Radio frequency mother board with antenna and transceiving channel integrated

Abstract

The invention relates to the technical field of radio frequency circuits, aims to solve the problems that an existing radio frequency mother board is insufficient in heat dissipation and limited by the number of pressing times, and the signal interconnection and isolation design difficulty of all functional layers is large, and provides a radio frequency mother board integrating an antenna and a receiving and transmitting channel. Comprising a control signal layer, a power supply layer, a metal heat dissipation layer, a radio frequency network layer and an antenna layer which are stacked in sequence, and all the functional layers are pressed to form a printed board; a T / R module is arranged above the printed board; the metal heat dissipation layer adopts a metal plate provided with a metal boss, and one end of the metal boss sequentially penetrates through the power supply layer and the control signal layer and is connected with the T / R module grounding area; the lower surface of the power supply layer, the upper surface of the radio frequency network layer and the metal heat dissipation layer are connected through copper paste sintering holes; grounding via holes are formed in the control signal layer and the power supply layer, one end of each grounding via hole is connected with the metal heat dissipation layer, the other end of each grounding via hole is connected with the grounding copper foil on the upper surface of the printed board, and the metal structural member is in contact with the grounding copper foil on the upper surface of the printed board.

Description

Technical Field

[0001] This invention relates to the field of radio frequency circuit technology, and more specifically, to a radio frequency motherboard that integrates an antenna and a transceiver channel. Background Technology

[0002] Compared to traditional phased arrays, planar phased arrays offer significant advantages in terms of size, weight, and cost, and have broad application prospects in fields such as satellite communication and UAV detection. The integrated architecture of the antenna and RF transceiver channel is an important technical path to achieve the planarization and lightweighting of phased array systems. Its core is to integrate the antenna radiating layer, control and power layer, and RF network layer onto a multi-layer PCB (printed circuit board), and assemble it with active components such as the T / R (transmit / receive) module and amplitude / phase control module using surface mount technology to form the RF motherboard, achieving compact integration of the antenna array and RF front-end.

[0003] In this integrated architecture, the RF motherboard integrates multiple functions and is the key to the entire system design. It usually faces the following two difficulties, which are particularly prominent in millimeter-wave phased array systems with small antenna element spacing.

[0004] First, under this architecture, one surface of the PCB is an array antenna, making it impossible to install metal heat dissipation structures. The heat dissipation path can only be on the device mounting surface of the PCB, resulting in limited heat dissipation space, high difficulty in heat dissipation design, and limiting the output power of the T / R module. Second, due to the limitation of the number of PCB manufacturing laminations (usually no more than 3 laminations), the signals of each layer in the RF motherboard cannot be interconnected in any way. The functional layers need to be connected to each other while also being isolated to avoid signal crosstalk, making the PCB layer design difficult. Summary of the Invention

[0005] The present invention aims to provide an integrated RF motherboard that combines the antenna and transceiver channels, in order to solve the problems of insufficient heat dissipation, limited number of bonding cycles, and high difficulty in the design of signal interconnection and isolation between functional layers in existing RF motherboards.

[0006] This invention is achieved using the following technical solution: The present invention provides an integrated radio frequency motherboard for antenna and transceiver channels, comprising a control signal layer, a power layer, a metal heat dissipation layer, a radio frequency network layer and an antenna layer arranged in sequence, and all the above functional layers are laminated to form a printed circuit board. A T / R module is arranged on top of the printed circuit board; The metal heat dissipation layer is made of a metal plate with metal bosses. One end of the metal bosses passes through the power layer and the control signal layer in sequence and is connected to the grounding area of ​​the T / R module. The lower surface of the power layer, the upper surface of the RF network layer, and the metal heat dissipation layer are all connected by copper paste sintering holes. Grounding vias are provided on the control signal layer and the power layer. One end of the grounding via is connected to the metal heat dissipation layer, and the other end of the grounding via is connected to the grounding copper foil on the upper surface of the printed circuit board. The metal structural component is in contact with the grounding copper foil on the upper surface of the printed circuit board. Heat dissipation is achieved through the metal heat dissipation layer, the grounding via, and the metal structural component.

