A surface mount package port and hermetic package for a V-band device

Abstract

The application provides a kind of V wave band device's surface mount package port and air-tight package, it includes substrate (1), it is characterized in that: two layers of ground metal layer (5) are provided on substrate (1), a group of chips (2) are provided on one of ground metal layer (5), a group of metal filling columns (6) are provided in substrate (1), coplanar waveguide (7) is communicated on one side of each chip (2) and constitutes V wave band port, two chips (2) are communicated by second coplanar waveguide (8), and upper cover is further connected on substrate (1).The application has the advantages of simple structure, convenient to use, mass production, high reliability, strong adaptability and the like.

Description

Technical fields: This invention relates to the field of electronic communication equipment packaging technology, and in particular to a surface-mount package port and hermetic packaging for a V-band device. Background technology: With the rapid development of dual-use military and civilian communication equipment, miniaturization, lightweighting, high bandwidth, and high reliability are the future development trends of electronic communication equipment. New communication equipment places higher demands on device packaging. Currently, communication systems are being used more and more widely, and the demand for communication capacity is increasing dramatically. Under the requirement of high bandwidth, system operating frequencies are also increasing, hence the widespread use of millimeter-wave transmitter chips. Since bare chips generally cannot be directly tested and used, traditional methods often employ metal packaging, bare chip plastic encapsulation, and ceramic shell hermetically sealed packaging.

[0001] The V-band is a spectrum segment of the millimeter wave band from 40 GHz to 75 GHz. Within this band, the wavelength is relatively short and the directionality is good, which provides both security and directionality for communication. At the same time, this band has the characteristics of large bandwidth, high resolution, and strong anti-interference and anti-interception capabilities. Therefore, the use of V-band millimeter wave devices has become one of the main frequency bands for the development of future secure communication systems.

[0002] However, packaging V-band millimeter-wave devices has always been a challenge for devices in this band. Currently, LTCC (low-temperature co-fired ceramic) is commonly used for packaging in frequency bands below 30GHz. This packaging method has good compatibility, high integration, and is easy to use, but it has greater losses at higher frequency bands.

[0003] Currently, most foreign countries use standard waveguides for this frequency band. While this method can reduce the size of the device to some extent, it greatly limits the further miniaturization of the device and makes it difficult to integrate the device further. At present, China has proposed a waveguide microstrip conversion packaging structure. Although it improves the integration of the device and reduces the size of the device to a certain extent, the external interface must be in the form of a waveguide, which is inconvenient for installation and use and makes it difficult to integrate the device with other back-end circuits. Summary of the Invention: The present invention aims to overcome the shortcomings of the prior art by providing a packaging port and hermetically sealed packaging for V-band devices. This application provides the following technical solution: A surface-mount package port and hermetic packaging for a V-band device, comprising a substrate, characterized in that: an upper and lower ground metal layer are respectively provided on the upper and lower surfaces of the substrate, a set of chips are provided on the upper ground metal layer, a set of vias are provided on the substrate, and metal filler pillars communicating with the upper and lower ground metal layers are filled in the vias. Each chip has a coplanar waveguide unit connected to one side. A second coplanar waveguide connected to the chip is provided on the upper ground metal layer between the two chips. A set of surface-mount ports connected to the chip is provided on the lower ground metal layer below each chip. The chip is connected to the coplanar waveguide by bonding wire. The chip includes a voltage-controlled oscillator (VCO), a frequency quadrupler chip, and an amplifier chip. The frequency quadrupler and VCO are integrated together. The VCO generates a Ku-band radio frequency signal with a center frequency of 15 GHz. The generated signal is divided into two paths, which are used as the local oscillator and radio frequency output signals, respectively. The radio frequency output path is converted by the frequency quadrupler to form a V-band radio frequency signal with a center frequency of 60 GHz for signal output. Each port is connected to a surface-mount transmission line via bonding leads. A top cover is provided on the upper grounding metal layer to cover the entire upper grounding metal layer.

