Microwave digital board compounding mode

Abstract

The invention relates to the technical field of microwave communication, and particularly discloses a composite structure of a ten-layer microwave board and a digital board, and the stacking relation of the microwave board and the digital board is a first digital multilayer board, a bare chip, a microwave multilayer board and a second digital multilayer board. An integrated TR circuit and a power division circuit are arranged in the microwave multilayer board; wherein the digital signal and the power supply layer medium are made of a common FR4 material; the microwave circuit dielectric layer adopts R04350, and the line width of the microwave circuit dielectric layer is matched with the impedance; the mode can be applied to combination of microwave circuits and digital circuits of all frequency bands of microwaves, the space utilization rate is greatly improved, one board can replace several previous boards, the structure is simpler, and integration and miniaturization of the microwave circuits are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of microwave communications, and in particular to a microwave digital board composite method. Background Art

[0002] At present, microwave circuits and digital signals coexist in technical fields such as phased array radar systems and transceiver systems. The RF circuit is the core of the radar transceiver system, especially some airborne radars and missile-borne radars, which have higher and higher requirements for the transceiver system, not only in terms of better performance, but also in terms of smaller size and lighter weight. The digital circuit is responsible for the control and calculation of the entire system and is the nerve center of the entire system. In the classic TR system, due to the high frequency, considering many factors such as impedance and transmission rate, the microwave circuit and the digital circuit are separated. The traditional method is to transmit high-frequency RF signals on microstrip lines and digital signals on PCB boards. The biggest disadvantage of this method is that it takes up a lot of volume and space, and the cost and production cycle are also large, which is not conducive to the development of microwave integration and miniaturization. At present, LTCC technology is used for compounding on the market, but its process is very complicated and the cost is high, and the current compounding method cannot directly stick the bare chip to the middle layer circuit;

[0003] Therefore, a more perfect composite method is urgently needed. Summary of the invention

[0004] In view of this, the present invention provides a microwave digital board composite method to solve the problem that the composite process using LTCC technology on the market is very complicated, the cost is high, and the bare chip cannot be directly glued to the middle layer circuit.

[0005] In the first aspect, the present invention provides a microwave digital board composite method, characterized in that it includes: a composite structure of ten layers of microwave board and digital board, the stacking relationship of the above microwave board and digital board is a first digital multilayer board, a bare chip, a microwave multilayer board and a second digital multilayer board; the microwave multilayer board is provided with an integrated TR circuit and a power division circuit; wherein the digital signal and power layer dielectrics use ordinary FR4 material; the microwave circuit dielectric layer uses R04350, and its line width is adapted to the impedance.

[0006] As a preferred technical solution of the embodiment of the present invention, the stacking relationship is specifically as follows:

[0007] The top layer and M2 layer use the same double-sided core material, the material is FR4, the copper foil thickness is 1oz, which is used for packaging device mounting and the power supply routing;

[0008] The M3 and M4 layers use the same double-sided core material, the material is RO4350, the thickness is 4mil, the copper foil thickness is 0.5oz, and it is used for the digital signal routing;

[0009] The M5 and M6 layers use the same double-sided core material, which is RO4350 with a thickness of 4 mil and a copper foil thickness of 0.5 oz, and is used for the microwave circuit, bare chip and digital circuit;

[0010] The M7 and M8 layers use the same double-sided core material, the material is FR4, the copper foil thickness is 0.5oz, and is used for the digital signal routing;

[0011] M9 and the bottom layer use the same double-sided core material, the material is FR4, the copper foil thickness is 0.5oz, and is used for the digital signal routing, bottom layer devices and routing.

[0012] As a preferred technical solution of the embodiment of the present invention, a microstrip line and a stripline are provided on the front side of the composite board of the ten-layer microwave board and the digital board;

[0013] The microstrip line in the M5 layer and the M6 ​​layer needs to be dug, from the M5 layer to the M6 ​​layer; the M5 layer carries a microwave circuit, and includes a power division circuit, a power amplifier circuit and a switch circuit;

[0014] The M6 ​​layer is GND, and the position of the corresponding joint on the M6 ​​layer is dug from the bottom layer to the M6 ​​layer; and a metallization process of a preset thickness is performed on the M6 ​​layer for placing the bare chip.

