Preparation process of multifunctional SMD active piezoelectric buzzer

Abstract

The application belongs to a sound generating component in the field of electroacoustics, and particularly relates to a preparation process of a multifunctional SMD active piezoelectric buzzer, which comprises a shell upper cover, a high-temperature-resistant buzzer sheet, a micro-encapsulated special piezoelectric buzzer driving integrated circuit, two micro-tower springs, a metal lead frame and a shell base, and is characterized in that the high-temperature-resistant buzzer sheet is installed at the step of the shell upper cover and is fixed by silicone sealing, an inside of the shell upper cover is provided with a sound hole, a sound cavity is formed between the high-temperature-resistant buzzer sheet and the shell upper cover, the metal lead frame and the shell base are integrally molded, a top of the metal lead frame and the shell base forms a plane, a connecting rib of the metal lead frame is extended to the outside of the shell base and is bent downward to become a product lead pin, and the device solves the problems of large volume and complex structure of the current multifunctional active SMD piezoelectric buzzer, thereby leading to low assembly efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to a sound generating component in the field of electroacoustics, and particularly relates to a preparation process of a multifunctional SMD active piezoelectric buzzer. BACKGROUND

[0002] The SMD piezoelectric buzzer is an electroacoustic component, has low driving power consumption, good reliability, and is widely used in various portable household health products, instruments and meters, various office equipment, automobile electronics, digital products, electronic door locks, smart home, Internet of Things and the like to play a prompting and warning role.

[0003] At present, the mainstream product on the market is mainly a passive SMD piezoelectric buzzer, the minimum size of which has developed to 9*9*1.8mm, and the structure and manufacturing process have been very mature. The current manufacturing method of the active SMD piezoelectric buzzer is to assemble an oscillation driving circuit composed of electronic components or integrated circuits on a PCB board. The external pin usually adopts a scheme of installing metal pins on both sides of the shell, and performing tin soldering with the circuit board to form two pins of a power supply positive electrode VDD and a power supply negative electrode VSS. The disadvantage of this implementation method is that the product size is limited by the electronic components and the PCB board, the assembly process is complicated, the manual operation station is large, the efficiency is low, the product function is single, and the sound pressure is low. SUMMARY

[0004] The purpose of the present application is to provide a preparation process of a multifunctional SMD active piezoelectric buzzer to solve the problems raised in the background art.

[0005] In order to solve the above technical problems, the present application provides the following technical scheme: a preparation process of a multifunctional SMD active piezoelectric buzzer, comprising a shell upper cover, a high-temperature-resistant buzzer sheet, a micro-encapsulated special piezoelectric buzzer driving integrated circuit, two micro-tower springs, a metal lead frame and a shell base.

[0006] The preparation process of the buzzer comprises the following steps:

[0007] Step S1, the high-temperature-resistant buzzer sheet is installed at the step of the shell upper cover and is fixed by silicone sealing;

[0008] Step S2, the metal lead frame and the shell base are formed by one-piece molding, the connecting ribs of the metal lead frame are extended to the outside of the shell base, and are bent downward to become product pins. Tin paste is printed on the surface of the metal lead frame, and the pins of the micro-encapsulated special piezoelectric buzzer driving integrated circuit and the two micro-tower springs are bonded to the surface of the metal lead frame through the tin paste, and then are electrically connected by heating and melting and solidification.

[0009] Step S3, the shell cover and the shell base are bonded by glue heating solidification, at this time, the two micro-tower springs are in contact with the two poles of the high-temperature-resistant buzzing sheet respectively, and an electrical connection is generated;

[0010] Step S4, the extension part of the connecting rib of the metal lead frame is cut and bent by a mold, forming the external pins of the buzzer, and four pins of power positive VDD, power negative VSS, enable end EN and DIN signal input end are arranged on the outside of the buzzer respectively.

[0011] The application further illustrates that the step S1 comprises:

[0012] Step S1.1, LCP engineering plastic with high temperature resistance of 300 degrees is used to form the shell cover by molding, and two steps are formed inside;

[0013] Step S1.2, a layer of anaerobic silicone is applied on the first step by a glue machine, then the high-temperature-resistant buzzing sheet is placed on the first step for sealing and fixing, and a rectangular sound hole is formed on the top of the shell cover during molding, so that a resonance sound cavity is formed between the high-temperature-resistant buzzing sheet and the inside of the shell cover.

