Surface mount radio frequency metal package

Abstract

The application discloses a surface-mounted radio frequency metal package, which is compact in structure, high in airtightness level and excellent in heat dissipation. The application is implemented by the following technical scheme: three-core low-frequency beads pass through the elliptical holes symmetrically arranged along the long side center line of the semiconductor chip at both ends, and single-core radio frequency beads pass through the circular assembling holes symmetrically arranged along the wide side center line of the semiconductor chip at both ends, and then are welded on the box-shaped metal shell; the bottom of the metal shell is provided with a rectangular metal platform and a metal column which is arranged around the single-core radio frequency bead; the lower edges of the rectangular metal platform, the inner conductor of the single-core radio frequency bead and the inner conductor of the three-core low-frequency bead are located on the same horizontal plane; the semiconductor chip is connected with a radio frequency printed board; radio frequency interconnection with the outside world is realized through the radio frequency beads; the power supply and control ports of the semiconductor chip are bonded to the low-frequency beads through the peripheral filter devices to realize low-frequency interconnection with the outside world; and the metal cover plate is welded on the box-shaped metal shell through laser sealing welding to realize high airtightness level sealing.

Description

Technical Field

[0001] This invention relates to a surface mount device (SMD) in the field of semiconductor packaging, and more specifically, to a metal package with high hermeticity, excellent heat dissipation, operation in the radio frequency band, compact structure, and adaptability to modern surface mount processes. Technical Background

[0002] Semiconductor chips require packaging before use. Packaging has four main functions: protecting the chip from damage caused by the environment and transmission; providing interconnection for the chip's signal input and output; providing physical support for the chip; and heat dissipation. Generally, semiconductor chips undergo three levels of packaging before becoming final electronic products. The first level of packaging involves encapsulating the discrete semiconductor chip into independent functional modules; the second level of packaging involves mounting these functional modules onto a motherboard to achieve overall functionality; and the third level of packaging involves mounting this motherboard into the final product. This invention pertains to the first level of packaging.

[0003] Currently, first-level packaging is mainly classified by material into plastic packaging, ceramic packaging, and metal packaging. Plastic packaging has low cost but suffers from low hermeticity, poor heat dissipation, and poor RF performance. Ceramic packaging offers high hermeticity and good RF performance, but also suffers from poor heat dissipation. Both of these packaging types, relying on electrical interconnect technologies such as Ball Grid Array (BGA) and Leadless Chip Carrier (LCC), can become surface mount components, adapting to modern surface mount processes and enabling automated and efficient assembly in second-level packaging. With the development of electronic technology, surface mount components have been increasingly widely used, especially in high-frequency circuit design, where they have become indispensable circuit components. Surface mount integrated packaged RF devices are leadless, using their bottom pads for mounting and soldering onto printed circuit boards. Surface mount components mainly include rectangular chip components, cylindrical chip components, composite chip components, and irregularly shaped chip components. With the miniaturization of electronic products, a significant portion of consumer products are surface mount devices (SMDs) mounted on FPCs (Flexible Printed Circuits) to complete the assembly of the entire device due to space constraints. Surface mount technology (SMT) on FPCs has become one of the development trends in SMT technology.

[0004] Compared to the two packaging methods mentioned above, metal packaging offers advantages such as high hermeticity, good RF performance, and excellent heat dissipation. However, traditional metal packaging is bulky and heavy, requiring fixation and reliance on connectors and cables for electrical interconnection. Furthermore, it is largely impossible to utilize modern assembly processes in the secondary packaging stage. Therefore, in low- and medium-power applications, where integration and automated assembly requirements are increasingly stringent, it is gradually being phased out. In high-power applications, its irreplaceable heat dissipation capabilities significantly limit the integration and automation levels of electronic products. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing a metal package that is compact, has a high airtightness, excellent heat dissipation, operates in the radio frequency band, and is compatible with modern surface mount technology.

