Radio frequency device and preparation method thereof

Abstract

The invention provides a radio frequency device and a preparation method thereof. The radio frequency device comprises a shell, wherein the shell comprises a metal heat sink, a lead frame and a cover plate from bottom to top in sequence; the lead frame is bonded and fixed on the front surface of the metal heat sink; the cover plate is bonded and fixed at the top end of the lead frame; the chip is arranged in the shell and is welded and fixed on the front surface of the metal heat sink; the lead is connected with the metal pin of the chip and the metal pin of the lead frame; the sealing glue is poured between the metal heat sink and the lead frame and covers the welding positions of the metal pins of the chip, the lead, the metal pins of the lead frame, the chip and the metal heat sink, and the sealing glue is formed at the position, located in the shell, of the metal heat sink. The technical problems that a traditional radio frequency device is high in cost and insufficient in electrical performance and heat conduction capacity are solved.

Description

Technical Field

[0001] The present application relates to the technical field of radio frequency devices, and in particular, to a radio frequency device and a method for manufacturing the same. Background Art

[0002] OMP (Over-Molded Plastic Package) packaging, Chinese name is over-molded plastic packaging. The chip is accurately placed on the packaging substrate through high-quality solder to ensure accurate positioning. Then the chip is connected to the package pins using wire bonding technology to achieve circuit conduction. Finally, the product is injection molded with epoxy molding compound. The step of injection molding the product with epoxy molding compound can not only effectively protect the chip from the influence of the external environment, but also provide reliable mechanical support for the entire product, ensuring its stable operation in various application scenarios.

[0003] Figure 1 This is a schematic diagram of a product using traditional OMP packaging. OMP packaging uses a high-temperature and high-pressure mold to inject epoxy resin molding compound into the frame to achieve high mechanical strength and low material cost injection molding packaging products. Therefore, in order to ensure the mechanical strength and processing capabilities of OMP packaging products, the thermoelectric functionality of the molding compound is usually weak and difficult to improve. For example, the most common Panasonic CV series products and Sumitomo EME series on the market have thermal conductivity less than 1W / (m·K), and the dielectric loss exceeds 0.01. In addition, the stamping, riveting, injection molding and other jigs used in OMP packaging are highly customized and too expensive. In the face of products of different sizes and shapes, a corresponding set of jigs is required. The investment cost of a set of jigs exceeds one million, which is not suitable for the current development trend of PA (Power Amplifier) ​​devices with diversified sizes and shapes. Among them, WB is the abbreviation of Wire Bonding in English, which is wire bonding in Chinese; DB is the abbreviation of Die Bonding in English, which is chip welding in Chinese.

[0004] Figure 2This is a schematic diagram of a product packaged using a traditional cavity packaging solution. The cavity is formed by bonding the substrate and the outer frame cavity, and then the chip and other components are fixed by welding or adhesive. The chip is connected to the pin through wire bonding, and finally the cover is sealed with high-performance sealing glue to ensure the cavity sealing and reduce the intrusion of air and moisture. The cavity is sealed by solder or glue, which is a quasi-airtight level. During long-term use, air and moisture will inevitably enter the cavity, causing oxidation and corrosion risks to the device. In order to reduce the damage to the device caused by air and moisture entering the cavity, all metals in the cavity, including the substrate and frame, need to be gold-plated or silver-plated to form an electroplating layer. At the same time, wire bonding and welding are mostly packaged with gold and silver solder and wire, which leads to extremely high manufacturing costs per cavity package.

[0005] Therefore, the cost of traditional RF devices is relatively high and cannot meet the development trend of widespread use of RF devices.

[0006] The above information disclosed in the background section is only for enhancing understanding of the background of the present application and therefore it may contain information that does not form the prior art known to a person of ordinary skill in the art. Summary of the invention

[0007] The present application provides a radio frequency device and a method for preparing the same, in order to solve the technical problems of high cost, insufficient electrical performance and insufficient thermal conductivity of traditional radio frequency devices.

