A small DC motor drive circuit module metal packaging method and packaging structure

Abstract

A small DC motor drive circuit module metal packaging method and packaging structure belong to the microelectronic packaging technical field. It includes metal tube seat, heat sink pit, cap ring, tube cap, tube seat pin, insulator, copper plated ceramic substrate, chip, bonding wire and packaging filling insulation glue. The heat sink pit is made in the inner cavity area of the metal tube seat, the cap ring is set on the top periphery of the metal tube seat, the tube seat pin is set through the bottom of the metal tube seat, the copper plated ceramic substrate is used as the circuit integrated board, the copper plated ceramic substrate is installed in the heat sink pit, the chip is attached and bonded, the packaging filling insulation glue is filled and solidified, and the metal tube cap is sealed and welded with the metal tube seat. It has the characteristics of small volume, high integrated power density and high integration. It solves the problems of large packaging volume, heavy weight and poor thermal reliability of the existing small DC motor drive circuit module. It is widely used in the technical field of semiconductor devices, semiconductor power devices and hybrid integrated circuit packaging.

Description

Technical Field

[0001] This invention belongs to the field of microelectronic packaging technology, and more specifically to the field of power electronic devices. In particular, it relates to a metal packaging method and packaging structure for a small DC motor drive circuit module. Background Technology

[0002] In the field of integrated circuit electronic packaging, low-loss, high-power control modules have long relied on PCB-level packaging structures. This technology has developed into a mature product design system and process solution over many years, and is widely used in general electronic devices due to its advantages of low cost and convenient processing. However, with the rapid iteration of new-generation intelligent drive control systems, new energy vehicle drive systems, high-precision weapon control systems, and especially the stringent requirements for electronic devices in the aerospace, aviation, and shipborne defense and military fields, the inherent defects of traditional PCB-level packaging are becoming increasingly prominent, making it difficult to adapt to technological development trends.

[0003] Currently, drive control devices are evolving towards miniaturization, lightweight design, high heat dissipation efficiency, high power density, low power consumption, high temperature resistance, corrosion resistance, and radiation resistance. However, when discrete device functional modules are integrated and packaged at the PCB level, there are two major bottlenecks: First, during system-level assembly, the dispersed layout of discrete devices results in a large overall module size, high space occupancy, and heavy weight, directly leading to low system integration efficiency and failing to meet the compact design requirements of high-end equipment. Second, the heat dissipation path of PCB-level packaging is singular, and heat easily accumulates in densely packed areas of devices. In addition, the packaging structure lacks sufficient protection, making devices susceptible to external corrosive media, contaminant contamination, and electromagnetic interference. Ultimately, this makes it difficult to increase the power density of the product, limits application scenarios, and significantly reduces the reliability of operation in harsh environments such as high temperature, high humidity, and strong corrosion.

[0004] Traditionally packaged small DC motor drive integrated circuit modules generally suffer from large size and heavy weight, and it is difficult to incorporate heat dissipation design during the overall assembly stage. Poor heat dissipation during module operation not only significantly reduces electrical performance but also makes them prone to overheating failure under high-temperature environments, thus affecting the overall operational stability. To overcome the technical bottlenecks of traditional packaging and meet the trend of lightweight development, small DC motor drive functional integrated circuits urgently need to adopt system-in-package (SIP) solutions.

[0005] System-in-Package (SiP) is a crucial technological direction for breaking through existing limitations in integrated circuits, and the accompanying packaging and testing technologies have become key links in industrial upgrading. Metal-surface hermetic packaging components, with their high mechanical strength, excellent insulation performance, small size, light weight, good heat dissipation, corrosion resistance, and good sealing properties, can effectively meet the requirements of use under extreme conditions. They have significant advantages in high-end scenarios such as aerospace, automotive electronics, and intelligent driving, and their future application space is very broad.

[0006] Based on the aforementioned industry pain points, traditional packaging technologies can no longer meet the development needs of high-end equipment manufacturing and emerging industries. Developing a hybrid integrated driver circuit module ceramic packaging product that combines high integration, high reliability, excellent heat dissipation performance, and strong environmental adaptability has become an urgent need for industry development and a core direction for market competition.