[0006] The above-mentioned objectives and advantages of the present invention can be achieved through the following scheme. A surface mount radio frequency (RF) metal package includes: a chip metal carrier plate 2 soldered to the bottom end of a box-shaped metal housing 5 and disposed in the middle of the long side of the housing; a surface-mount semiconductor chip 3 soldered to the chip metal carrier plate 2; a single-core RF glass bead 7 symmetrically arranged along the center line of the wide side of the semiconductor chip 3; and two three-core low-frequency glass beads 6 symmetrically arranged along the center line of the long side of the semiconductor chip 3. The three-core low-frequency glass beads 6 are soldered together to the box-shaped metal housing 5 through elliptical holes symmetrically arranged at both ends along the center line of the long side of the semiconductor chip 3, and the single-core RF glass beads 7 are soldered together through circular mounting holes symmetrically arranged at both ends along the center line of the wide side of the semiconductor chip 3. Two RF printed circuit boards 4 are soldered to the bottom plate of the box-shaped metal housing 5. The bottom is provided with a rectangular metal platform 8 and a metal pillar 9 that surrounds the single-core RF glass bead 7. The lower edges of the rectangular metal platform 8, the metal pillar 9, the inner conductor of the single-core RF glass bead, and the inner conductor of the three-core low-frequency glass bead are located on the same horizontal plane and are interconnected with the single-core RF glass bead 7 by spot welding. The RF port of the semiconductor chip 3 is connected to the RF printed circuit board 4 by gold wire bonding 10 and is interconnected with the outside world by the RF glass bead 7. The power supply and control ports of the semiconductor chip 3 are connected to the low-frequency glass bead 6 by gold wire bonding 10 and its surrounding filter devices to achieve low-frequency interconnection with the outside world. The metal cover plate 1 is laser-sealed onto the box-shaped metal shell 5 to achieve a high airtightness level seal.

[0007] Compared with the prior art, the present invention has the following advantages:

[0008] High airtightness and excellent heat dissipation. This invention first welds a chip metal carrier plate 2 to the bottom of a box-shaped metal housing 5, placing it in the middle of the long side of the housing. Then, a semiconductor chip 3 and its surrounding filters (such as capacitors and inductors) are welded to the upper surface of the chip metal carrier plate 3. Two single-core RF glass beads 7 symmetrically arranged along the center line of the wide side of the semiconductor chip 3, and two three-core low-frequency glass beads 6 symmetrically arranged along the center line of the long side of the semiconductor chip 3 [Du Ming 1] are welded to the box-shaped metal housing 5. A metal cover plate 1 is laser-sealed onto the metal housing 5, achieving a high airtightness level. By first welding the semiconductor chip and its surrounding filter components to the chip metal carrier plate 2 and then welding them together to the metal housing 5, and utilizing a highly thermally conductive metal as a heat sink path, excellent heat dissipation is achieved.

[0009] This invention features excellent RF performance and a compact structure. It employs a three-core low-frequency glass bead 6 connected to a single-core RF glass bead 7 via symmetrical elliptical holes along the long side centerline of a semiconductor chip 3, and two symmetrical circular mounting holes along the wide side centerline of the semiconductor chip 3. Both are soldered onto a box-shaped metal housing 5. Two RF printed circuit boards 4 are soldered to the base plate of the box-shaped metal housing 5 and interconnected with the single-core RF glass bead 7 via spot welding. The RF ports of the semiconductor chip 3 are connected to the RF printed circuit boards 4 via gold wire bonding 10 and interconnected with external devices via the RF glass bead 7. The power supply and control ports of the semiconductor chip 3 are bonded to the low-frequency glass bead 6 via gold wire bonding 10 and surrounding filter devices, achieving low-frequency interconnection with external devices. It can operate in the RF band and exhibits excellent RF characteristics. The interconnection with external devices utilizes highly integrated glass beads instead of low-integration connectors and cables, resulting in a compact structure.