[0008] The present application provides a radio frequency device, including:

[0009] A three-section structured housing, wherein the housing comprises a metal heat sink, a lead frame and a cover plate from bottom to top; the lead frame is bonded and fixed to the front of the metal heat sink, and the cover plate is bonded and fixed to the top of the lead frame;

[0010] A chip disposed in the housing is welded and fixed on the front side of the metal heat sink;

[0011] A lead wire is disposed in the housing, the lead wire connecting a metal pin of the chip and a metal pin of the lead frame;

[0012] A sealant is formed in the housing, wherein the sealant is formed by pouring the sealant between the metal heat sink and the lead frame and covering the chip, the lead wires and the metal pins of the lead frame;

[0013] Among them, the sealing of the chip and the lead is a double-layer sealing, the first layer of sealing is achieved by the first adhesive for bonding and fixing the lead frame and the metal heat sink, and the second adhesive for bonding and fixing the cover plate and the top of the lead frame; the second layer of sealing is achieved by the sealant.

[0014] This application also provides the following technical solutions:

[0015] A method for preparing a radio frequency device comprises the following steps:

[0016] Adhere and fix the lead frame to the front side of the metal heat sink;

[0017] Soldering and fixing a chip on the front side of the metal heat sink, with the chip being located in the space surrounded by the lead frame;

[0018] Connecting the metal pins of the chip and the metal pins of the lead frame with wires to form leads;

[0019] The sealing glue is poured between the metal heat sink and the lead frame and covers the metal pins and leads of the chip, the metal pins of the lead frame, the welding position of the chip and the metal heat sink, and the position of the metal heat sink in the housing to form the sealant;

[0020] The cover plate is bonded and fixed on the top of the lead frame.

[0021] Due to the adoption of the above technical solution, this application has the following technical effects:

[0022] First aspect: a three-section structured housing is used. Each of the metal heat sink 1, the lead frame 2, and the cover plate 6 has a relatively simple structure and is universal, so that the same set of jigs can be used for the production of various specifications of the RF devices of the present application, greatly reducing the cost of the RF products of the present application.

[0023] The second aspect: double-layer sealing.

[0024] The first layer of sealing is achieved by the first adhesive 81 for bonding and fixing the lead frame 2 and the metal heat sink 1, and the second adhesive 82 for bonding and fixing the cover plate 6 and the top of the lead frame 2. That is, the first layer of sealing is the sealing at the shell. The first layer of sealing can isolate most of the air and moisture outside the shell.

[0025] The second layer of sealing is a sealing structure formed by pouring potting glue between the metal heat sink and the lead frame and covering the metal pins of the chip, the leads and the lead frame. That is, the second layer of sealing in the shell is directly aimed at the metal pins of the chip, the leads, the metal pins of the lead frame, the position where the chip and the metal heat sink are welded, and the position where the metal heat sink is located in the shell. The second layer of sealing is a seal directly aimed at the metal pins of the chip, the leads, the metal pins of the lead frame, the position where the chip and the metal heat sink are welded, and the position where the metal heat sink is located in the shell, and is achieved by the sealant formed by covering the metal pins of the chip, the leads and the lead frame. Even if a small amount of air and moisture enters the shell, the second layer of sealing will prevent the air and moisture from contacting the metal pins of the chip, the leads and the lead frame. Therefore, the radio frequency device of the present application has extremely high sealing. It is no longer necessary to use precious metal components such as gold and silver for the metal pins of the chip, the leads, the metal pins of the lead frame, the position where the chip and the metal heat sink are welded, and the position where the metal heat sink is located in the shell. Related to background technology Figure 2 Compared with the previous solution, the cost is greatly reduced.

[0026] Third aspect: quick assembly. The lead frame 2 and the metal heat sink 1 are bonded and fixed, and the cover plate 6 and the top of the lead frame 2 are bonded and fixed, so that the assembly of the housing is quick and convenient during the assembly process.

[0027] The chip is welded and fixed on the front side of the metal heat sink, the leads are connected to the metal pins of the chip and the metal pins of the lead frame, and the potting glue is poured to form a sealant. Each process is relatively simple.

[0028] Fourth aspect: good thermoelectric performance and background technology Figure 1 Compared with the solution, since the potting glue operation is easy and does not need to play a supporting role, sealing materials with higher thermal conductivity and lower dielectric loss can be used, thereby improving the thermoelectric performance of the device.

[0029] In summary, the structure of the RF device of the present application is simple and universal, so that the jig for producing the RF device of the present application is universal, and the manufacture of the RF device of the present application is quick, convenient and low-cost, and the thermoelectric performance is better. The double-layer sealed structural feature of the RF device of the present application also makes the RF device of the present application extremely airtight, and thus has a high resistance to oxidation and corrosion, thereby making the RF device more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0031] Figure 1A schematic diagram of a product using traditional OMP packaging;

[0032] Figure 2 A schematic diagram of a product packaged using a traditional cavity packaging solution;

[0033] Figure 3 A schematic diagram of a radio frequency device of the present application.