[0007] To meet the needs of industry development and the market, there is an urgent need to develop a hybrid integrated drive module for small DC motor drives that includes intermittent forward and reverse control of the motor and a step-down function.

[0008] In view of this, the present invention is hereby proposed. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to solve the problems of large package size, heavy weight, difficult heat dissipation design, and poor thermal reliability of existing small DC motor drive circuit modules.

[0010] The objective of this invention is to develop a small DC motor drive functional module that meets the requirements of intermittent forward and reverse motor control and has a voltage reduction function. The main technical feature is to utilize the excellent high thermal conductivity and high mechanical strength of Kovar alloy material to design and manufacture metal parts that meet the requirements of a small DC motor drive functional module with intermittent forward and reverse motor control and a voltage reduction function. The parts include a tube socket, a tube cap and a copper-plated ceramic substrate, while meeting the requirements of chip-level integration and high reliability operation.

[0011] Therefore, the present invention provides a method for metal packaging of a small DC motor drive circuit module. The method includes the following steps: (1) A metal tube socket is used as the tube socket for the metal surface mount packaging structure.

[0012] (2) Create a heat sink pit in the inner cavity area of ​​the metal tube seat.

[0013] (3) A sealing ring is set around the top of the metal pipe seat, the shape and size of which match the metal pipe cap.

[0014] (4) A tube seat pin (i.e., external electrode lead) is provided at the bottom of the metal tube seat, and the tube seat pin is isolated from the metal tube seat by an insulator.

[0015] (5) A copper-plated ceramic substrate is used as a circuit integration board. According to the circuit structure, different chip bonding areas, corresponding chip lead (i.e. metal bonding wire) bonding areas, and circuit traces are designed on the copper-plated ceramic substrate.

[0016] (6) Install the copper-plated ceramic substrate in the heat sink recess.

[0017] (7) Based on the circuit structure, perform chip mounting and chip bonding.

[0018] (8) Encapsulation, filling, and curing of insulating adhesive.

[0019] (9) Seal the metal cap and the metal pipe seat with a sealing weld.

[0020] The packaging structure of the metal packaging method for a small DC motor drive circuit module is as follows: Figure 1-3 As shown. Includes: Metal tube sockets, heat sink recesses, sealing rings, tube caps, tube socket leads (also known as external lead terminals), insulators, copper-plated ceramic substrates, chips, bonding wires, and encapsulation filler insulating adhesive.

[0021] The metal tube seat is provided with a sealing ring around its perimeter; The shape and size of the sealing ring are matched with the metal tube cap.

[0022] The inner cavity of the metal tube seat is provided with a heat sink pit.

[0023] The bottom of the metal socket is provided with a socket pin that penetrates through the bottom of the socket, and the end face of the socket pin located in the packaging cavity is the bonding end face.

[0024] The pins of the tube socket are isolated from the metal tube socket by an insulator. A pin inner cavity end face bonding area is formed on the end face of the pin.

[0025] The copper-plated ceramic substrate has copper plating on both sides, and the front side of the copper-plated ceramic substrate is provided with different chip bonding areas, corresponding chip lead bonding areas, and circuit traces.

[0026] The copper-plated ceramic substrate is installed in a heat sink recess.

[0027] The chip is mounted on the corresponding chip bonding area on the front side of the copper-plated ceramic substrate according to the circuit structure.

[0028] The top electrode of the chip is bonded to the corresponding bonding region via bonding wires.

[0029] The bonding end face of the socket pin is bonded to the corresponding bonding area by bonding wire.

[0030] The encapsulation filling insulating adhesive fills the inner cavity of the encapsulation.

[0031] The metal cap and the sealing ring are connected by a sealed weld.

[0032] The technical effects of this invention are as follows: (1) Excellent moisture-proof performance: The metal base itself has high density. After being sealed with the metal cap, the circuit module has excellent waterproof and moisture-proof capabilities and can operate stably in high humidity environments.

[0033] (2) Strong electromagnetic interference resistance: The metal hermetic packaging can provide reliable electromagnetic shielding effect, so that the module can remain stable in the electromagnetic environment and is not easily affected by external electromagnetic interference.

