Packaging antenna based on three-dimensional stacking technology and antenna array

Abstract

The invention discloses a packaged antenna and an antenna array based on a three-dimensional stacking technology, belongs to the technical field of packaged antennas, and solves the problem that an existing antenna process is difficult to realize integrated packaging. The active device receives and sends radio frequency signals in an electrical connection mode, the interval height of the rewiring layers is limited within 50 micrometers, and the packaging requirement of the three-dimensional stacking technology is met. The microstrip feeder feeds signals to the antenna radiation patches in a coupled feeding mode, electrical connection is not needed, occupied space is reduced, the bandwidth of the antenna can be increased in a mode of overlapping a plurality of radiation patches, the performance of the antenna is further optimized, the space size of overall active packaging is fully utilized, the antenna and an active device are integrally packaged, and the antenna and the active device are integrally packaged. The packaging cost is reduced, the low-cost design of the packaged antenna is realized, and the packaging antenna has good application prospect and economic value.

Description

Technical Field

[0001] The present invention belongs to the technical field of packaged antennas, and relates to a packaged antenna and an antenna array based on three-dimensional stacking technology. Background Art

[0002] Packaged antenna (AiP) is based on packaging materials and processes, integrating antennas and chips in the package to achieve system and wireless functions. With the rapid development of 5G mobile communications, millimeter wave radar, terahertz and other technologies, the rapid development of packaged antenna technology has been promoted. Packaged antenna technology can well balance antenna performance, cost and volume, and is one of the important development directions of antenna technology in recent years.

[0003] At present, the research on package antenna technology mostly adopts low temperature co-fired ceramic (LTCC) process and high density interconnect (HDI) process. The two processes of LTCC and HDI are used for package antenna. The number of layers of the laminated substrate is large, and the metal hole connection between the laminated layers can be arbitrarily designed, which is very beneficial to the electrical performance design of the antenna. Another packaging process for package antenna design that is different from LTCC and HDI is the wafer-level fan-out packaging (FOWLP) process based on molding compound, which was first developed by Infineon. It does not require a laminated substrate like LTCC and HDI, but uses molding materials and reconfigured metal and dielectric layers. However, the FOWLP process has fewer metal layers that can be used for antenna design, which is not conducive to the design of package antenna.

[0004] When the existing LTCC or HDI process is used to design packaged antennas, the lamination and interlayer metallization electrical connection have a high degree of freedom, which is very beneficial to the electrical performance design of the antenna. However, the cost of these two processes for processing and manufacturing packaged antennas is still higher than that of conventional PCB processes. In addition, based on the design structure of the laminated substrate, it is difficult to integrate the antenna and active devices into an integrated package, and they are mostly integrated by surface mounting.

[0005] Three-dimensional stacking technology is a chip stacking technology used in semiconductor packaging. It is formed by stacking wafers on each other or chips on wafers. The layers are connected by silicon through holes to integrate chips produced by different processes into one package. There can be multiple redistribution layers (RDL layers) in the three-dimensional stacking technology. Reasonable use of RDL layers can be suitable for the design of packaged antennas. Although the three-dimensional stacking technology takes into account the overall packaging of active chips, it is affected by many factors such as electrical performance, manufacturing process, space limitations, thermal management, etc. Based on the three-dimensional stacking technology, there are strict restrictions on the number of layers of electrical connection, which cannot exceed 3 layers, and the thickness between the layers for internal electrical connection is ≤50 microns, and the total thickness that can achieve electrical connection is only 150 microns; and the antenna is a radiation structure, and the dielectric substrate of its feeder transmission needs a certain thickness, otherwise it will cause too much loss and too narrow bandwidth, and the thickness of a single layer of 50 microns as a dielectric substrate is far from enough for antenna design. The limitation of electrical connection and layer height greatly affects the working bandwidth design of the antenna. This limitation is also the main reason why the three-dimensional stacking technology has not been applied to antenna design.

[0006] At present, the single-layer thickness of ceramic sheets based on the LTCC process is 100 microns, and there is no limit on the stacking thickness, which can be stacked arbitrarily. Without the restrictions on thickness and stacking, there is basically no difficulty in antenna design; the HDI process is the same as the PCB process, and the minimum thickness of its dielectric substrate is ≮100 microns, and the high-frequency board thickness specifications used in the HDI process are also many, and a single layer can reach more than 1mm, and its total thickness can be achieved through arbitrary stacking.