[0010] This invention is compatible with modern surface mount technology (SMT) processes. The bottom of the metal housing 5 of this invention is provided with a rectangular metal platform 8 and metal pillars 9 surrounding a single-core RF glass bead 7. The lower edges of the rectangular metal platform 8, metal pillars 9, the inner conductor of the single-chip RF glass bead, and the inner conductor of the three-core low-frequency glass bead are located on the same horizontal plane. Therefore, this invention can be surface mounted onto the mother printed circuit board of the second-level package using a surface mount technology (SMT) process to achieve interconnection with other functional modules. This surface mount method is similar to the fusion of BGA and LCC soldering methods, which not only facilitates automation, improves production efficiency, reduces costs, and saves materials, energy, equipment, manpower, and time, but also reduces electromagnetic and radio frequency interference, resulting in high reliability, strong vibration resistance, and a low solder joint defect rate. Since both BGA and LCC are compatible with modern surface mount technology, this invention is also compatible with modern surface mount technology. Attached Figure Description

[0011] Figure 1 This is an exploded view of the surface-mount metal package of the present invention;

[0012] Figure 2 yes Figure 1 An open-top 3D schematic diagram;

[0013] Figure 3 yes Figure 2 A bottom view.

[0014] In the diagram: 1. Metal cover plate; 2. Chip metal carrier plate; 3. Semiconductor chip; 4. RF printed circuit board; 5. Box-shaped metal housing; 6. Three-core low-frequency glass bead; 7. Single-core RF glass bead; 8. Rectangular metal stage; 9. Metal pillar; 10. Gold wire. Detailed Implementation

[0015] See Figures 1-3 In the preferred embodiment described below, a surface-mount radio frequency metal package includes: a chip metal carrier plate 2 soldered to the bottom of a box-shaped metal housing 5 and disposed in the middle of the long side of the housing; a surface-mount semiconductor chip 3 soldered to the chip metal carrier plate 2; two single-core radio frequency glass beads 7 symmetrically arranged along the center line of the wide side of the semiconductor chip 3; and two three-core low-frequency glass beads 6 symmetrically arranged along the center line of the long side of the semiconductor chip 3. The three-core low-frequency glass bead 6 is welded together with the single-core radio frequency glass bead 7 through symmetrical elliptical holes along the long side centerline of the semiconductor chip 3 and symmetrical circular mounting holes along the wide side centerline of the semiconductor chip 3. Two radio frequency printed circuit boards 4 are welded to the bottom plate of the box-shaped metal housing 5. The bottom of the metal housing 5 is provided with a rectangular metal platform 8 and a metal pillar 9 surrounding the single-core radio frequency glass bead 7. The lower edges of the rectangular metal platform 8, the metal pillar 9, the inner conductor of the single-chip radio frequency glass bead, and the inner conductor of the three-core low-frequency glass bead are located on the same horizontal plane and are interconnected with the single-core radio frequency glass bead 7 by spot welding. The radio frequency port of the semiconductor chip 3 is connected to the radio frequency printed circuit board 4 through gold wire bonding 10 and is interconnected with the outside world through the radio frequency glass bead 7. The power supply and control ports of the semiconductor chip 3 are connected to the low-frequency glass bead 6 through gold wire bonding 10 and its surrounding filter devices to achieve low-frequency interconnection with the outside world. The metal cover plate 1 is laser-sealed onto the box-shaped metal housing 5 to achieve a high airtightness level. Semiconductor chip 3 is soldered onto the upper surface of chip metal carrier plate 2, and the geometric centers of the two coincide.

[0016] See Figure 3 The bottom four corners and center of the box-shaped metal housing 5 are provided with metal platforms 8, which are rectangular platforms that reinforce and support the semiconductor chip 3 around the center, and the metal platforms 8 are similar to the soldering method of leadless chip carrier LCC package.

[0017] A metal pillar 9 surrounds the inner conductor of the RF glass bead 7. The metal pillar 9 around the circumference of the RF glass bead 7 provides electromagnetic shielding for RF signals. The soldering method of the inner conductor of the RF glass bead 7 and the metal pillar 9 is similar to that of a ball grid array (BGA) package. The I / O terminals of the BGA package are distributed in an array of circular or columnar solder points on the bottom of the package, thereby improving the assembly yield and improving its electrothermal performance. To ensure compatibility with surface mount technology, the inner conductor of each glass bead, the metal platform 8 of the metal housing 5, and the lower edge of the metal pillar 9 are on the same plane.