[0034] Reference numerals:

[0035] This application:

[0036] Metal heat sink 1, lead frame 2, step 21, chip 3, lead 4, sealant 5,

[0037] Cover plate 6 , sintered copper 7 , first adhesive 81 , second adhesive 82 . DETAILED DESCRIPTION

[0038] In order to make the technical solutions and advantages of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0039] Embodiment 1

[0040] like Figure 3 As shown, the radio frequency device of the present application includes:

[0041] A metal heat sink 1 and a lead frame 2, wherein the lead frame 2 is bonded and fixed to the front side of the metal heat sink 1;

[0042] The chip 3 is fixed on the front side of the metal heat sink 1 by welding and is located in the space enclosed by the metal heat sink 1 and the lead frame 2;

[0043] Lead wires 4, the lead wires 4 connecting metal pins of the chip 3 and metal pins of the lead frame 2;

[0044] Sealant 5, the sealing glue is poured into the space enclosed by the metal heat sink 1 and the lead frame 2 and covers the chip 3, the lead 4 and the metal pins of the lead frame to form the sealant 5;

[0045] The cover plate 6 is bonded and fixed on the top of the lead frame 2 .

[0046] The RF device of the present application has a shell with a three-section structure, and the shell comprises a metal heat sink 1, a lead frame 2 and a cover plate 6 from bottom to top; the lead frame 2 is bonded and fixed to the front side of the metal heat sink 1, and the cover plate 6 is bonded and fixed to the top of the lead frame 2.

[0047] The chip 3, the lead 4 and the sealant 5 are located in the shell. The chip 3 is located in the shell and is welded and fixed on the front side of the metal heat sink 1. The lead 4 connects the metal pins of the chip and the metal pins of the lead frame. The sealant 5 covers the entire chip 3 and the lead 4.

[0048] The advantages of the radio frequency device of this application are:

[0049] First aspect: a three-section structured housing is used. Each of the metal heat sink 1, the lead frame 2, and the cover plate 6 has a relatively simple structure and is universal, so that the same set of jigs can be used for the production of various specifications of the RF devices of the present application, greatly reducing the cost of the RF products of the present application.

[0050] The second aspect: double-layer sealing.

[0051] The first layer of sealing is achieved by the first adhesive 81 for bonding and fixing the lead frame 2 and the metal heat sink 1, and the second adhesive 82 for bonding and fixing the cover plate 6 and the top of the lead frame 2. That is, the first layer of sealing is the sealing at the shell. The first layer of sealing can isolate most of the air and moisture outside the shell.

[0052] The second layer of sealing is formed by pouring potting glue between the metal heat sink and the lead frame and covering the metal pins, leads, metal pins of the lead frame, the position where the chip and the metal heat sink are welded, and the position where the metal heat sink is located in the shell to form the sealing structure. That is, the second layer of sealing directly targets the metal pins, leads, metal pins of the lead frame, the position where the chip and the metal heat sink are welded, and the position where the metal heat sink is located in the shell. The second layer of sealing is directly aimed at the metal pins, leads, metal pins of the lead frame, the position where the chip and the metal heat sink are welded, and the position where the metal heat sink is located in the shell. It is achieved by covering the metal pins, leads, metal pins of the lead frame, the position where the chip and the metal heat sink are welded, and the position where the metal heat sink is located in the shell. Even if a small amount of air and moisture enters the shell, the second layer of sealing will prevent air and moisture from contacting the metal pins, leads, metal pins of the lead frame, the position where the chip and the metal heat sink are welded, and the position where the metal heat sink is located in the shell. Therefore, the radio frequency device of the present application has a very high sealing performance, and also effectively prevents oxidation of the metal pins of the chip, the leads, the metal pins of the lead frame, the position where the chip and the metal heat sink are welded, and the position where the metal heat sink is located in the shell. In the background technology, the metal in the cavity needs to be electroplated with precious metals (such as gold or silver) to prevent oxidation.

[0053] Third aspect: quick assembly. The lead frame 2 and the metal heat sink 1 are bonded and fixed, and the cover plate 6 and the top of the lead frame 2 are bonded and fixed, so that the assembly of the housing is quick and convenient during the assembly process.

[0054] Fourth aspect: good thermoelectric performance. Since the potting glue operation is easy and does not need to play a supporting role, sealing materials with higher thermal conductivity and lower dielectric loss can be used to improve the thermoelectric performance of the device.