[0007] In summary, the existing LTCC or HDI process is used to design packaged antennas. There are no restrictions on the thickness of a single-layer dielectric or the number of stacked layers, and the difficulty of antenna design is greatly reduced, and it can be achieved using conventional design ideas. However, the three-dimensional stacking technology is not conducive to antenna design under the strict restrictions of a single-layer thickness of 50 microns and a stacking of no more than 3 layers. Summary of the invention

[0008] The technical solution of the present invention is used to solve the problem that the existing antenna process is difficult to achieve integrated packaging.

[0009] The present invention solves the above technical problems through the following technical solutions:

[0010] A packaged antenna based on three-dimensional stacking technology, comprising a microstrip feed line, a transmission line, an active device, a first metal column, a second metal column, a third metal column, and a first package dielectric layer, a second package dielectric layer, a third package dielectric layer, a fourth package dielectric layer and a fifth package dielectric layer arranged in parallel from top to bottom;

[0011] An antenna radiation patch is arranged on the upper surface of the first packaging dielectric layer, a first metal ground is arranged between the first packaging dielectric layer and the second packaging dielectric layer, and a coupling gap is arranged on the first metal ground;

[0012] A first redistribution layer is provided between the second packaging dielectric layer and the third packaging dielectric layer, and a microstrip feed line is provided on the first redistribution layer;

[0013] A second redistribution layer is disposed between the third packaging dielectric layer and the fourth packaging dielectric layer, and a transmission line and a first metal plate are disposed on the second redistribution layer;

[0014] A third redistribution layer is disposed between the fourth packaging dielectric layer and the fifth packaging dielectric layer, and a second metal plate, a third metal plate and a fourth metal plate are disposed on the third redistribution layer;

[0015] Active devices are encapsulated in the fifth encapsulation dielectric layer, and a second metal ground is provided on the lower surface of the fifth encapsulation dielectric layer;

[0016] One end of the first metal column is connected to the microstrip feeder, and the other end of the first metal column passes through the first metal plate and is connected to the second metal plate, and the second metal plate is arranged on the radio frequency output end of the active device;

[0017] One end of the second metal column is connected to the third metal plate, the other end of the second metal column is connected to one end of the transmission line, the other end of the transmission line passes through the fourth metal plate and is connected to the RF input port on the second metal ground, and the third metal plate is arranged on the RF input end of the active device;

[0018] The first packaging dielectric layer, the second packaging dielectric layer, the third packaging dielectric layer, the fourth packaging dielectric layer, and the fifth packaging dielectric layer are integrally packaged.

[0019] Furthermore, the thickness of the third packaging dielectric layer and the fourth packaging dielectric layer are both less than or equal to 50 micrometers.

[0020] Furthermore, a plurality of first packaging dielectric layers may be stacked on the upper surface of the second packaging dielectric layer, and an antenna radiation patch is disposed on the upper surface of each first packaging dielectric layer.

[0021] Furthermore, the active device is any one of a low noise amplifier, an amplifier or an amplitude and phase multifunctional chip.

[0022] An antenna array comprises a plurality of antenna units and a microstrip multifunctional board, wherein the antenna units are packaged antennas based on three-dimensional stacking technology, and the plurality of antenna units are surface-mounted on the microstrip multifunctional board.

[0023] The advantages of the present invention are:

[0024] The present invention forms an electrical connection channel between the three layers of redistribution layers through metal columns and feeders, so that the active device receives and sends radio frequency signals through electrical connection, and limits the spacing height of each redistribution layer to within 50 microns, meeting the packaging requirements of the three-dimensional stacking technology; the microstrip feeder feeds the signal to the antenna radiation patch through coupled feeding, without the need for electrical connection, reducing space occupancy, and can increase the antenna bandwidth by superimposing multiple radiation patches, further optimizing the antenna performance, making full use of the spatial size of the overall active package, integrating the antenna and the active device into a package, reducing the packaging cost, and realizing the low-cost design of the packaged antenna, which has good application prospects and economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a structural diagram of a packaged antenna based on three-dimensional stacking technology according to a first embodiment of the present invention;

[0026] Figure 2 is a schematic diagram of a packaged antenna with multiple first packaged dielectric layers stacked in accordance with the first embodiment of the present invention;

[0027] Figure 3 is a curve diagram of the standing wave simulation of the packaged antenna according to the first embodiment of the present invention;