[0034] (3) Excellent electrical performance: The copper-plated ceramic substrate has excellent insulation performance. Combined with the low resistivity of the metal tube socket pins, it can effectively reduce parasitic impedance and inductive reactance, and suppress electromagnetic interference and signal crosstalk while reducing power consumption.

[0035] (4) Good mechanical protection performance: The metal tube base itself has high strength and strong impact resistance. The metal hermetic encapsulation can effectively protect the internal chip and reduce the damage caused by external mechanical impact.

[0036] (5) High reliability and airtightness: The metal package has good airtightness and the overall package is an airtight structure, which can effectively prevent water vapor, dust and other pollutants from entering the chip and avoid chip damage under high voltage and high current conditions.

[0037] (6) Stable thermal matching characteristics: The copper-plated ceramic substrate has a low coefficient of thermal expansion and is similar to the thermal expansion characteristics of the chip material. During high-temperature cycling, it can reduce the difference in thermal stress, reduce the risk of chip cracking failure due to thermal mismatch, and improve the long-term reliability of the device.

[0038] (7) High-efficiency heat dissipation: The copper-plated ceramic substrate material has excellent thermal conductivity. Combined with the stepped recessed heat sink design in the packaging cavity, it can effectively improve the heat capacity and heat dissipation efficiency of the chip and significantly improve the overall heat dissipation effect of the device.

[0039] Therefore, this invention possesses advantages such as small size, lightweight, high integration, excellent electrical insulation, good chemical properties, excellent electrical properties and high reliability, good space adaptability, high power density, strong reliability under high voltage and high current conditions, and wide application range. It can replace traditional board-level discrete device packaging, solving key problems such as large size, low power density, and limited application range, significantly saving space, optimizing system circuit layout, greatly improving heat dissipation efficiency, and reducing losses. Furthermore, through layered three-dimensional welding, the cavity volume can be reduced, and the recessed heat sink design improves heat dissipation efficiency and increases power density.

[0040] It can be widely used in various products with stringent reliability requirements, such as semiconductor devices, semiconductor power devices, and hybrid integrated circuits. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the encapsulation shell structure.

[0042] Figure 2 This is a schematic diagram of the circuit package structure.

[0043] Figure 3 Schematic diagram of the assembly structure of copper-plated ceramic substrate.

[0044] In the diagram: 1. Metal socket, 2. Heat sink recess, 3. Sealing ring, 4. Socket cap, 5. Socket pin, 6. Insulator, 7. Copper-plated ceramic substrate, 8. Chip, 9. Bonding wire, 10. Encapsulation filling insulating glue, 11. Pin inner cavity end face, 12. Pin inner cavity end face bonding area, 13. Copper-plated ceramic substrate chip mounting area, 14. Copper-plated ceramic substrate bonding area, 15. Copper-plated ceramic substrate circuit trace. Detailed Implementation

[0045] like Figure 1-3 As shown, the specific implementation method and packaging structure of the small DC motor drive circuit module metal packaging are as follows: The metal tube seat is square in shape.

[0046] The metal tube seat is a Kovar alloy metal tube seat.

[0047] The sealing ring and the metal tube seat are manufactured as a single unit.

[0048] The material of the socket pin is Kovar alloy, and the surface of the socket pin is copper plating layer and gold plating layer from the inside to the outside.

[0049] The surface of the copper-plated ceramic substrate is gold-plated.

[0050] The insulator is a glass insulator.

[0051] The encapsulation filling insulating adhesive is silicone rubber.

[0052] The bonding wire is a silicon-aluminum wire or a gold wire.

[0053] Based on the integrated circuit principle of a small DC motor drive functional module, to achieve intermittent drive control of a small DC motor with a voltage reduction function, the small DC motor intermittent drive functional module is packaged as a whole. A large heat sink recess is designed inside the Kovar alloy component socket, a cap ring is designed on the top of the socket, and ten external lead terminals are designed on the bottom of the socket. The cap ring ensures a reliable and secure connection between the Kovar alloy component socket and the cap during energy storage sealing, forming a sealed cavity that encapsulates the integrated chip and meets the requirements for airtightness and mechanical strength. The ten external lead terminals lead out the integrated circuit module electrodes, and bonding areas are designed on these ten leads to achieve electrical connection between the internal integrated circuit module electrodes and the lead electrodes. The heat sink area supports the copper-plated ceramic substrate, and fifteen bonding areas and fourteen bonding areas are designed on the copper-plated ceramic substrate.