[0007] The upper surface of the printed circuit board refers to the upper surface of the control signal layer.

[0008] This invention achieves heat dissipation through the metal heat dissipation layer embedded in the composite substrate, connecting the metal bosses of the metal heat dissipation layer to the grounding area of ​​the T / R module, connecting the power layer, RF network layer and metal heat dissipation layer through copper paste sintering holes, connecting one end of the grounding via to the metal heat dissipation layer, connecting the other end of the grounding via to the grounding copper foil on the upper surface of the printed circuit board, and making the metal structural component contact the grounding copper foil on the upper surface of the printed circuit board. This solves the problem of insufficient heat dissipation in existing RF motherboards. Through innovative stacking design, it solves the problem of signal interconnection and isolation between functional layers under the condition of limited number of composite substrate lamination cycles.

[0009] As a preferred technical solution: The control signal layer and the power layer are pressed together once to form a pressed assembly, while the radio frequency network layer and the antenna layer are each pressed together separately. After the first pressing, the first pressing component, the RF network layer and the metal heat dissipation layer are pressed a second time to form the second pressing component. The control signal layer is located above the power layer, and the metal heat dissipation layer is located between the power layer and the RF network layer. The secondary-pressed assembly is then pressed a third time with the antenna layer after the first pressing.

[0010] By adopting the above pressing method, the number of pressing times is limited to no more than 3. At the same time, the signals between each functional layer are connected and isolated to avoid signal crosstalk.

[0011] As a preferred technical solution: The lower surface of the power layer, the upper surface of the radio frequency network layer, and the metal heat dissipation layer are connected by a first copper paste sintering hole and a second copper paste sintering hole, respectively; the lower surface of the radio frequency network layer and the upper surface of the antenna layer are connected by a third copper paste sintering hole.

[0012] As a preferred technical solution: The grounding via is connected to the metal heat dissipation layer through the first copper paste sintering hole.

[0013] As a preferred technical solution: The metal structure is positioned above the control signal layer, and a portion of the metal structure is located directly above the ground via, in contact with the ground copper foil on the upper surface of the control signal layer.

[0014] As a preferred technical solution: Other parts of the metal structure may also come into contact with grounded copper foil at other locations on the upper surface of the control signal layer.

[0015] As a preferred technical solution: The radio frequency signal of the T / R module is connected to the conductor of the radio frequency network layer through the first via. The first via penetrates the control signal layer, the power layer and the metal heat dissipation layer, and the lower end of the first via extends into the radio frequency network layer, while the upper end of the first via is connected to the space where the T / R module is located.

[0016] Signal connectivity is achieved through the above methods.

[0017] As a preferred technical solution: The radio frequency signal of the T / R module is connected to the feed point of the antenna layer through the second via. The second via passes through the control signal layer, power layer, metal heat dissipation layer and radio frequency network layer, and the lower end of the second via extends into the antenna layer, while the upper end of the second via is connected to the space where the T / R module is located.

[0018] Signal connectivity is achieved through the above methods.

[0019] As a preferred technical solution: The upper surface of the T / R module is in contact with the metal structural components through an elastic thermal pad.

[0020] As a preferred technical solution: A first grounding hole is provided on the antenna layer, and a second grounding hole is provided on the radio frequency network layer.

[0021] As a preferred technical solution: The metal boss is flush with the upper surface of the printed circuit board and is connected to the ground BGA ball of the T / R module.

[0022] As a preferred technical solution: The metal plate has multiple metal protrusions arranged in a dot matrix pattern, and the metal protrusions are integrally formed with the metal plate.

[0023] As a preferred technical solution: The metal plate is made of copper, the same material as the copper foil used for grounding the printed circuit board.