[0028] Figure 4 This is a structural diagram of a packaged antenna array based on three-dimensional stacking technology according to a second embodiment of the present invention;

[0029] Figure 5 is the scanning pattern of the packaged antenna array of the second embodiment of the present invention at a frequency of 12.5 GHz;

[0030] Figure numerals: 11, antenna radiation patch; 12, first metal ground; 13, first redistribution layer; 14, second redistribution layer; 15, third redistribution layer; 16, second metal ground; 21, first packaging dielectric layer; 22, second packaging dielectric layer; 23, third packaging dielectric layer; 24, fourth packaging dielectric layer; 25, fifth packaging dielectric layer; 31, active device; 41, RF input port; 51, first metal column; 52, second metal column; 53, third metal column; 54, first metal disk; 55, second metal disk; 56, third metal disk; 57, fourth metal disk; 61, coupling gap; 62, microstrip feed line; 63, transmission line; 71, microstrip multi-function board. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments:

[0033] Embodiment 1

[0034] like Figure 1 As shown, specifically, a packaged antenna based on three-dimensional stacking technology is disclosed, including a microstrip feed line 62, a transmission line 63, an active device 31, a first metal column 51, a second metal column 52, a third metal column 53, and a first package dielectric layer 21, a second package dielectric layer 22, a third package dielectric layer 23, a fourth package dielectric layer 24 and a fifth package dielectric layer 25 arranged in parallel from top to bottom;

[0035] An antenna radiation patch 11 is disposed on the upper surface of the first packaging dielectric layer 21, a first metal ground 12 is disposed between the first packaging dielectric layer 21 and the second packaging dielectric layer 22, and a coupling gap 61 is disposed on the first metal ground 12;

[0036] A first redistribution layer 13 is disposed between the second packaging dielectric layer 22 and the third packaging dielectric layer 23, and a microstrip feed line 62 is disposed on the first redistribution layer 13;

[0037] A second redistribution layer 14 is disposed between the third packaging dielectric layer 23 and the fourth packaging dielectric layer 24, and a transmission line 63 and a first metal plate 54 are disposed on the second redistribution layer 14;

[0038] A third redistribution layer 15 is disposed between the fourth packaging dielectric layer 24 and the fifth packaging dielectric layer 25, and a second metal plate 55, a third metal plate 56 and a fourth metal plate 57 are disposed on the third redistribution layer 15;

[0039] The active device 31 is encapsulated in the fifth encapsulation dielectric layer 25, and the lower surface of the fifth encapsulation dielectric layer 25 is provided with a second metal ground 16;

[0040] One end of the first metal column 51 is connected to the microstrip feed line 62, and the other end of the first metal column 51 passes through the first metal plate 54 and is connected to the second metal plate 55, and the second metal plate 55 is arranged on the RF output end of the active device 31;

[0041] One end of the second metal column 52 is connected to the third metal plate 56, the other end of the second metal column 52 is connected to one end of the transmission line 63, the other end of the transmission line 63 passes through the fourth metal plate 57 and is connected to the RF input port 41 on the second metal ground 16, and the third metal plate 56 is arranged on the RF input end of the active device 31;

[0042] The first packaging dielectric layer 21 , the second packaging dielectric layer 22 , the third packaging dielectric layer 23 , the fourth packaging dielectric layer 24 , and the fifth packaging dielectric layer 25 are integrally packaged.

[0043] Furthermore, a plurality of the first packaging dielectric layers 21 may be stacked on the upper surface of the second packaging dielectric layer 22 , and an antenna radiation patch 11 is disposed on the upper surface of each of the first packaging dielectric layers 21 .

[0044] like Figure 2 The packaged antenna model is formed by stacking multiple first package dielectric layers 21. Two first package dielectric layers 21 are stacked on the upper surface of the second package dielectric layer 22. The upper surface of each first package dielectric layer 21 is provided with an antenna radiation patch 11. Multiple first package dielectric layers 21 can be stacked according to the bandwidth requirements of the actual antenna.

[0045] Figure 2 Two H-shaped coupling slots 61 are arranged on the first metal ground 12 , and two microstrip feed lines 62 are arranged on the first redistribution layer 13 . When the antenna and the active device 31 are packaged as one, the microstrip feed lines 62 and the active device 31 are electrically connected through the first metal column 51 .

[0046] Furthermore, the active device 31 is any one of a low noise amplifier, an amplifier or an amplitude and phase multifunctional chip.