[0004] Based on the above technical solutions, the following further technical solutions are also possible: The upper cover includes a frame connected to the grounded metal layer on the substrate at its lower end, and a cover plate connected to the frame.

[0005] The coplanar waveguide unit includes an upper coplanar waveguide distributed on an upper ground metal layer, a lower coplanar waveguide distributed on a lower ground metal layer, and a metal filling pillar distributed between and communicating with the two.

[0006] Advantages of the invention: This invention has the advantages of simple structure, ease of use, mass production capability, high reliability, and strong adaptability. It also enables further miniaturization of millimeter-wave devices, facilitating integration with backend circuits. Attached image description: Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 yes Figure 1 Top view after removing the top cover; Figure 3 This is a schematic diagram of the coplanar waveguide structure of the present invention; Figure 4 This is a target verification diagram of a transmission port formed by a coplanar waveguide unit; Figure 5 This is a schematic diagram of another transmission port formed by another coplanar waveguide unit. Detailed implementation method: like Figure 1 and 2As shown, a surface-mount package port and hermetic package of a V-band device includes a substrate 1 made of ALN, Al2O3 or Rogers material, with corresponding upper ground metal layer 5 and lower ground metal layer 5a covering the upper and lower surfaces of the substrate 1.

[0007] A set of vias connecting the upper and lower surfaces of the substrate 1 is provided on the substrate 1. Metal filler pillars 6 are filled in the vias, and the upper ground metal layer 5 and the lower ground metal layer 5a are connected through the metal filler pillars 6. In this way, a spatial loop is formed between the radio frequency signal and the ground, which reduces the influence of the radio frequency signal on other signals in the board. In addition, it also serves to shield other signals and prevent them from interfering with it.

[0008] Two spaced-apart chips 2 are arranged on the upper ground metal layer 5. Each chip contains a voltage-controlled oscillator (VCO), a frequency multiplier (QM), and an amplifier chip, with the QM integrated on a single chip. The VCO generates a Ku-band radio frequency (RF) signal with a center frequency of 15 GHz. The generated signal is split into two paths, serving as the local oscillator and RF output signals, respectively. The RF output path undergoes frequency conversion via the QM to form a V-band RF signal with a center frequency of 60 GHz, which is then output.

[0009] Each chip 2 has a coplanar waveguide unit on one side, forming two transmission ports. Chip 2 is connected to the coplanar waveguide unit by bonding wire. One of the coplanar waveguide units forms a Ku-band port with a center frequency of about 15 GHz, and the other coplanar waveguide unit forms a V-band port with a center frequency of about 60 GHz.

[0010] The coplanar waveguide unit includes an upper coplanar waveguide a fabricated on the upper grounded metal layer 5 through an isolation groove c with a closed-loop structure. In the isolation groove c with the closed-loop structure, there are two parallel longitudinal straight line segments c2. One end of the straight line segment is connected to an arc-shaped groove c3, and the other end is connected to a horizontal line segment c4.

[0011] An in-layer coplanar waveguide b is fabricated on the lower ground metal layer 5a through a U-shaped second isolation trench c1. The upper and lower coplanar waveguides a and b are connected by metal filler pillars 6 distributed between them and communicating with them. The coplanar waveguide unit is connected to the corresponding chip 2 through bonding leads d. The width of the second isolation trench c1 is greater than the width of the isolation trench c. The diameter of the metal filler pillars 6 inside the coplanar waveguide unit is greater than the diameter of other metal filler pillars 6 outside the coplanar waveguide unit. The isolation trench c and the second isolation trench c1 in the two coplanar waveguide units have the same structure, the only difference being the size of the isolation trench c and the second isolation trench. Figure 2 The meaning can be presented without any doubt, so I won't go into details here. The arrangement of coplanar waveguide units, through the upper and lower coplanar waveguides a and b forming a conductor-back-to-back coplanar waveguide, can greatly reduce the characteristic impedance of the coplanar waveguide by forming two parallel capacitors between the middle transmission line and the metal ground on both sides, as well as between the middle transmission line and the lower end metal.

