capacitor may be cured. The solidification function is to change the glue from liquid state to solid state, so that the glue has certain hardness and is integrated with the covered circuit area. After the glue is completely cured, the vibration of the filter capacitor can be absorbed by utilizing the inherent damping characteristic of the glue, and the energy transferred to the PCB mainboard by the vibration is weakened, so that the audio noise caused by the vibration of the filter capacitor is reduced.

Optionally, the filter capacitor may include a ceramic capacitor, and the ceramic capacitor has advantages of low cost and small size, and is often used as a filter capacitor on a PCB main board power supply network. After the ceramic capacitor is subjected to noise reduction treatment by using glue, the noise reduction effect is close to that of the current noise reduction capacitor.

It can be understood that the anti-howling capacitor has a more significant increase in height than the conventional ceramic capacitor. In the present application, however, glue has the advantage of a very thin coating thickness. Taking 10V 4.7uf 0402 packaged ceramic capacitor as an example, the height of the whistling prevention capacitor is 0.2 mm-0.25 mm higher than that of the common ceramic capacitor. And the spraying thickness of the glue that is used for making an uproar in this application can reach the um level, can guarantee good noise reduction effect, can hardly exert an influence to the whole thickness of product again to can effectively improve the molding size competitiveness of terminal product. Therefore, the PCB mainboard provided by the application is thin and is suitable for terminal equipment using the ceramic filter capacitor in a large range. Especially intelligent terminal products. Because the requirement of the overall dimension of the intelligent terminal product is smaller and thinner, the thickness of the PCB main board is also being thinned, the thickness of the Mobile phone PCB in the GSM (Global System for Mobile Communication) era is about 1.0mm, and the thickness of the PCB main board of the current 5G Mobile phone is close to 0.5 mm. After the PCB mainboard is thinned by a wide margin, mainboard audio noise caused by capacitance vibration is more obvious. On the other hand, as the thickness of the mobile phone is required to be thinner and thinner, the height of the anti-howling capacitor which is generally used at present cannot be made to be very small, which becomes an irreparable restriction factor on a 5G mobile phone. The layout height and the area of the PCB mainboard are not obviously affected, and the design requirement of the 5G mobile phone is very suitable for the future.

Fig. 1c is a schematic structural diagram of a main board provided in the present application. As shown in fig. 1c, the main board in the present application may further include, in addition to the above components:

one or more processors 21 and storage 22; the number of the processors 21 of the motherboard can be one or more, and one processor 21 is taken as an example in fig. 1 c; the storage device 22 is used to store one or more programs; the one or more programs are executed by the one or more processors 21.

The processor 21 and the storage device 22 in the motherboard may be connected by a bus or other means, and fig. 1c illustrates the connection by a bus.

The storage device 22, which is a computer-readable storage medium, may be configured to store software programs, computer-executable programs, and modules. The storage device 22 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created according to use of the device, and the like. Further, the storage 22 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some examples, the storage device 22 may further include memory located remotely from the processor 21, which may be connected to the motherboard via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

In addition to the above components, the main board of the present application may further include: a radio frequency device 23 for transmitting or receiving a radio frequency signal; a battery 24 for providing a power source; a power management chip 25; for drawing power from the battery 24 and controlling the voltage and current of the display screen, the processor 21, the memory device 22, and the radio frequency device 23. The sounding position corresponding to the filter capacitor 20 is mainly located near the power management chip 25 and the radio frequency device 23, the fluctuation of the power near the power management chip 25 and the radio frequency device 23 is the largest, the amplitude of the capacitor vibration is the largest, and the generated noise is the most obvious.

It should be noted that fig. 1c is a schematic diagram of a motherboard structure, and the motherboard in the present application may further include other components, for example, the filter capacitor may also be disposed near the other components. Meanwhile, the components are also connected in a related mode, and the specific composition of the main plate structure and the connection mode among the components are not limited in the application.

In an exemplary embodiment, fig. 2 is a flowchart illustrating a noise reduction method provided herein. The method can be applied to the condition of weakening audio noise caused by the piezoelectric effect of the capacitor on the mainboard. Accordingly, as shown in fig. 2, the present application provides a noise reduction method, which includes S110, S120, and S130.

S110, confirming the sounding position of the main board supporting piece; wherein the sound emission position comprises at least one filter capacitor.

The sounding position is the position where the filter capacitor on the PCB mainboard supporting piece generates audio noise.