[0015] As a preferred technical solution of an embodiment of the present invention, it also includes a radio frequency connector; the microwave signal enters through the radio frequency connector, the microwave signal first enters the microstrip line with only M5 layer and M6 layer, and then the microwave signal passes through the internal M5 layer of the microwave multilayer board and travels in the entire ten-layer microwave board. Finally, the microwave signal passes through the microstrip line with only M5 and M6 layers again, and is finally transmitted out through the radio frequency connector.

[0016] As a preferred technical solution of the embodiment of the present invention, the excavated portion of the microstrip line is realized by digging a hole.

[0017] As a preferred technical solution of the embodiment of the present invention, it further includes:

[0018] The power division circuit in the microwave multilayer board is used to distribute the microwave signal to multiple output paths, and each output path can independently control the power and switch state;

[0019] The power amplifier circuit in the microwave multilayer board is used to amplify the power of the microwave signal;

[0020] The switch circuit in the microwave multilayer board is used for switching the path or connection of the microwave signal;

[0021] The digital signal routing in the digital multilayer board is used to transmit digital signals and control signals to achieve control and regulation of the microwave circuit.

[0022] As a preferred technical solution of the embodiment of the present invention, it further includes:

[0023] The parameters of the microstrip line and the strip line on the front side of the composite board are adapted to the radio frequency characteristics of the radio frequency connector;

[0024] The selection and attachment method of the die are adapted to the performance and stability of the microwave circuit.

[0025] As a preferred technical solution of the embodiment of the present invention, it further includes:

[0026] Vias and pads are also provided next to the bare chip, which are used to provide power and control signals for the bare chip.

[0027] In summary, the beneficial effects of the present invention are as follows:

[0028] In order to solve the above technical problems, the present invention provides a microwave digital board composite method, including: a composite structure of a ten-layer microwave board and a digital board, wherein the stacking relationship between the microwave board and the digital board is a first digital multilayer board, a bare chip, a microwave multilayer board, and a second digital multilayer board; the microwave multilayer board is provided with an integrated TR circuit and a power division circuit; wherein the digital signal and power layer dielectrics use ordinary FR4 material; the microwave circuit dielectric layer uses R04350, and its line width is adapted to the impedance; this method can be applied to the composite of microwave circuits and digital circuits in various microwave frequency bands, greatly improving the space utilization rate, and one board can replace several previous boards, and the structure is simpler, realizing the integration and miniaturization of microwave circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solution of the examples of the present invention, the drawings required for use in the examples of the present invention will be briefly introduced below. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work, and these are all within the protection scope of the present invention.

[0030] Figure 1 It is a composite PCB appearance diagram of a microwave digital board composite method;

[0031] Figure 2 It is a first structural illustration of a composite method of a microwave digital board;

[0032] Figure 3 It is a second structural illustration of a microwave digital board composite method;

[0033] Figure 4It is a third structural illustration of a composite mode of a microwave digital board;

[0034] Figure 5 It is a fourth structural illustration of a microwave digital board composite method. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention example clearer, the technical solution in the present invention example will be described clearly and completely in conjunction with the drawings in the present invention example. It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such a process, method, article or device. In the absence of further restrictions, the elements defined by the phrase "comprising..." do not exclude the presence of other identical elements in the process, method, article or device comprising the elements. If there is no conflict, the various features in the embodiments and examples of the present invention can be combined with each other, all within the scope of protection of the present invention.

[0036] Example 1

[0037] See also Figures 1 to 5 The present invention provides a microwave digital board composite method, characterized in that it includes: a composite structure of a ten-layer microwave board and a digital board, wherein the stacking relationship between the microwave board and the digital board is a first digital multilayer board, a bare chip, a microwave multilayer board and a second digital multilayer board; the microwave multilayer board is provided with an integrated TR circuit and a power division circuit; wherein the digital signal and power layer dielectrics use ordinary FR4 material; the microwave circuit dielectric layer uses R04350, and its line width is adapted to the impedance.

[0038] The distribution of power layers, signal layers, and microwave layers is usually achieved through layer stacking; Top layer / top layer: This is usually the power layer, which is used for power supply and power signal distribution. It is located at the top, a certain distance away from the other layers; Signal layer: The signal layer is located below the power layer and is mainly used to transmit digital signals and other signal lines; there can be one or more signal layers; Microwave layer: The microwave layer is located below the signal layer and is mainly used to protect microwave circuits and transmit high-frequency signals. It usually has a lower dielectric constant and attenuation to support high-frequency signal transmission; Bottom layer / bottom layer: This is the last layer, usually used for ground plane and bottom layer device connection. It can also be used for signal line routing, especially for connection with bottom layer devices;