[0047] The antenna radiation patch 11 is an independent metal layer without electrical connection. As the radiation structure of the packaged antenna, the first packaging dielectric layer 21 is specifically a dielectric substrate. Since the antenna radiation patch 11 has no electrical connection, there is no special requirement for the thickness of the first packaging dielectric layer 21. The number of antenna radiation patches 11 arranged on the upper surface of each first packaging dielectric layer 21 is ≥1.

[0048] The first metal ground 12 is the metal ground of the antenna radiation patch 11. By setting a coupling gap 61 on the first metal ground 12, the antenna radiation patch 11 can be coupled and fed, thereby reducing the electrical connection of the antenna feeding structure. Since the first metal ground 12 has no electrical connection with the antenna radiation patch 11, there is no special requirement for the thickness of the second packaging dielectric layer 22, which effectively improves the freedom of antenna design.

[0049] Furthermore, the thickness of the third packaging dielectric layer 23 and the fourth packaging dielectric layer 24 are both less than or equal to 50 micrometers.

[0050] The first redistribution layer 13 is used to arrange the microstrip feed line 62. The microstrip feed line 62 on the first redistribution layer is electrically connected to the RF output end of the active device 31 in the rear-end package through a metal column. Since the dielectric substrate where the first redistribution layer 13 is located is electrically connected, the thickness of the third packaging dielectric layer 23 needs to meet the requirement of ≤50 microns.

[0051] The second redistribution layer 14 is used to arrange a transmission line 63 connecting the active device 31 and the RF input port 41 and a metal plate for connecting the metal column. The transmission line 63 is connected to the RF input end of the active device 31 through the second metal column 52, and is connected to the RF input port 41 on the second metal ground 16 through the third metal column 53. The transmission line 63 is used to receive and transmit RF signals. Since the dielectric substrate where the second redistribution layer 14 is located is electrically connected, the thickness of the fourth packaging dielectric layer 24 must also meet ≤50 microns.

[0052] The third redistribution layer 15 is used to arrange metal pads of metal pillars. The metal pads are used to ensure that the metal pillars can pass through the redistribution layer. The metal pillars can provide contact points and are designed to avoid direct contact between the metal pillars and the conductive paths in the wiring layer.

[0053] In this embodiment, the area below the third redistribution layer 15 is a packaging area for the active device 31 , and the thickness of the fifth packaging dielectric layer 25 is determined according to the thickness of the active device 31 .

[0054] In this embodiment, the first rewiring layer 13, the second rewiring layer 14 and the third rewiring layer 15 with electrical connection properties that can be allocated to the antenna design are limited by the packaging process, and the interlayer height needs to be limited to within 50 microns, that is, the thickness of the third packaging dielectric layer 23 and the fourth packaging dielectric layer 24 are both less than or equal to 50 microns. The processing technology of the metal column of the fifth packaging dielectric layer 25 where the active device 31 is located is different from that of the first to third rewiring layers, and the fifth packaging dielectric layer 25 is the packaging area of ​​the active device 31. Therefore, the thickness of the dielectric substrate (fifth packaging dielectric layer 25) where the third rewiring layer is located may not be limited to 50 microns, and the thickness of the fifth packaging dielectric layer 25 can be used to expand the overall thickness of the antenna feeder layer, further improving the freedom of antenna design, and meeting the requirements of antenna design while meeting the requirements of three-dimensional stacking technology for thickness and number of layers.

[0055] like Figure 3 2 is a standing wave simulation result of the packaged antenna unit. It can be seen that the packaged antenna unit provided in this embodiment has good matching characteristics in the 10.5-13 GHz frequency band.

[0056] Working principle:

[0057] The active device 31 located in the fifth packaging dielectric layer 25 receives the RF input signal through the second metal column 52, the transmission line 63 and the third metal column 53 in turn, and the active device 31 transmits the RF signal to the microstrip feeder 62 through the first metal column 51, and transmits the RF signal to the antenna radiation patch 11 through the microstrip feeder 62. A stable electrical path is formed in the first to third redistribution layers through the feeder and the metal columns, and signal crosstalk and short circuit are avoided through the physically isolated dielectric layer, thereby improving the signal quality. At the same time, the spacing height of each redistribution layer is limited to within 50 microns, meeting the packaging requirements of the three-dimensional stacking technology, and realizing the integrated packaging of the antenna and the active chip.