Because the output power of the whole machine on the PCB mainboard is gradually improved, the power voltage is easy to fluctuate. The fluctuation of voltage leads to the mechanical vibration of filter capacitor, and then drives the vibration of PCB mainboard, and the frequency of vibration just falls into the human ear and receives the scope to cause the audio noise. Therefore, at least one filter capacitor is typically included at the sound emitting position of the PCB main board support. Before noise reduction processing is carried out on a filter capacitor of a PCB mainboard, a sound production position on a PCB mainboard supporting piece needs to be confirmed firstly.

And S120, covering a liquid resistance-capacitance layer on the surface of the filter capacitor at the sounding position.

The liquid resistance-capacitance layer comprises a liquid resistance-capacitance material, and is used for reducing noise generated by the filter capacitor at the sounding position.

Correspondingly, after the sounding position on the PCB mainboard supporting piece is confirmed, the filter capacitor at the sounding position can be covered by the liquid resistance-capacitance material to form a liquid resistance-capacitance layer.

S130, solidifying the liquid resistance-capacitance layer.

Correspondingly, after the liquid resistance-capacitance layer is covered on the surface of the filter capacitor, the liquid resistance-capacitance layer can be solidified.

Therefore, the noise reduction method does not need to change the layout of devices on a PCB mainboard and increase the overall height of the capacitor by using the squeaking-preventing capacitor, so that the overall thickness of the mainboard is not influenced, the audio noise caused by the filter capacitor can be simply and effectively reduced, and the purpose of noise reduction is achieved.

This application is through confirming mainboard support piece's vocal position to adopt liquid resistance-capacitance layer to fall the processing of making an uproar to filter capacitor in vocal position department, solved the technical problem of the audio frequency noise that capacitor piezoelectric effect causes on the mainboard effectively, thereby cut down the audio frequency noise that capacitor piezoelectric effect causes on the mainboard.

In one example, the covering of the surface of the filter capacitor at the sounding position with a liquid resistance-capacitance layer may include: and coating the surface of the filter capacitor at the sounding position by the liquid resistance-capacitance material to form a liquid resistance-capacitance layer.

Specifically, the liquid resistance-capacitance layer can be generated by coating the surface of the filter capacitor with a liquid resistance-capacitance material. Alternatively, the coating method may be dipping, spraying, spot coating, spin coating, or the like, and the application does not limit the specific type of the coating method.

In one example, the covering of the surface of the filter capacitor at the sounding position with a liquid resistance-capacitance layer may include: and under the condition that the sounding position comprises a plurality of filter capacitors, connecting the liquid resistance-capacitance layers covered by all the filter capacitors at the sounding position into one or more pieces.

In this application, if there are a plurality of filter capacitors in the vocal position department, can utilize liquid resistance-capacitance layer to cover to whole filter capacitors in this region. Optionally, a liquid rc layer may be used to cover all the filter capacitors. Alternatively, it is also possible to cover all the filter capacitors with a plurality of liquid rc layers, for example, one liquid rc layer covers 2 or 3 filter capacitors. Correspondingly, if the sounding positions are multiple, the liquid resistance-capacitance layers can be used for respectively covering the filter capacitors at the sounding positions.

In one example, the curing the liquid resistive-capacitive layer may include: and heating the liquid resistance-capacitance layer according to a preset heating condition.

In one example, the curing the liquid resistive-capacitive layer may include: and carrying out illumination treatment on the liquid resistance-capacitance layer according to a preset illumination condition.

Wherein the set illumination intensity can be an illumination intensity set according to the damping characteristic requirement for noise reduction, such as 60mW/cm²And the like. The second set time may be a time set according to a damping characteristic requirement for achieving the noise reduction purpose, such as 10 minutes or the like. The embodiment of the present application does not limit the specific values of the set illumination intensity and the second set time.

In one example, the confirming the sounding position of the main board support may include: and scanning the mainboard through audio test equipment to obtain the sounding position.

The audio test device may be a device for testing audio noise, such as a stethoscope or a professional audio tester, and as long as the device for testing audio noise can be the audio test device of the present application, the present application does not limit the specific type of the audio test device.

In the application, the sounding position on the PCB mainboard supporting piece can be confirmed through an auxiliary audio test means. Illustratively, the general orientation of the sound on the PCB motherboard support may be quickly and efficiently confirmed by the stethoscope. Or, a professional audio tester can be used for scanning the main board area, searching the area with the most obvious noise as the sounding position, and marking the sounding position in sequence.

In one example, the liquid resistance-capacitance material comprises glue, and the hardness of the glue after solidification is within a preset hardness interval threshold range.