[0039] During the stacking process, layers are connected through vias and pads to achieve electrical connectivity. Vias are metal structures that connect pads to another layer through holes in the stacked board, thereby ensuring that signals and power are transmitted between different layers;

[0040] The power layer and the signal layer are connected through vias and pads to provide power and control signals to the die. The microwave signal passes through the power layer and the signal layer through the microstrip line, and then enters the microwave layer for processing;

[0041] The stacking relationship is as follows:

[0042] The top layer and M2 layer use the same double-sided core material, the material is FR4, the copper foil thickness is 1oz, which is used for packaging device mounting and the power supply routing;

[0043] The M3 and M4 layers use the same double-sided core material, the material is RO4350, the thickness is 4mil, the copper foil thickness is 0.5oz, and it is used for the digital signal routing;

[0044] The M5 and M6 layers use the same double-sided core material, which is RO4350 with a thickness of 4 mil and a copper foil thickness of 0.5 oz, and is used for the microwave circuit, bare chip and digital circuit;

[0045] The M7 and M8 layers use the same double-sided core material, the material is FR4, the copper foil thickness is 0.5oz, and is used for the digital signal routing;

[0046] M9 and the bottom layer use the same double-sided core material, the material is FR4, the copper foil thickness is 0.5oz, and is used for the digital signal routing, bottom layer devices and routing.

[0047] A microstrip line and a strip line are provided on the front of the composite board of the ten-layer microwave board and the digital board; the microstrip line substrate material is R04350B, the thickness is 4 mil, the strip line impedance is 50 oz, and the simulated line width is 0.19 mm; the strip line substrate material is R04350B, the thickness is 8 mil, the strip line impedance is 50 oz, and the simulated line width is 0.09 mm.

[0048] The microstrip line in the M5 and M6 layers needs to be dug out; see Figure 3 and Figure 4 , dug from the M5 layer to the M6 ​​layer; the M5 layer has a microwave circuit and includes a power division circuit, a power amplifier circuit and a switch circuit. The M5 layer integrates a power division circuit: divides the RF signal into multiple paths and applies it to multiple channels, with a frequency range of up to 65GHz; a power amplifier circuit: amplifies the small signal in multiple stages, and then amplifies it through push and power amplifier; a switch circuit: controls the switching of multiple signals; the M6 ​​layer is GND, please refer to Figure 5 , the position of the corresponding joint on the M6 ​​layer is dug from the bottom layer to the M6 ​​layer; and a metallization treatment of a preset thickness is performed on the M6 ​​layer for placing the bare chip, and it is bonded on it with conductive glue to ensure good grounding; the metallization treatment is generally achieved by gold plating 2um; about Figures 2 to 5 Technical description: The shadow part of Mechanica3 is dug from the top layer to the M5 layer; the shadow part of Mechanica5 is dug from the top layer to the M6 ​​layer; the shadow part of Mechanica11 is dug from the bottom layer to the M6 ​​layer; the thickness of the entire composite board after stacking is 1.2mm. The total thickness of the PCB board processed by this design is 1.2mm, the board is 117mm long and 32mm wide, and the microwave circuit occupies a size of 78mm long and 32mm wide; only one PCB board can be used to integrate digital circuits and microwave circuits; this design has been applied to the channel and TR design of phased array radars, and the actual effect has only a small deviation from the theoretical calculation, which is within the controllable range.

[0049] The M6 ​​layer is only dug at the position corresponding to the connector on the back of the composite board for connector installation. The bottom layer is immersion gold and sintered directly on the cavity to ensure good grounding;

[0050] The microwave digital board composite method also includes a radio frequency connector; the microwave signal enters through the radio frequency connector, the microwave signal first enters the microstrip line with only M5 layer and M6 layer, and then the microwave signal passes through the internal M5 layer of the microwave multilayer board and travels through the entire ten-layer microwave board. Finally, the microwave signal passes through the microstrip line with only M5 and M6 layers again and is finally transmitted out through the radio frequency connector.

[0051] The middle power layer and digital signals are transmitted to the side of the bare chip through the power layer and signal layer under the microwave layer, and provide power supply and control; the part of the microstrip line dug out is realized by digging holes.