[0054] Using copper-plated ceramic substrates as the carrier for chips and integration offers significant advantages over organic materials in terms of mechanical properties, thermal stability, and environmental tolerance. Copper-plated ceramic substrates not only have a low coefficient of thermal expansion and excellent heat dissipation efficiency, but also maintain stability in high-temperature and corrosive environments. This makes them well-suited to the key requirements of integrated circuit packaging, such as miniaturization, high power density, efficient heat dissipation, and high hermeticity. Metal-surface hermetic packaging achieves high integration at the chip level, reliably bonding the chip to the copper-plated ceramic substrate using a sintering process, and using a metal structure to ensure internal and external circuit conduction. Finally, a cap is used for sealing to achieve overall airtightness. This type of packaging significantly improves the mechanical strength, moisture and corrosion resistance, and electromagnetic shielding effect of devices, maintaining stable electrical performance even under high-temperature conditions and effectively avoiding performance degradation caused by temperature changes.

[0055] I. Encapsulation Case Studies The external structure of the packaging shell is as follows Figure 1 As shown. It mainly includes a small DC motor intermittent drive control module, Kovar alloy metal parts socket and cap, and a copper-plated ceramic substrate. It measures 35.00 mm in length, 21.80 mm in width, and 10.40 mm in height.

[0056] (1) The Kovar alloy component socket has a large heat sink recess, a cap ring on top, and ten external lead terminals at the bottom. The heat sink recess serves as the welding area for the copper-plated ceramic substrate. The external leads bring out the integrated circuit module electrodes for user soldering. To meet the demands of high current, the external leads are copper-clad. A bonding area is also designed on the external leads to facilitate electrical connection between the internal electrodes of the small DC motor intermittent drive control module and the external leads. Glass insulators are sintered between the external leads and the socket to meet both airtightness and mechanical strength requirements. The innermost layer of the external leads is made of copper. To meet the bonding requirements of the socket and the demands of harsh environments, a nickel plating is applied to the second layer of the external leads, and finally, a gold plating is applied to the third layer of the socket. Each lead is 6mm long. The thickness range of each metal layer in its surface metallization layer is as follows: the thickness of the second layer material, nickel, is 1.3 to 8.9 μm, the thickness of the third layer material, gold, is 0.7 to 1 μm, and the purity is ≥99.9%.

[0057] (2) The innermost material of the Kovar alloy metal part tube seat is Kovar alloy (material is 4J42 / 4J29). At the same time, in order to meet the bonding requirements of the tube seat and the needs of use in harsh environments, the second layer of the tube seat is plated with metallic nickel material, and finally the third layer of the tube seat is plated with metallic gold material. The thickness of the second layer of metallic nickel material is 1.3um to 8.9um, the thickness of the third layer of metallic gold material is 0.7um to 1um, and the purity is ≥99.9%.

[0058] (3) The outer surface of the bottom of the tube socket is provided with lead-out electrodes 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; the bonding areas of the inner cavity end face of the lead-out terminals of the tube socket lead-out electrodes are A1, A2, A3, A4, A5, A6, A7, A8, A9, and A10; the recessed area in the middle of the tube socket is the area that carries the copper-plated ceramic substrate.

[0059] (4) The function of the tube seat cap ring is to reliably fasten the Kovar alloy part tube seat and the tube cap to form a sealed cavity during energy storage sealing welding, so as to wrap the integrated chip and meet the requirements of airtightness and instrument strength.

[0060] (5) Assemble the copper-plated ceramic substrate in the heat sink area of ​​the Kovar alloy component tube socket to improve the heat dissipation performance of the module. Based on the electrical connection principle of the small DC motor intermittent drive control module, design the bonding area and bonding area of ​​the small DC motor intermittent drive control module on the ceramic substrate, reasonably design the size of each bonding area, and optimize the layout of the bonding area and bonding area to support each power chip while making its structure compact.