In an exemplary embodiment, the present application further provides a terminal, and fig. 3 is a schematic structural diagram of a terminal provided in the present application. For the content of the present embodiment that has not been detailed, reference may be made to the above embodiments, which are not described herein again.

As shown in fig. 3, the terminal provided by the present application may include: a display screen 26 and a main board as described in the above embodiments.

The above description is only exemplary embodiments of the present application, and is not intended to limit the scope of the present application.

It will be clear to a person skilled in the art that the term user terminal covers any suitable type of wireless user equipment, such as a mobile phone, a portable data processing device, a portable web browser or a car mounted mobile station.

In general, the various embodiments of the application may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the application is not limited thereto.

Embodiments of the application may be implemented by a data processor of a mobile device executing computer program instructions, for example in a processor entity, or by hardware, or by a combination of software and hardware. The computer program instructions may be assembly instructions, Instruction Set Architecture (ISA) instructions, machine related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages.

Any logic flow block diagrams in the figures of this application may represent program steps, or may represent interconnected logic circuits, modules, and functions, or may represent a combination of program steps and logic circuits, modules, and functions. The computer program may be stored on a memory. The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as, but not limited to, Read Only Memory (ROM), Random Access Memory (RAM), optical storage devices and systems (digital versatile disks, DVDs, or CD discs), etc. The computer readable medium may include a non-transitory storage medium. The data processor may be of any type suitable to the local technical environment, such as but not limited to general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), programmable logic devices (FGPAs), and processors based on a multi-core processor architecture.

The foregoing has provided by way of exemplary and non-limiting examples a detailed description of exemplary embodiments of the present application. Various modifications and adaptations to the foregoing embodiments may become apparent to those skilled in the relevant arts in view of the following drawings and the appended claims without departing from the scope of the invention. Therefore, the proper scope of the invention is to be determined according to the claims.

Claims

1. A mainboard is characterized by comprising a support piece and a filter capacitor; wherein:

2. The motherboard of claim 1, wherein the liquid RC layer is formed by coating a surface of the filter capacitor with the liquid RC material.

3. A main board according to claim 2, wherein in a case where a plurality of the filter capacitors are included at the sound emission site, the number of liquid resistance-capacitance layers on the surfaces of all the filter capacitors at the sound emission site is at least 1.

4. The motherboard of claim 1, wherein the liquid resistive-capacitive layer is cured in a manner comprising:

and heating the liquid resistance-capacitance layer according to a preset heating condition.

5. The motherboard of claim 4, wherein the preset heating conditions comprise:

the heating temperature reaches the set temperature, and/or the heating time reaches the first set time.

6. The motherboard of claim 1, wherein the liquid resistive-capacitive layer is cured in a manner comprising:

and carrying out illumination treatment on the liquid resistance-capacitance layer according to a preset illumination condition.

7. The motherboard of claim 6, wherein the preset lighting conditions comprise:

the illumination intensity reaches the set illumination intensity, and/or the illumination time reaches a second set time.

8. The main board according to any one of claims 1 to 7, wherein the liquid resistive-capacitive material comprises glue, and the hardness of the glue after curing is within a threshold range of a preset hardness interval.

9. A method of noise reduction, comprising:

and solidifying the liquid resistance-capacitance layer.

10. The method of claim 9, wherein: the surface of the filter capacitor at the sounding position is covered with a liquid resistance-capacitance layer, and the liquid resistance-capacitance layer comprises:

and coating the surface of the filter capacitor at the sounding position by the liquid resistance-capacitance material to form a liquid resistance-capacitance layer.

11. The method of claim 10, wherein covering the surface of the filter capacitor at the sound emission location with a liquid RC layer comprises:

and under the condition that the sounding position comprises a plurality of filter capacitors, connecting the liquid resistance-capacitance layers covered by all the filter capacitors at the sounding position into one or more pieces.

12. The method of claim 9, wherein curing the liquid resistive-capacitive layer comprises:

13. The method of claim 12, wherein the preset heating conditions comprise:

14. The method of claim 9, wherein curing the liquid resistive-capacitive layer comprises:

15. The method of claim 14, wherein the preset lighting conditions comprise:

16. The method of claim 9, wherein the confirming the sound emitting position of the motherboard supporting member comprises:

and scanning the mainboard through audio test equipment to obtain the sounding position.

17. The method according to any one of claims 9-16, wherein the liquid resistance-capacitance material comprises glue, and the hardness of the glue after curing is within a threshold range of a preset hardness interval.

18. A terminal, characterized in that it comprises a display and a main board according to any one of claims 1-8.