[0014] The application further illustrates that the step S2 comprises:

[0015] Step S2.1, copper or brass or copper alloy strip with a thickness of 0.1-0.15 mm is used to form the metal lead frame by etching process or stamping process;

[0016] Step S2.2, the metal lead frame is fully plated with tin by integrated circuit frame electroplating method;

[0017] Step S2.3, the metal lead frame is used as an insert to form the shell base by LCP engineering plastic integral molding, so that the metal lead frame and the top of the shell base form a plane, and the connecting rib of the metal lead frame is extended to the outside of the shell base by several millimeters in length.

[0018] The application further illustrates that the step S3 comprises:

[0019] Step S3.1, tin paste is selectively printed on the metal lead frame part of the shell base surface by SMT assembly process, and the pins of the special piezoelectric buzzer drive integrated circuit of the micro package and the bottom of the two micro-tower springs are precisely positioned and bonded with the tin paste part, and are fused and solidified by reflow soldering furnace, so as to form an electrical connection;

[0020] Step S3.2, high-temperature-resistant glue is applied around the second step of the shell cover, and the shell base is embedded and flattened by positioning, and is bonded into an integral whole by heating solidification;

[0021] Step S3.3, after the shell cover is bonded with the shell base, two metal tower springs fixed on the metal lead frame part on the surface of the shell base form two drive output pins VO1 and V02 of the electric buzzer drive integrated circuit, which correspond to two poles of the high-temperature-resistant buzzer sheet 2 respectively, so as to produce close contact and electrical connection.

[0022] The application further discloses that the step S4 comprises:

[0023] Step S4.1, the extended part of the metal lead frame connecting rib embedded in the shell base integrally through mold pressing is cut by a mold to form four external pins;

[0024] Step S4.2, the four external pins correspond to the power supply positive pole VDD, the power supply negative pole VSS, the enable end EN and the DIN signal input end of the buzzer respectively, and the four pins are formed into J-shaped pins through mold forming.

[0025] The application further discloses that in the steps S1 to S4, a conventional passive SMD piezoelectric buzzer injection molding process is combined with a precise electronic assembly SMT process.

[0026] The application further discloses that in the steps S1 to S4, the multifunctional SMD active piezoelectric buzzer is directly connected with a single-chip microcomputer to realize communication.

[0027] Compared with the prior art, the application has the beneficial effects that: the conventional passive SMD piezoelectric buzzer injection molding process is combined with the precise electronic assembly SMT process; the special piezoelectric buzzer drive integrated circuit is electrically connected with the lead frame, without the need of metal wire connection and manual assembly, so that the production efficiency and the integration effect of the product are greatly improved, the production cost is reduced, the product reliability is improved, the buzzer output sound pressure is improved through the special integrated circuit, the buzzer can be directly connected with the single-chip microcomputer to communicate, various sound effects can be generated through the software algorithm, so as to meet the personalized needs of modern different electronic products and customers. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings are included to provide a further understanding of the application and constitute a part of the specification, illustrate the application and are used to explain the application, and do not constitute a limitation on the application. In the drawings:

[0029] Figure 1 is a structural section view of the application;

[0030] Figure 2 is a schematic view of a buzzer sheet of the application;

[0031] Figure 3 is a schematic view of a drive integrated circuit package of the application;

[0032] Figure 4 is the connection structure diagram of the driving integrated circuit, metal hourglass spring and base planar lead frame of the application;

[0033] Figure 5 is the application electric diagram of the application;

[0034] In the figure: 1, the upper cover of the shell; 2, the high-temperature-resistant buzzing sheet; 3, the micro-encapsulated special piezoelectric buzzer driving integrated circuit; 4, the micro hourglass spring; 5, the metal lead frame; 6, the shell base. DETAILED DESCRIPTION

[0035] The technical solutions of the application will be further and non-restrictively described in detail below in combination with the preferred embodiments and the drawings. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all the other embodiments obtained by a person of ordinary skill in the art without creative work belong to the protection scope of the application.

[0036] Please refer to Figures 1-5 The application provides the technical solution of the multifunctional SMD active piezoelectric buzzer preparation process, which includes the upper cover of the shell 1, the high-temperature-resistant buzzing sheet 2, the micro-encapsulated special piezoelectric buzzer driving integrated circuit 3, two micro hourglass springs 4, the metal lead frame 5 and the shell base 6.