[0024] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. This invention solves the problem of insufficient heat dissipation of existing RF motherboards by embedding a metal heat dissipation layer in the composite substrate and combining it with copper paste sintering process. Through innovative stacking design, it solves the problem of signal interconnection and isolation of each functional layer under the condition of limited number of composite substrate lamination times. 2. This invention integrates the antenna array, radio frequency network, control and power supply on a single PCB board, eliminating interconnection structures such as connectors and cables, which greatly reduces the thickness of the phased array, thereby reducing volume, weight and cost. 3. This invention achieves good heat dissipation and heat dissipation effects by embedding a metal heat dissipation layer, effectively improving the heat dissipation capacity of the RF motherboard; 4. In this invention, the control signal layer, power layer, radio frequency network layer, and antenna layer are distributed on both sides of the metal heat dissipation layer to ensure good isolation between high and low frequency signals. 5. This invention uses copper paste sintered holes to improve wiring density and design flexibility. Each functional layer can be designed with independent wiring and grounding holes. The grounding holes do not need to consider whether they interfere with other functional layers. Good grounding continuity can be achieved between different functional layers through copper paste sintered holes, while also enhancing heat dissipation. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the radio frequency motherboard that integrates the antenna and the transceiver channel according to the present invention.

[0026] Figure 2 This is a schematic diagram of the structure of the metal heat dissipation layer described in this invention.

[0027] Figure 3 This is a schematic diagram of the heat dissipation of the radio frequency motherboard that integrates the antenna and transceiver channel according to the present invention.

[0028] Icons: 1-Control signal layer, 2-Power layer, 3-Metal heat dissipation layer, 31-Metal boss, 32-Metal plate, 4-RF network layer, 5-Antenna layer, 61-First copper paste sintering hole, 62-Second copper paste sintering hole, 63-Third copper paste sintering hole, 71-First via, 72-Grounding via, 73-First grounding hole, 74-Second grounding hole, 75-Second via, 8-T / R module, 9-Elastic thermal pad, 10-Metal structural component. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1 like Figure 1 As shown, this embodiment proposes an integrated RF motherboard for antenna and transceiver channels, comprising a control signal layer 1, a power layer 2, a metal heat dissipation layer 3, an RF network layer 4, and an antenna layer 5 stacked sequentially from top to bottom. All these functional layers are formed into a single printed circuit board through multiple laminations. Preferably, each functional layer is formed by laminating several layers of core boards. To balance performance and cost, the control signal layer 1 and power layer 2 can be made of low-frequency materials, while the RF network layer 4 and antenna layer 5 can be made of high-frequency materials.

[0031] The control signal layer 1 and the power layer 2 are pressed together once to form a pressed assembly, and the radio frequency network layer 4 and the antenna layer 5 are each pressed together separately.

[0032] After the first pressing, the first pressing assembly, the radio frequency network layer 4 and the metal heat dissipation layer 3 are pressed together again to form a second pressing assembly. The control signal layer 1 is located above the power layer 2, and the metal heat dissipation layer 3 is located between the power layer 2 and the radio frequency network layer 4.

[0033] Preferably, the lower surface of the power layer 2, the upper surface of the radio frequency network layer 4, and the metal heat dissipation layer 3 are all connected through copper paste sintering holes. Specifically, the lower surface of the power layer 2, the upper surface of the radio frequency network layer 4, and the metal heat dissipation layer 3 are connected through the first copper paste sintering hole 61 and the second copper paste sintering hole 62, respectively. In this way, the power layer 2 and the radio frequency network layer 4 are grounded by using the copper paste sintering process.

[0034] like Figure 2 As shown, the metal heat dissipation layer 3 is a metal plate 32 with metal bosses 31. Preferably, the metal plate 32 has multiple metal bosses 31 arranged in a dot matrix. The metal bosses 31 and the metal plate 32 are integrally formed by CNC milling to ensure relative positional accuracy. There are 64 metal bosses 31 arranged on the metal plate 32. The first copper paste sintering hole 61 is arranged between the power layer 2 and the metal plate 32, and the second copper paste sintering hole 62 is arranged between the radio frequency network layer 4 and the metal plate 32.

[0035] One end of the metal boss 31 is fixedly connected to the metal plate 32. The other end of the metal boss 31 passes through the power layer 2 and the control signal layer 1 in sequence. The upper surface of the metal boss 31 is flush with the upper surface of the printed circuit board, that is, flush with the upper surface of the control signal layer 1. Furthermore, the metal boss 31 is connected to the grounding copper foil of the surrounding printed circuit board through an electroplating process.