[0052] The microwave digital board composite method also includes:

[0053] The power division circuit in the microwave multilayer board is used to distribute the microwave signal to multiple output paths, and each output path can independently control the power and switch state;

[0054] The power amplifier circuit in the microwave multilayer board is used to amplify the power of the microwave signal;

[0055] The switch circuit in the microwave multilayer board is used for switching the path or connection of the microwave signal;

[0056] The digital signal routing in the digital multilayer board is used to transmit digital signals and control signals to achieve control and regulation of the microwave circuit.

[0057] The microwave digital board composite method also includes:

[0058] The parameters of the microstrip line and the strip line on the front side of the composite board are adapted to the radio frequency characteristics of the radio frequency connector;

[0059] The selection and attachment method of the die are adapted to the performance and stability of the microwave circuit.

[0060] Vias and pads are also provided next to the bare chip, which are used to provide power and control signals for the bare chip.

[0061] This method can be applied to the combination of microwave circuits and digital circuits in various microwave frequency bands, greatly improving space utilization. One board can replace several previous boards, and the structure is simpler, realizing the integration and miniaturization of microwave circuits.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A microwave digital board composite method, characterized in that: include: A composite structure of ten layers of microwave boards and digital boards, wherein the stacking relationship of the microwave boards and the digital boards is a first digital multilayer board, a bare chip, a microwave multilayer board, and a second digital multilayer board; The microwave multilayer board is provided with an integrated TR circuit and a power division circuit; The digital signal and power layer dielectrics use common FR4 materials; the microwave circuit dielectric layer uses R04350, whose line width is adapted to the impedance.

2. The microwave digital board composite method according to claim 1 is characterized in that: The stacking relationship is as follows: The top layer and M2 layer use the same double-sided core material, the material is FR4, the copper foil thickness is 1oz, which is used for packaging device mounting and the power supply routing; The M3 and M4 layers use the same double-sided core material, the material is RO4350, the thickness is 4mil, the copper foil thickness is 0.5oz, and it is used for the digital signal routing; The M5 and M6 layers use the same double-sided core material, which is RO4350 with a thickness of 4 mil and a copper foil thickness of 0.5 oz, and is used for the microwave circuit, bare chip and digital circuit; The M7 and M8 layers use the same double-sided core material, the material is FR4, the copper foil thickness is 0.5oz, and is used for the digital signal routing; M9 and the bottom layer use the same double-sided core material, the material is FR4, the copper foil thickness is 0.5oz, and is used for the digital signal routing, bottom layer devices and routing.

3. The microwave digital board composite method according to claim 2 is characterized in that: The front side of the composite board of the ten-layer microwave board and the digital board is provided with a microstrip line and a strip line; The microstrip line in the M5 layer and the M6 ​​layer needs to be dug, from the M5 layer to the M6 ​​layer; the M5 layer carries a microwave circuit, and includes a power division circuit, a power amplifier circuit and a switch circuit; The M6 ​​layer is GND, and the position of the corresponding joint on the M6 ​​layer is dug from the bottom layer to the M6 ​​layer; and a metallization process of a preset thickness is performed on the M6 ​​layer for placing the bare chip.

4. The microwave digital board composite method according to claim 2 is characterized in that: It also includes a radio frequency connector; the microwave signal enters through the radio frequency connector, the microwave signal first enters the microstrip line with only M5 and M6 layers, then the microwave signal passes through the internal M5 layer of the microwave multilayer board, and travels through the entire ten-layer microwave board, and finally, the microwave signal passes through the microstrip line with only M5 and M6 layers again, and is finally transmitted out through the radio frequency connector.

5. The microwave digital board composite method according to claim 4, wherein the dug-out portion of the microstrip line is realized by digging a hole.

6. The microwave digital board composite method according to claims 1 to 5, further comprising: The power division circuit in the microwave multilayer board is used to distribute the microwave signal to multiple output paths, and each output path can independently control the power and switch state; The power amplifier circuit in the microwave multilayer board is used to amplify the power of the microwave signal; The switch circuit in the microwave multilayer board is used for switching the path or connection of the microwave signal; The digital signal routing in the digital multilayer board is used to transmit digital signals and control signals to achieve control and regulation of the microwave circuit.

7. The microwave digital board composite method according to claim 5, characterized in that: Further including: The parameters of the microstrip line and the strip line on the front side of the composite board are adapted to the radio frequency characteristics of the radio frequency connector; The selection and attachment method of the die are adapted to the performance and stability of the microwave circuit.

8. The microwave digital board composite method according to claims 1 to 7, characterized in that: Further including: Vias and pads are also provided next to the bare chip, and the vias and pads are used to provide power and control signals for the bare chip.

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