[0018] In optional embodiments, the metal cover plate 1 and the metal housing 5 can be aluminum alloy or copper, or other high thermal conductivity metals capable of laser sealing. The radio frequency printed circuit board 4 can be a hybrid printed circuit board or a high- and low-temperature co-fired ceramic circuit board. The low-frequency glass beads 6 and the radio frequency glass beads 7 can be selected in specific positions, quantities, and core counts according to actual conditions. The chip metal carrier plate 2 can be selected from high thermal conductivity metals that match the thermal expansion coefficient of the specific material of the metal housing 5.

[0019] It should be understood that any parts not described in detail in this specification belong to the prior art. The above description of the preferred embodiments is quite detailed, but it should not be considered as a limitation on the scope of protection of this invention. Those skilled in the art, under the guidance of this invention, can make substitutions or modifications without departing from the scope of protection of the claims of this invention, and all such substitutions or modifications fall within the scope of protection of this invention. The scope of protection of this invention should be determined by the appended claims.

Claims

1. A surface-mount radio frequency metal package, comprising: A chip metal carrier plate (2) is welded to the bottom of a box-shaped metal housing (5) and set in the middle of the long side of the housing. A surface semiconductor chip (3) is welded to the chip metal carrier plate (2). Two single-core radio frequency glass beads (7) are symmetrical along the center line of the wide side of the semiconductor chip (3). Two three-core low-frequency glass beads (6) are symmetrical along the center line of the long side of the semiconductor chip (3). The three-core low-frequency glass beads (6) are welded to the box-shaped metal housing (5) together through elliptical holes symmetrical at both ends along the center line of the long side of the semiconductor chip (3). The single-core radio frequency glass beads (7) are welded to the box-shaped metal housing (5) together through circular mounting holes symmetrical at both ends along the center line of the wide side of the semiconductor chip (3). Two radio frequency printed circuit boards (4) are welded to the bottom plate of the box-shaped metal housing (5). A rectangular... The metal platform (8) and the metal pillar (9) surrounding the single-core RF glass bead (7) are arranged on the same horizontal plane. The lower edges of the rectangular metal platform (8), the metal pillar (9), the inner conductor of the single-chip RF glass bead and the inner conductor of the three-core low-frequency glass bead are located on the same horizontal plane. They are connected to the single-core RF glass bead (7) by spot welding. The RF port of the semiconductor chip (3) is connected to the RF printed circuit board (4) by gold wire bonding (10) and is connected to the outside world by the RF glass bead (7). The power supply and control port of the semiconductor chip (3) is bonded to the low-frequency glass bead (6) by gold wire bonding (10) and its surrounding filter devices to achieve low-frequency interconnection with the outside world. The metal cover plate (1) is welded to the box-shaped metal shell (5) by laser sealing to achieve a high airtightness level seal. To ensure compatibility with surface mount technology, the inner conductor of each glass bead, the metal platform (8) of the metal shell (5), and the lower edge of the metal pillar (9) are on the same plane.

2. The surface mount radio frequency metal package as described in claim 1, characterized in that: The semiconductor chip (3) is soldered onto the upper surface of the chip metal carrier plate (2), and the geometric centers of the two coincide.

3. The surface mount radio frequency metal package as described in claim 1, characterized in that: The bottom four corners and center of the box-shaped metal housing (5) are provided with metal platforms (8) that reinforce and support the strength of the rectangular platform of the semiconductor chip (3) around the center.

4. The surface mount radio frequency metal package as described in claim 1, characterized in that: A metal pillar (9) is provided around the inner conductor of the radio frequency glass bead (7), and the metal pillar (9) around the circumference of the radio frequency glass bead (7) serves as electromagnetic shielding for radio frequency signals.

5. The surface mount radio frequency metal package as described in claim 4, characterized in that: BGA packaged I / O terminals are arranged in an array of circular or columnar solder points on the underside of the package to improve electrothermal performance.

Images