[0037] The preparation process of the buzzer includes the following steps:

[0038] Step S1, the high-temperature-resistant buzzing sheet 2 is installed at the step of the upper cover of the shell 1 and is fixed by silicone sealing;

[0039] Step S2, the metal lead frame 5 and the shell base 6 are formed by one-piece molding, the connecting rib of the metal lead frame 5 is extended to the outside of the shell base 6 and is bent downward to become the product pin, the tin paste is printed on the surface of the metal lead frame 5, the pin of the micro-encapsulated special piezoelectric buzzer driving integrated circuit 3 and the two micro hourglass springs 4 are bonded with the surface of the metal lead frame 5 through the tin paste, and then the electrical connection is formed by heating and melting solidification;

[0040] Step S3, the upper cover of the shell 1 and the shell base 6 are bonded by glue heating solidification, at this time, the two micro hourglass springs 4 respectively contact with the two poles of the high-temperature-resistant buzzing sheet 2 and generate electrical connection;

[0041] Step S4, the extension part of the connecting rib of the metal lead frame 5 is cut and bent by the mold to form the external pin of the buzzer, and the power positive VDD, the power negative VSS, the enable end EN and the DIN signal input end four pins are respectively arranged on the outside of the buzzer.

[0042] Step S1 includes:

[0043] Step S1.1, using high-temperature-resistant 300-degree LCP engineering plastics to form the shell cover 1 by molding, and two steps are formed inside;

[0044] Step S1.2, at the first step, use a glue machine to apply a layer of anaerobic silicone, then place the high-temperature-resistant buzzer sheet 2 at the first step for sealing and fixing, and set a rectangular sound hole on the top of the shell cover 1 when molding, so that the high-temperature-resistant buzzer sheet 2 and the inside of the shell cover 1 form a resonant sound cavity.

[0045] Step S2 includes:

[0046] Step S2.1, using 0.1-0.15mm thick copper or brass or copper alloy strip to form a metal lead frame 5 by etching process or stamping process;

[0047] Step S2.2, then fully tin the metal lead frame 5 by integrated circuit frame electroplating;

[0048] Step S2.3, the shell base 6 uses LCP engineering plastics to form a metal lead frame 5 as an insert, so that the metal lead frame 5 and the top of the shell base 6 form a plane, and the connecting ribs of the metal lead frame 5 are extended to the outside of the shell base 6 by several millimeters in length.

[0049] Step S3 includes:

[0050] Step S3.1, using SMT assembly process to selectively print tin paste on the surface of the shell base 6 at the metal lead frame 5 part, and precisely aligning and bonding the pins of the micro-encapsulated special piezoelectric buzzer drive integrated circuit 3 and the bottom of the two micro-tower springs 4 with the tin paste part, and then melting and solidifying through reflow soldering furnace, thereby forming an electrical connection;

[0051] Step S3.2, apply high-temperature-resistant glue around the second step of the shell cover 2, and embed the shell base 6 in place, and then heat and bond to form an integral whole;

[0052] Step S3.3, after the shell cover 1 and the shell base 6 are bonded, the two metal tower springs 4 at the metal lead frame 5 part on the surface of the shell base 6 form two drive output pins VO1 and V02 of the electric buzzer drive integrated circuit, which correspond to the two poles of the high-temperature-resistant buzzer sheet 2 respectively, thereby producing close contact and electrical connection.

[0053] Step S4 includes:

[0054] Step S4.1, the extension of the coupling rib of the metal lead frame 5 integrated with the shell base 6 by die embedding is cut to form 4 external pins by a die;

[0055] Step S4.2, the 4 external pins correspond to the positive power supply VDD, the negative power supply VSS, the enable end EN and the DIN signal input end of the buzzer respectively, and the 4 pins are formed into J-shaped pins by a die.

[0056] In steps S1 to S4, the conventional passive SMD piezoelectric buzzer injection molding process is combined with the precise electronic assembly SMT process.

[0057] The special piezoelectric buzzer driving integrated circuit is electrically connected with the lead frame, without the need for metal wire connection and manual assembly, greatly improving the production efficiency and the integration effect of the product, reducing the production cost, improving the product reliability, and through the special integrated circuit, the buzzer output sound pressure is improved, which can be directly connected with a single-chip microcomputer for communication, and various sound effects can be generated through software algorithm to meet the needs of different electronic products and personalized needs of customers.

[0058] In steps S1 to S4, the multifunctional SMD active piezoelectric buzzer is directly connected with a single-chip microcomputer to realize communication.

[0059] Various sound effects can be realized through software algorithm, the function is multiple, the output sound pressure is high, the manufacturing process is simple, automatic assembly can be realized, the manufacturing cost is greatly reduced, and the product is more easily accepted by the market.

[0060] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the present application.