[0036] Metal plate 32 is made of copper, which is the same material as the copper foil for grounding the printed circuit board. It has the best thermal expansion coefficient matching. The thickness is generally between 0.5mm and 2mm. The thickness is selected according to the weight requirements and heat dissipation requirements of the RF motherboard. The thicker the copper plate, the better the heat dissipation effect.

[0037] The RF motherboard also includes a T / R module 8, which is positioned above the control signal layer 1. A metal boss 31 is located on the lower part of the T / R module 8 (the grounding area directly below the T / R module 8), and the metal boss 31 is connected to the ground BGA ball of the T / R module 8. Preferably, the cross-sectional dimension of the metal boss 31 is smaller than the cross-sectional dimension of the T / R module 8.

[0038] The upper surface of the T / R module 8 is in contact with the metal structure 10 via an elastic thermal pad 9. Preferably, the elastic thermal pad 9 may be, but is not limited to, a thermally conductive silicone sheet.

[0039] Preferably, the radio frequency signal of the T / R module 8 is connected to the conductor of the radio frequency network layer 4 through the first via 71. The first via 71 penetrates the control signal layer 1, the power layer 2, and the metal heat dissipation layer 3, and the lower end of the first via 71 extends into the radio frequency network layer 4, while the upper end of the first via 71 is connected to the space where the T / R module 8 is located. The first via 71 can be achieved by back-drilling.

[0040] The secondary-pressed assembly after the second pressing is pressed a third time with the antenna layer 5 after the first pressing.

[0041] Preferably, the radio frequency signal of the T / R module 8 is connected to the feed point of the antenna layer 5 through the second via 75. The second via 75 penetrates the control signal layer 1, the power layer 2, the metal heat dissipation layer 3, and the radio frequency network layer 4, with the lower end of the second via 75 extending into the antenna layer 5 and the upper end of the second via 75 communicating with the space where the T / R module 8 is located. The second via 75 can be implemented by back-drilling.

[0042] Preferably, a first grounding hole 73 is provided on the antenna layer 5, and a second grounding hole 74 is provided on the radio frequency network layer 4. The first grounding hole 73 is vertically disposed through the antenna layer 5, and the second grounding hole 74 is vertically disposed through the radio frequency network layer 4. The first grounding hole 73 and the second grounding hole 74 can be densely disposed to ensure good internal grounding and isolation effects without considering interference and avoidance with other functional layers.

[0043] Preferably, the lower surface of the RF network layer 4 and the upper surface of the antenna layer 5 are connected through copper paste sintering holes. Specifically, the lower surface of the RF network layer 4 and the upper surface of the antenna layer 5 are connected through a third copper paste sintering hole 63. In this way, the RF network layer 4 and the antenna layer 5 are grounded by using the copper paste sintering process.

[0044] Preferably, the copper paste sintering holes can be set in a dense manner to ensure grounding continuity between different functional layers.

[0045] Grounding vias 72 are provided on the control signal layer 1 and the power layer 2. The lower end of the grounding via 72 is connected to the first copper paste sintering hole 61, and the upper end of the grounding via 72 is connected to the grounding copper foil on the upper surface of the printed circuit board (the surface layer of the RF motherboard, i.e., the upper surface of the control signal layer 1 is covered with grounding copper foil). The grounding copper foil is connected to the metal heat dissipation layer 3 through the grounding via 72 and the first copper paste sintering hole 61. The grounding copper foil is not covered with solder mask. The metal structural component 10 is arranged above the RF motherboard, and a part of the metal structural component 10 is located directly above the grounding via 72 and in contact with the grounding copper foil on the upper surface of the control signal layer 1.

[0046] Other parts of the metal structure 10 may also contact the grounded copper foil at other locations on the upper surface of the control signal layer 1.

[0047] The RF motherboard is interlocked with the metal structure 10 by screws. The RF motherboard and the metal structure 10 contact each other for heat dissipation, that is, the metal structure 10 contacts the grounded copper foil on the upper surface of the control signal layer 1 for heat dissipation.