[0012] A second coplanar waveguide 7 is fabricated on the upper grounding metal layer 5 between the two chips 2 through another pair of isolation slots c, which is used to connect the two chips 2. The chips 2 and the second coplanar waveguide 7 are connected by bonding wires.

[0013] During signal transmission, the radio frequency signals generated by the chip are simultaneously output through coplanar waveguides and transmitted to the bottom of the substrate via vertical transmission lines. Finally, the radio frequency signals generated by the device are transmitted through the surface-mount transmission lines of the ground metal layer 5a at the bottom of the substrate.

[0014] A set of surface-mount ports connected to chip 2 is provided on the lower ground metal layer 5a below each chip 2.

[0015] A top cover is provided on the upper grounding metal layer 5, covering the entire upper grounding metal layer 5. The top cover includes a metal frame 3 whose lower end is connected to the grounding metal layer 5 on the substrate 1, and a metal cover plate 4 is connected to the frame 3. Encapsulation is completed by sealing and shielding electromagnetic waves.

[0016] Theoretical analysis and calculations were performed on this coplanar waveguide (CPW) structure, and the approximate zero-order impedance formula for the coplanar waveguide is as follows: The relative permittivity =1+ -1) In the formula The ratio of a first-type complete elliptic integral, (0≤k≤0.707) (0.707≤k≤1) in, = k5= The value of a is Figure 3 The width of 2a is half of the width of b. Figure 3 The width of 2b is half of the substrate width, h is the substrate thickness, and t is the thickness of the ground metal layer. Based on the above theoretical analysis and calculations, the signal transmission interfaces at both ends are designed.

[0017] Since the signal needs to be transmitted from the upper coplanar waveguide to the lower coplanar waveguide of this structure, the transmission metal via in the middle of the dielectric substrate needs to be designed. The via design is achieved through analysis, and the via inductance can be expressed by the following formula: [h·In( )+ (r-)] (pH) h is Figure 1 The value of r represents the thickness of substrate 1. Figure 1 The radius of the metal-filled column 6 in the middle, ρ represents magnetic permeability, measured in micrometers.

[0018] The resistance of a via can be approximated using the following expression: = Where, =, It is the operating frequency. It is the permeability. t is the electrical conductivity of the metal, and t is the thickness of the dielectric substrate. It is its DC resistance.

[0019] like Figure 4 and Figure 5 As shown, based on the above theoretical analysis, two high-frequency surface-mount transmission ports x were designed, and the two ports were simulated and verified using electromagnetic simulation software, meeting the relevant requirements.

Claims

1. A surface-mount package port and hermetic packaging for a V-band device, comprising a substrate (1), characterized in that: An upper ground metal layer (5) and a lower ground metal layer (5a) are respectively provided on the upper and lower surfaces of the substrate (1). A set of chips (2) are provided on the upper ground metal layer (5). A set of vias are provided on the substrate (1). Metal filling pillars (6) that communicate with the upper ground metal layer (5) and the lower ground metal layer (5a) are filled in the vias. A coplanar waveguide unit is connected to one side of each chip (2). A second coplanar waveguide (7) connected to the chip (2) is provided on the upper ground metal layer (5) between the two chips (2). A set of surface-mount ports connected to the chip (2) is provided on the lower ground metal layer (5a) below each chip (2). An upper cover covering the entire upper grounding metal layer (5) is provided on the upper grounding metal layer (5); The upper cover includes a frame (3) connected at its lower end to the upper ground metal layer (5) on the substrate (1), and a cover plate (4) connected on the frame (3). The coplanar waveguide unit includes an upper coplanar waveguide (a) distributed on the upper ground metal layer (5) and a lower coplanar waveguide (b) distributed on the lower ground metal layer (5a), as well as a metal filling pillar (6) distributed between and communicating with the two.

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