[0061] Finally, it should be pointed out that: the above examples are only used to illustrate the technical solutions of the present application, and are not limited thereto. Although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing examples, or make equivalent replacement to part of the technical features, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A multifunctional SMD active piezoelectric buzzer preparation process, comprising a shell upper cover (1), a high-temperature-resistant buzzer sheet (2), a micro-encapsulated special piezoelectric buzzer drive integrated circuit (3), two micro-tower springs (4), a metal lead frame (5), and a shell base (6); The preparation process of the buzzer comprises the following steps: Step S1, install the high-temperature-resistant buzzer sheet (2) at the step of the shell upper cover (1), and seal and fix it by silica gel; Step S2, form the metal lead frame (5) and the shell base (6) by one-step molding, and extend the connecting rib of the metal lead frame (5) to the outside of the shell base (6) and bend it downward to become the product lead, print tin paste on the surface of the metal lead frame (5), and bond the pins of the micro-encapsulated special piezoelectric buzzer drive integrated circuit (3) and the two micro-tower springs (4) to the surface of the metal lead frame (5) through tin paste, and then form electrical connection by heating and melting and solidification; Step S3, bond the shell upper cover (1) and the shell base (6) by glue heating and solidification, at this time the two micro-tower springs (4) are in contact with the two poles of the high-temperature-resistant buzzer sheet (2) respectively, and electrical connection is generated; Step S4, cut and bend the extension part of the connecting rib of the metal lead frame (5) by a mold to form the external lead of the buzzer, and four leads of power positive VDD, power negative VSS, enable end EN, and DIN signal input end are arranged outside the buzzer respectively; The step S3 comprises: Step S3.1, selectively print tin paste on the part of the metal lead frame (5) on the surface of the shell base (6) by SMT assembly process, and accurately position and bond the pins of the micro-encapsulated special piezoelectric buzzer drive integrated circuit (3) and the bottom of the two micro-tower springs (4) to the tin paste part, and then form electrical connection by reflow soldering furnace melting and solidification; Step S3.2, coat the high-temperature-resistant glue around the second step of the shell upper cover (1), and embed the shell base (6) in place, and bond them into one by heating and solidification; Step S3.3, after the shell upper cover (1) and the shell base (6) are bonded, the two metal tower springs (4) on the part of the metal lead frame (5) fixed on the surface of the shell base (6) form two drive output pins VO1 and V02 of the electric buzzer drive integrated circuit, which correspond to the two poles of the high-temperature-resistant buzzer sheet (2) respectively, so as to generate close contact and electrical connection.

2. The process for the preparation of multifunctional SMD active piezoelectric buzzer according to claim 1, characterized in that: The step S1 comprises: Step S1.1, use LCP engineering plastic with high-temperature resistance of 300 degrees to form the shell upper cover (1) by molding, and form two steps inside at the same time; Step S1.2, coat a layer of anaerobic silicone on the first step by a glue machine, then place the high-temperature-resistant buzzer sheet (2) on the first step for sealing and fixing, and set a rectangular sound hole on the top of the shell upper cover (1) when molding, so as to form a resonance sound cavity between the high-temperature-resistant buzzer sheet (2) and the inside of the shell upper cover (1).

3. The process for the preparation of multifunctional SMD active piezoelectric buzzer as claimed in claim 1, wherein: The step S2 comprises: Step S2.1, a copper or brass or copper alloy strip with thickness of 0.1-0.15 mm is used to form the metal lead frame (5) by etching process or stamping process; Step S2.2, the metal lead frame (5) is then fully plated with tin by integrated circuit frame electroplating method; Step S2.3, the metal lead frame (5) is integrally molded with the LCP engineering plastic as an insert in the housing base (6), so that the metal lead frame (5) forms a plane with the top of the housing base (6), and the connecting ribs of the metal lead frame (5) are extended by several millimeters outside the housing base (6).

4. The process for manufacturing a multi-functional SMD active piezoelectric buzzer according to claim 1, wherein: The step S4 includes: Step S4.1, the extended part of the connecting rib of the metal lead frame (5) integrally embedded in the housing base (6) by molding is cut by a mold to form four external pins; Step S4.2, the four external pins correspond to the positive power supply VDD, negative power supply VSS, enable end EN and DIN signal input end of the buzzer respectively, and the four pins are formed into J-shaped pins by mold forming.

5. The process for manufacturing multi-functional SMD active piezoelectric buzzer according to claim 1, wherein: In the steps S1 to S4, the conventional passive SMD piezoelectric buzzer injection molding process is combined with the precise electronic assembly SMT process.

6. The process for the preparation of multifunctional SMD active piezoelectric buzzer according to claim 1, characterized in that: In the steps S1 to S4, the multifunctional SMD active piezoelectric buzzer is directly connected with the single-chip microcomputer to realize communication.

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