[0055] The chip is welded and fixed on the front side of the metal heat sink, the leads are connected to the metal pins of the chip and the metal pins of the lead frame, and the potting glue is poured to form a sealant. Each process is relatively simple.

[0056] In summary, the structure of the RF device of the present application is simple and universal, which makes the jig for producing the RF device of the present application universal, making the manufacture of the RF device of the present application quick, convenient and low-cost, and the thermoelectric performance is also better. The double-layer sealed structural feature of the RF device of the present application also makes the RF device of the present application extremely airtight, and thus has a high resistance to oxidation and corrosion, thereby making the RF device more reliable.

[0057] In the background technology, there are two technical ideas for radio frequency devices. Figure 1 It is a radio frequency device with a corresponding structure formed by OMP packaging technology. Figure 2 It is a radio frequency device with a corresponding structure formed by cavity packaging technology.

[0058] The radio frequency device of this application adopts its own unique technical ideas:

[0059] A three-section structured shell + potting glue is poured between the metal heat sink and the lead frame and covers the chip, the lead wires and the metal pins of the lead frame to form a sealant as the first layer of sealing + a first adhesive 81 and a second adhesive 82 to form the first layer of sealing.

[0060] In implementation, such as Figure 3 As shown, the outer surface of the shell is electroplated with tin.

[0061] The double-layer seal has provided a good seal for the RF device of the present application, so that the outer surface of the RF device of the present application has considerable anti-oxidation ability. Therefore, when electroplating the outer surface of the RF device of the present application, less expensive precious metal materials (such as gold, silver, etc.) can be used, and electroplating tin can be used.

[0062] In implementation, such as Figure 3 As shown, the metal heat sink 1 is a flat metal heat sink 1;

[0063] The cover plate 6 is a flat plate.

[0064] The metal heat sink adopts the simplest structure - flat plate structure, which is easy to manufacture. Even if the metal heat sink has different sizes, it can be prepared using the same jig.

[0065] The cover adopts the simplest structure - flat plate structure, which is easy to manufacture. Even if the cover varies in size, it can be prepared using the same jig.

[0066] In implementation, such as Figure 3 As shown, the metal heat sink 1 is a metal heat sink made of copper material;

[0067] The chip 3 is a chip that dissipates heat longitudinally and on the back side. The back side of the chip is fixed to the front side of a metal heat sink made of copper material by welding with sintered copper 7.

[0068] The back side of the chip 3, the sintered copper, and the metal heat sink made of copper material form a heat dissipation channel.

[0069] The chip dissipates heat longitudinally on the back side. The back side of the chip is fixed to the front side of the copper metal heat sink by sintered copper welding. In this way, the heat generated by the chip is quickly dissipated through the heat dissipation channel of the back side of the chip → sintered copper → copper metal heat sink. The sintered copper and copper metal heat sinks are made of the same material, have high welding stability, strong heat conduction ability, and can quickly conduct heat and dissipate heat.

[0070] In implementation, the inner side of the lead frame has a step 21, and the metal pin of the lead frame is arranged on the step surface of the step 21;

[0071] The lead wire is made of copper material, and the metal pins of the lead frame are made of copper material.

[0072] A step 21 is provided on the inner side of the lead frame to facilitate the connection of the metal pins of the chip and the metal pins of the lead frame during the manufacturing process, thereby speeding up the process.

[0073] In implementation, the thickness of the sintered copper ranges from greater than or equal to 40 micrometers to less than or equal to 140 micrometers.

[0074] The thickness of the sintered copper is determined by the fixed height of the chip.

[0075] About Metal Heat Sink:

[0076] As an optional method, the material of the metal heat sink can be one or more mutually embedded metal materials selected from copper with different oxygen contents, copper-molybdenum-copper with different proportions, diamond-copper, diamond-aluminum, and copper-based carbon composite materials.

[0077] In particular, the material surface of the metal heat sink can be electroplated with a thin layer of gold, silver, or partially electroplated with precious metals such as gold, silver, etc.

[0078] As a preferred embodiment, the surface of the metal heat sink is not electroplated with metal material.

[0079] Regarding the lead frame, the lead frame is a plastic lead frame or a ceramic lead frame. In particular, the metal pin of the lead frame is made of copper. The copper model can be oxygen-free copper of models such as C1020, C10100, C1011, and TU0.

[0080] Regarding chips, the chips include LDMOS chips, GaN chips, IGBT chips, ceramic capacitor chips, and the like.