[0061] (6) The bonding areas of the copper-plated ceramic substrate are C31, C32, C2, C3, C4, C5, C6, C7, C8, C91, C92, C10, C11, C12, and C13, of which bonding areas C7 and C8 are power chip carrying areas; the bonding areas of the copper-plated ceramic substrate are B1, B2, B3, B4, B5, B6, B7, B81, B82, B83, B9, B10, B11, and B12. Among them, six bonding areas (C4, C8, C91, C92, C10, C12) and eleven bonding areas (A4, A5, A7, A10, B2, B5, B7, B2, B10, B1, B11) constitute the forward rotation control circuit of the small DC motor. Six bonding areas (C6, C7, C31, C32, C11, C12) and thirteen bonding areas (A9, A5, A7, A10, B83, B81, B5, B4, B6, B2, B9, B1, B11) form the forward rotation control circuit of the small DC motor. The bonding areas form a small DC motor reverse control circuit. The C12 bonding area and the three bonding areas B1, B11, and A10 form a common circuit for the forward and reverse control of the small DC motor. The C2 bonding area and the three bonding areas A4, B3, and A3, and the C13 bonding area and the three bonding areas A9, B10, and A8 respectively form the forward and reverse drive output power control circuits for the small DC motor, and can also form the forward and reverse drive control signal output circuits for the small DC motor. The forward and reverse control circuits of the small DC motor designed on the copper-plated ceramic substrate are controlled by an external switching power supply circuit, which is interlocked in pairs, so that only one power supply is always connected to the module. The forward and reverse power supply control of the motor is achieved by the switching of the external switch.

[0062] (7) The main material of the copper-plated ceramic substrate is Al2O3 ceramic (alumina) with a content of more than 95%. Copper plating and gold plating processes are used. Metallization is carried out in the areas where the die is designed and the bonding area is designed. Copper is plated locally and then gold is plated. This satisfies the requirements of die bonding and bonding, as well as the high voltage insulation requirements between the die bonding area and the bonding area. The entire reverse side of the copper-plated ceramic substrate is plated with copper and then gold, which increases the heat fusion of the module and effectively improves the reliability of this type of packaging structure under high power density, high voltage and high current operating conditions. The thickness of the second layer of material plated with metallic copper on the alumina ceramic substrate is 100um, and the thickness of the third layer of material plated with gold is 0.7~1um, with a purity of ≥99.9%.

[0063] (8) The electrical connection relationship between the inner and outer surfaces of the small DC motor intermittent drive control module is as follows: A1, A2-B1, A3-B3, A4-B2, A5-B4, A7-B5, B81-B82-B83, A8-B10, A9-B83, A10-B11.

[0064] II. Encapsulation Method Examples: First, inside the base of the tube socket, the copper-plated ceramic substrate and the chip are positioned and installed through the heat sink recess area. The chip and the package shell are solidified and bonded using a reflow soldering process. Then, through precision bonding technology, the electrical interconnection between the motor forward and reverse intermittent control circuit and the external lead-out electrodes of the package shell is achieved. Finally, parallel seam welding, energy storage welding or laser welding is used to complete the welding of the tube cap and the package socket cavity to achieve hermetic packaging.

[0065] This invention employs lead-tin-silver solder and a multi-temperature gradient sintering process to firmly bond the chip to the inner cavity of the package structure, achieving excellent chip curing effect and heat dissipation performance. Furthermore, the hermetically sealed packaging structure effectively prevents the chip from being damaged by external physical forces and contaminated by moisture and pollutants, improving the driver module's moisture resistance, corrosion resistance, and high-temperature resistance, further expanding its application range in complex environments and in driving both inductive and non-inductive loads.

[0066] The specific steps are as follows: (1) Clean the metal-encapsulated structural components: First, the metal-encapsulated structural parts are wet-cleaned and then baked using vacuum or nitrogen: First, the metal-encapsulated structural parts are soaked in acetone for 10 minutes, then ultrasonically cleaned at low frequency for 3 minutes, then rinsed with regular water for 5 minutes, then rinsed with deionized water for 10 minutes, and finally dehydrated with alcohol. After completion, they are baked in a nitrogen oven at 60℃.