[0048] Using the above structure, heat is conducted to the metal plate 32 through the metal boss 31, and then transferred to the grounding copper foil on the surface of the RF motherboard through the first copper paste sintering hole 61 and the grounding via 72. The grounding copper foil is in close contact with the metal structural component 10, ultimately achieving good heat dissipation and heat equalization. The surface of the T / R module 8 contacts the metal structural component 10 through an elastic thermal pad 9, which can achieve auxiliary heat dissipation. The heat dissipation path is as follows: Figure 3 As indicated by the dashed arrow.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A radio frequency motherboard integrating an antenna and a transceiver channel, characterized in that: It includes a control signal layer, a power layer, a metal heat dissipation layer, an RF network layer, and an antenna layer arranged in sequence. All of these functional layers are laminated together to form a printed circuit board. A T / R module is arranged on top of the printed circuit board; The metal heat dissipation layer is made of a metal plate with metal bosses. One end of the metal bosses passes through the power layer and the control signal layer in sequence and is connected to the grounding area of ​​the T / R module. The lower surface of the power layer, the upper surface of the RF network layer, and the metal heat dissipation layer are all connected by copper paste sintering holes. Grounding vias are provided on the control signal layer and the power layer. One end of the grounding via is connected to the metal heat dissipation layer, and the other end of the grounding via is connected to the grounding copper foil on the upper surface of the printed circuit board. The metal structural component is in contact with the grounding copper foil on the upper surface of the printed circuit board. Heat dissipation is achieved through the metal heat dissipation layer, the grounding via, and the metal structural component.

2. The RF motherboard integrating the antenna and transceiver channel according to claim 1, characterized in that: The control signal layer and the power layer are pressed together once to form a pressed assembly, while the radio frequency network layer and the antenna layer are each pressed together separately. After the first pressing, the first pressing component, the RF network layer and the metal heat dissipation layer are pressed a second time to form the second pressing component. The control signal layer is located above the power layer, and the metal heat dissipation layer is located between the power layer and the RF network layer. The secondary-pressed assembly is then pressed a third time with the antenna layer after the first pressing.

3. The RF motherboard integrating the antenna and transceiver channel according to claim 1, characterized in that: The lower surface of the power layer, the upper surface of the radio frequency network layer, and the metal heat dissipation layer are connected by a first copper paste sintering hole and a second copper paste sintering hole, respectively; the lower surface of the radio frequency network layer and the upper surface of the antenna layer are connected by a third copper paste sintering hole.

4. The RF motherboard integrating the antenna and transceiver channel according to claim 3, characterized in that: The grounding via is connected to the metal heat dissipation layer through the first copper paste sintering hole.

5. The RF motherboard integrating the antenna and transceiver channel according to claim 4, characterized in that: The metal structure is positioned above the control signal layer, and a portion of the metal structure is located directly above the ground via, in contact with the ground copper foil on the upper surface of the control signal layer.

6. The RF motherboard integrating the antenna and transceiver channel according to claim 1, characterized in that: The radio frequency signal of the T / R module is connected to the conductor of the radio frequency network layer through the first via. The first via penetrates the control signal layer, the power layer and the metal heat dissipation layer, and the lower end of the first via extends into the radio frequency network layer, while the upper end of the first via is connected to the space where the T / R module is located.

7. The RF motherboard integrating the antenna and transceiver channel according to claim 1, characterized in that: The radio frequency signal of the T / R module is connected to the feed point of the antenna layer through the second via. The second via passes through the control signal layer, power layer, metal heat dissipation layer and radio frequency network layer, and the lower end of the second via extends into the antenna layer, while the upper end of the second via is connected to the space where the T / R module is located.

8. The RF motherboard integrating the antenna and transceiver channel according to claim 1, characterized in that: The upper surface of the T / R module is in contact with the metal structural components through an elastic thermal pad.

9. The RF motherboard integrating the antenna and transceiver channel according to claim 1, characterized in that: A first grounding hole is provided on the antenna layer, and a second grounding hole is provided on the radio frequency network layer.

10. The RF motherboard integrating the antenna and transceiver channel according to claim 1, characterized in that: The metal boss is flush with the upper surface of the printed circuit board and is connected to the ground BGA ball of the T / R module.

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