[0081] About the glue used for bonding:

[0082] The first adhesive for bonding and fixing the lead frame 2 and the metal heat sink 1 is formed by a first adhesive glue. The first adhesive glue is:

[0083] One or more of epoxy glue, acrylic glue, polyurethane glue, silver-based solder or copper-based solder.

[0084] The second adhesive for bonding and fixing the cover plate 6 and the lead frame 2 is formed by a second adhesive. The second adhesive is:

[0085] One or more of nano silver glue, nano copper glue, gold tin solder, solder paste, and conductive glue is a metal solder with excellent electrical and thermal conductivity.

[0086] About the glue that forms the sealant:

[0087] The potting glue is a mixture of one or more of organic silica gel, silicone gel, silicone rubber and epoxy glue.

[0088] About the cover:

[0089] The cover plate is a metal cover plate, a plastic cover plate or a ceramic cover plate.

[0090] The chip 3 is soldered to the front side of the metal heat sink 1 by soldering. The solder is a wire such as gold wire, silver wire, aluminum wire, copper wire, aluminum-clad copper wire, palladium copper wire, aluminum-magnesium wire, etc.

[0091] The electroplated tin is pure tin, tin-lead alloy or lead-free tin.

[0092] A method for preparing a radio frequency device of the present application comprises the following steps:

[0093] Adhere the lead frame 2 to the front side of the metal heat sink 1;

[0094] The chip 3 is welded and fixed on the front side of the metal heat sink 1, and the chip 3 is located in the space surrounded by the lead frame 2;

[0095] Connecting the metal pins of the chip and the metal pins of the lead frame with wires to form leads 4;

[0096] The potting glue is poured between the metal heat sink 1 and the lead frame 2 and covers the metal pins and leads of the chip, the metal pins of the lead frame, the welding position of the chip and the metal heat sink, and the position of the metal heat sink in the housing to form the sealant 5;

[0097] The cover plate 6 is bonded and fixed on the top of the lead frame 2;

[0098] The outer surface of the housing is electroplated with tin, and the housing includes a metal heat sink 1 , a lead frame 2 and a cover plate 6 .

[0099] The packaging process of the radio frequency device of the present application includes the following steps in chronological order:

[0100] Assembly of semi-finished products;

[0101] Chip welding;

[0102] Wire bonding;

[0103] Covered with potting glue;

[0104] Cover seal;

[0105] Surface is tin plated.

[0106] The steps of semi-finished product assembly specifically include:

[0107] Distribute the first bonding glue between the metal heat sink 1 and the lead frame 2 by dispensing or printing;

[0108] Then, according to the type of the first bonding glue, the semi-finished metal heat sink 1 and the lead frame 2 are assembled by heating at 100° C. to 1000° C. for 0.5 h to 4 h.

[0109] The steps of chip welding include:

[0110] Apply solder to the metal heat sink 1 by a dispensing machine or a printer, with the dispensing thickness being 30 to 150 microns;

[0111] Then the chip is bonded to the solder coating position using a bonding pressure of 5 to 200 mg by a bonding machine;

[0112] Finally, the product is placed in an oven and heated and cured at an air pressure of 0 to 10 MPa and a baking temperature of 150 to 300°C for 1 to 10 hours.

[0113] The wire bonding step may be ultrasonic wedge bonding or hot pressure ball bonding to connect the metal pins of the chip 3 and the metal pins of the lead frame 2 with the wires.

[0114] The specific steps of potting glue covering include:

[0115] Inject potting glue into the inner cavity of the lower part of the shell formed by the metal heat sink 1 and the lead frame 2 by dispensing or spraying. The height of the potting glue needs to be less than the height of the inner cavity and greater than the solder dispensing thickness in chip welding.

[0116] The product is then placed in an oven and heated and cured for 0.5 to 10 hours using an air pressure of -5 MPa to 5 MPa and a baking temperature of 80 to 250°C.

[0117] The specific steps of cover sealing include:

[0118] The second adhesive is applied to the cover plate by dispensing or printing, and then pressed onto the semi-finished product that has been filled with glue. The product is sealed by heating and curing at a pressure of 0Mpa to 10Mpa and a baking temperature of 80 to 250°C for 0.5 to 5 hours.

[0119] The specific steps of surface tinning include:

[0120] First, the sealed product is pickled, and then placed in stannous sulfate at a temperature of 10 to 50°C and a concentration of 10 to 80 g / L, and electroplated with tin at a current density of 1 to 10 A / m2 to complete the entire packaging process.