[0067] Before use, the metal-encapsulated structural parts should be cleaned with argon plasma. The specific plan is as follows: the argon plasma cleaning power is preferably set to 100W, the argon flow rate is ≤50SCCM, and the cleaning time is preferably set to 180s. Each cleaning should be used within 24 hours.

[0068] (2) Clean the mold with wet method and bake it with vacuum or nitrogen. The method is the same as (1). If alcohol is used for dehydration, vacuum baking cannot be used. (3) Prepare each step-down power chip, each drive control chip, peripheral auxiliary control chip and copper-plated ceramic substrate to be packaged, and select welding materials: high temperature solder pads. Before use, the solder pads need to be plasma cleaned, and the method is the same as (1). (4) Install the chip as required. First, install the solder pads in each die-occupying area. Then, place the chip on the solder pads in each die-attaching area according to the position requirements. Then, place the quartz pressure block on the chip. Finally, place the assembled mold in a vacuum sintering furnace for high-temperature sintering. (5) Place the module from step (4) into a vacuum sintering furnace. Under nitrogen conditions, heat it to the preset temperature T1 at a set heating rate V1 and hold it for t1 time. Then, evacuate the furnace and fill it with nitrogen again after t1 time. Heat it to the preset temperature T2 at a set heating rate V2 and hold it for T3 time. Then, evacuate the furnace again and heat it to the preset temperature T3 (maximum temperature) at a set heating rate V3 and hold it for T5 time. Then, start cooling down at a set cooling rate V4. When the temperature drops below the melting point, start filling it with nitrogen. Finally, cool it down with the furnace to complete the sintering of the device. (Heating rate relationship: V1 > V2 > V3 > V4).

[0069] (6) The sintered module is placed on a bonding machine and wire bonded to the upper-layer chips and the inner surface electrodes and patterns of the outer shell using interconnect materials to obtain a module with interconnected electrical properties. (7) Place the device with completed electrical interconnection in step (6) into the energy storage welding equipment, install the tube cap on the metal package structure component tube seat, and seal the tube seat cap ring (1) with the tube cap to complete the module packaging of the high power density hybrid integrated microcircuit module.

[0070] All chips in the circuit module are silicon-based chips, and the metallization layer on the back can be silver (Ag).

[0071] The bottom of the chip is connected to the copper-plated ceramic substrate using a bottom solder, and the solder used for chip sintering is lead-tin-silver solder sheet.

[0072] The chip mounting requirements are: install the bottom layer solder, install the bottom layer chip on the bottom layer solder, and place a weight block on the bottom layer chip.

[0073] The pipe cap and the pipe seat sealing ring are connected by an energy storage weld. The outer shell and the pipe cap are sealed together in an airtight manner. After sealing, the internal water vapor content is ≤5000ppm, and the leakage rate is ≤1×10⁻⁶. -1 Pa·cm 3 / s.

[0074] The small DC motor drive module with intermittent forward and reverse control and voltage reduction function is connected to the inner surface electrode by metal wires. The metal wire material is silicon-aluminum wire with a diameter ≥100μm and a quantity of 53 wires.

[0075] Finally, it should be noted that the above embodiments are merely examples for clear illustration. This invention includes, but is not limited to, the above embodiments, and it is neither necessary nor possible to exhaustively describe all possible implementations. Those skilled in the art can make other variations or modifications based on the above description. All implementation schemes that meet the requirements of this invention are within the protection scope of this invention.