[0058] The antenna radiation patch 11 on the first packaging dielectric layer 21 converts the fed RF signal into an electromagnetic radiation wave. Even if it has no electrical connection with the second packaging dielectric layer 22, it can be coupled with the feeder signal of the microstrip feeder 62 through the coupling gap 61, thereby reducing the number of electrical connections and increasing the degree of freedom in design. When the actual antenna bandwidth requires, multiple first packaging dielectric layers 21 and antenna radiation patches 11 can be stacked to increase the antenna bandwidth and gain, thereby further optimizing the antenna performance.

[0059] Embodiment 2

[0060] The present invention also provides an antenna array, including multiple antenna units and a microstrip multifunctional board 71 , wherein the antenna units are packaged antennas based on three-dimensional stacking technology provided in one embodiment, and the multiple antenna units are surface-mounted on the microstrip multifunctional board 71 .

[0061] like Figure 4 In this embodiment, multiple antenna units are combined into an 8×8 antenna array and surface-mounted on a microstrip multifunctional board 71. Figure 5 The scanning pattern of the packaged antenna array at the 12.5 GHz frequency point can achieve a 60-degree beam scanning capability.

[0062] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A packaged antenna based on three-dimensional stacking technology, characterized in that: It comprises a microstrip feed line (62), a transmission line (63), an active device (31), a first metal column (51), a second metal column (52), a third metal column (53), and a first packaging dielectric layer (21), a second packaging dielectric layer (22), a third packaging dielectric layer (23), a fourth packaging dielectric layer (24), and a fifth packaging dielectric layer (25) arranged in parallel from top to bottom; An antenna radiation patch (11) is provided on the upper surface of the first packaging dielectric layer (21), a first metal ground (12) is provided between the first packaging dielectric layer (21) and the second packaging dielectric layer (22), and a coupling gap (61) is provided on the first metal ground (12); A first redistribution layer (13) is provided between the second packaging dielectric layer (22) and the third packaging dielectric layer (23), and a microstrip feed line (62) is provided on the first redistribution layer (13); A second redistribution layer (14) is provided between the third packaging dielectric layer (23) and the fourth packaging dielectric layer (24), and a transmission line (63) and a first metal plate (54) are provided on the second redistribution layer (14); A third redistribution layer (15) is provided between the fourth packaging dielectric layer (24) and the fifth packaging dielectric layer (25), and a second metal plate (55), a third metal plate (56) and a fourth metal plate (57) are provided on the third redistribution layer (15); The active device (31) is encapsulated in the fifth encapsulation dielectric layer (25), and a second metal ground (16) is provided on the lower surface of the fifth encapsulation dielectric layer (25); One end of the first metal column (51) is connected to a microstrip feed line (62), and the other end of the first metal column (51) passes through a first metal plate (54) and is connected to a second metal plate (55), and the second metal plate (55) is arranged on a radio frequency output end of the active device (31); One end of the second metal column (52) is connected to the third metal plate (56), the other end of the second metal column (52) is connected to one end of the transmission line (63), the other end of the transmission line (63) passes through the fourth metal plate (57) and is connected to the radio frequency input port (41) on the second metal ground (16), and the third metal plate (56) is arranged on the radio frequency input end of the active device (31); The first packaging dielectric layer (21), the second packaging dielectric layer (22), the third packaging dielectric layer (23), the fourth packaging dielectric layer (24), and the fifth packaging dielectric layer (25) are packaged in an integrated manner.

2. The packaged antenna based on three-dimensional stacking technology according to claim 1, characterized in that: The thickness of the third packaging dielectric layer (23) and the fourth packaging dielectric layer (24) are both less than or equal to 50 micrometers.

3. The packaged antenna based on three-dimensional stacking technology according to claim 2, characterized in that: A plurality of first packaging medium layers (21) may be stacked on the upper surface of the second packaging medium layer (22), and an antenna radiation patch (11) is provided on the upper surface of each first packaging medium layer (21).

4. The packaged antenna based on three-dimensional stacking technology according to claim 2, characterized in that: The active device (31) is any one of a low noise amplifier, an amplifier or an amplitude and phase multifunctional chip.

5. An antenna array, characterized in that: It comprises a plurality of antenna units and a microstrip multifunctional board (71), wherein the antenna unit is a packaged antenna based on three-dimensional stacking technology as described in any one of claims 1 to 4, and the plurality of antenna units are surface-mounted on the microstrip multifunctional board (71).

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