[0121] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0122] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0123] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0124] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0125] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0126] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A radio frequency device, characterized in that: include: A shell of a three-section structure, wherein the shell comprises, from bottom to top, a metal heat sink (1), a lead frame (2) and a cover plate (6); the lead frame (2) is bonded and fixed to the front side of the metal heat sink (1), and the cover plate (6) is bonded and fixed to the top of the lead frame (2); A chip (3) disposed in the housing and fixed by welding to the front surface of the metal heat sink (1); A lead (4) is arranged in the housing, the lead (4) connecting a metal pin of the chip and a metal pin of the lead frame; A sealant (5) is formed in the housing, wherein the sealant (5) is formed by pouring the sealant between the metal heat sink and the lead frame and covering the metal pins and leads of the chip, the metal pins of the lead frame, the welding position of the chip and the metal heat sink, and the position of the metal heat sink in the housing; The sealing of the chip and the lead wire is a double-layer sealing, wherein the first layer of sealing is achieved by a first adhesive (81) for bonding and fixing the lead frame (2) and the metal heat sink (1), and a second adhesive (82) for bonding and fixing the cover plate (6) and the top of the lead frame (2); and the second layer of sealing is achieved by the sealant.

2. The radio frequency device according to claim 1, characterized in that: The outer surface of the shell is electroplated with tin.

3. The radio frequency device according to claim 2, characterized in that: The metal heat sink is a flat plate type metal heat sink; The cover plate is a flat plate.

4. The radio frequency device according to any one of claims 1 to 3, characterized in that: The metal heat sink is a metal heat sink made of copper; The chip is a chip that dissipates heat longitudinally and on the back side, and the back side of the chip is fixed to the front side of a metal heat sink made of copper material by welding with sintered copper (7); The back side of the chip, the sintered copper, and the metal heat sink made of copper material form a heat dissipation channel.

5. The radio frequency device according to claim 4, characterized in that: The inner side of the lead frame has a step, and the metal pin of the lead frame is arranged on the step surface of the step; The lead wire is made of copper material, and the metal pins of the lead frame are made of copper material.

6. The radio frequency device according to claim 4, characterized in that: The thickness of the sintered copper ranges from greater than or equal to 40 micrometers to less than or equal to 140 micrometers.

7. A method for preparing a radio frequency device according to any one of claims 1 to 6, characterized in that: The steps include: Adhere and fix the lead frame (2) to the front side of the metal heat sink (1); The chip (3) is welded and fixed on the front side of the metal heat sink (1), and the chip (3) is located in the space surrounded by the lead frame (2); Connecting the metal pins of the chip and the metal pins of the lead frame with wires to form leads; The sealing glue is poured between the metal heat sink and the lead frame and covers the metal pins and leads of the chip, the metal pins of the lead frame, the welding position of the chip and the metal heat sink, and the position of the metal heat sink in the housing to form the sealing glue (5); The cover plate (6) is bonded and fixed on the top of the lead frame (2).

8. The method for preparing a radio frequency device according to claim 7, characterized in that: The following steps are also included: The outer surface of the shell is electroplated with tin, and the shell comprises a metal heat sink (1), a lead frame (2) and a cover plate (6).

9. The method for preparing a radio frequency device according to claim 7, characterized in that: The step of pouring the potting glue between the metal heat sink and the lead frame and covering the metal pins and leads of the chip, the metal pins of the lead frame, the welding position of the chip and the metal heat sink, and the position of the metal heat sink in the housing to form the sealant (5) specifically comprises: Injecting potting glue into the inner cavity of the lower part of the shell formed by the metal heat sink (1) and the lead frame (2) by dispensing or spraying, and the height of the potting glue needs to be less than the height of the inner cavity and greater than the thickness of the solder dispensing in chip welding; The product is then placed in an oven and heated and cured for 0.5 to 10 hours using an air pressure of -5 MPa to 5 MPa and a baking temperature of 80 to 250°C.

10. The method for preparing a radio frequency device according to claim 7, characterized in that: The step of bonding and fixing the lead frame (2) to the front surface of the metal heat sink (1) specifically comprises: Distributing the first bonding glue between the metal heat sink (1) and the lead frame (2) by dispensing or printing; Then, depending on the type of the first bonding glue, the metal heat sink (1) and the lead frame (2) semi-finished product are assembled by heating at 100° C. to 1000° C. for 0.5 h to 4 h.

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