Claims

1. A method for metal packaging of a small DC motor drive circuit module, characterized in that, Including the following methods: (1) A metal tube socket is used as the tube socket for the metal surface mount packaging structure; (2) Create a heat sink recess in the inner cavity area of ​​the metal tube seat; (3) A sealing ring is installed around the top of the metal pipe seat, the shape and size of which match the metal pipe cap; (4) A tube socket pin is provided at the bottom of the metal tube socket, and the tube socket pin is isolated from the metal tube socket by an insulator; (5) A copper-plated ceramic substrate is used as a circuit integration board. According to the circuit structure, different chip bonding areas, corresponding wire bonding areas, and circuit traces are designed on the copper-plated ceramic substrate. (6) Install the copper-plated ceramic substrate in the heat sink recess; (7) Based on the circuit structure, perform chip mounting and chip bonding; (8) Encapsulation, filling, and curing of insulating adhesive; (9) Seal the metal cap and the metal pipe seat with a sealing weld.

2. The packaging structure of the metal packaging method for a small DC motor drive circuit module as described in claim 1, characterized in that, include: Metal tube sockets, heat sink recesses, sealing rings, tube caps, tube socket leads, insulators, copper-plated ceramic substrates, chips, bonding wires, and encapsulation filling insulating adhesive; The metal tube seat is provided with a sealing ring around its perimeter; The shape and size of the sealing ring are matched with the metal tube cap; The inner cavity area of ​​the metal tube seat is provided with a heat sink recess. The bottom of the metal tube socket is provided with a tube socket pin that penetrates the bottom of the socket, and the end face of the tube socket pin located in the packaging cavity is the bonding end face; The tube socket pins are isolated from the metal tube socket by an insulator; The copper-plated ceramic substrate has copper plating on both sides, and the front side of the copper-plated ceramic substrate is provided with different chip bonding areas, corresponding chip lead bonding areas and circuit traces. The copper-plated ceramic substrate is installed in the heat sink recess; According to the circuit structure, the chip is mounted on the corresponding chip bonding area on the front side of the copper-plated ceramic substrate. The top electrode of the chip is bonded to the corresponding bonding region via bonding wires; The bonding end face of the socket pin is bonded to the corresponding bonding area by bonding wire; The encapsulation filling insulating adhesive is filled into the encapsulation cavity; The metal cap and the sealing ring are connected by a sealed weld.

3. The packaging structure of the metal packaging method for a small DC motor drive circuit module as described in claim 2, characterized in that: The metal tube seat is a Kovar alloy metal tube seat, which is square in shape, and the surface of the tube seat is coated with a nickel plating layer and a gold plating layer from the inside to the outside.

4. The packaging structure of the metal packaging method for a small DC motor drive circuit module as described in claim 3, characterized in that: The Kovar alloy is made of 4J42 / 4J29, with a nickel plating layer thickness of 1.3µm to 8.9µm, a gold plating layer thickness of 0.7µm to 1µm, and a purity of ≥99.9%.

5. The packaging structure of the metal packaging method for a small DC motor drive circuit module as described in claim 2, characterized in that: The sealing ring and the metal tube seat are manufactured as a single unit.

6. The packaging structure of the metal packaging method for a small DC motor drive circuit module as described in claim 2, characterized in that: The material of the socket pin is Kovar alloy, and the surface of the socket pin is, from the inside to the outside, a copper plating layer, a nickel plating layer, and a gold plating layer.

7. The packaging structure of the metal packaging method for a small DC motor drive circuit module as described in claim 6, characterized in that: The thickness of the nickel plating layer is 1.3um to 8.9um, the thickness of the gold plating layer is 0.7um to 1um, and the purity is ≥99.9%.

8. The packaging structure of the metal packaging method for a small DC motor drive circuit module as described in claim 2, characterized in that: The copper-plated ceramic substrate is an Al2O3 alumina ceramic substrate with a content of more than 95%. It is made by copper plating and gold plating processes. Copper plating layer and gold plating layer are sequentially formed on the bonding area and the bonding area. Copper plating layer and gold plating layer are sequentially formed on the reverse side of the copper-plated ceramic substrate.

9. The packaging structure of the metal packaging method for a small DC motor drive circuit module as described in claim 8, characterized in that: The copper plating layer has a thickness of 100 μm, the gold plating layer has a thickness of 0.7 μm to 1 μm, and the purity is ≥99.9%.

10. The packaging structure of the metal packaging method for a small DC motor drive circuit module as described in claim 2, characterized in that: The insulator is a glass insulator, and the encapsulating filling insulating adhesive is silicone rubber.

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