A package antenna and antenna array based on three-dimensional stacking technology

Abstract

The application relates to a packaging antenna based on a three-dimensional stacking technology and an antenna array, belongs to the technical field of packaging antennas, and solves the problem that existing antenna processes are difficult to realize integrated packaging; the application forms an electrical connection channel between three layers of rewiring layers through metal columns and feed lines, enables an active device to receive and send radio frequency signals in an electrical connection mode, limits the interval height of the rewiring layers to be within 50 microns, meets the packaging requirements of the three-dimensional stacking technology, feeds signals to antenna radiation patches in a coupling feeding mode through microstrip feed lines, does not need electrical connection, reduces space occupation, can increase the antenna bandwidth in a manner of stacking multiple radiation patches, further optimizes the antenna performance, fully utilizes the space size of the overall active packaging, integrates the antenna and the active device, reduces the packaging cost, realizes low-cost design of the packaging antenna, and has good application prospect and economic value.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of packaging antennas, and relates to a packaging antenna based on a three-dimensional stacking technology and an antenna array. BACKGROUND

[0002] A packaging antenna (AiP) is based on packaging materials and processes to integrate an antenna and a chip in a package, thereby realizing system and wireless functions. With the rapid development of 5G mobile communication, millimeter wave radar, terahertz and other technologies, the packaging antenna technology has been rapidly developed. The packaging antenna technology can well balance the antenna performance, cost and size, and is one of the important development directions of antenna technology in recent years.

[0003] At present, the research on packaging antenna technology mostly adopts low-temperature co-fired ceramic (LTCC) technology and high-density interconnection (HDI) technology. The LTCC and HDI technologies have more layers of laminated substrates and the metal hole connection between the laminated layers can be designed at will, which is very beneficial to the electrical performance design of the antenna. Another packaging process different from LTCC and HDI for packaging antenna design is wafer-level fan-out packaging (FOWLP) based on molding compound. It was first developed by Infineon, which does not need laminated substrates like LTCC and HDI, but uses molding materials, reconfigures 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 packaging antennas.

[0004] When the existing LTCC or HDI process is used to design a packaging antenna, the layer and interlayer metallization electrical connection has high freedom, which is very beneficial to the electrical performance design of the antenna. However, the processing and manufacturing cost of these two processes for packaging antennas is still higher than that of the conventional PCB process, and the design structure based on laminated substrates makes it difficult to integrate the antenna and active devices, and the surface mounting method is mostly used for integration.

[0005] Three-dimensional stacking technology is a chip stacking technology for semiconductor packaging, which is stacked by wafers or chips and wafers, and is connected by through silicon via between layers to integrate wafers produced by different processes in one package. In three-dimensional stacking technology, there can be multiple redistribution layers (RDL layers), and reasonable use of RDL layers can be suitable for the design of packaged antennas. Although three-dimensional stacking technology considers the overall packaging of active chips, it is affected by many factors such as electrical performance, manufacturing process, space limitation, thermal management, etc. Based on three-dimensional stacking technology, the number of layers of electrical connection is strictly limited to no more than 3 layers, and the thickness between layers for internal electrical connection is ≤50 microns, and the total thickness that can achieve electrical connection is only 150 microns; and as a radiation structure, the medium substrate of the feed line 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 layer of medium substrate for antenna design is far from enough. The limitation of electrical connection and layer height greatly affects the design of the working bandwidth of the antenna, and this limitation is the main reason why three-dimensional stacking technology is not applied to antenna design.

[0006] At present, the single-layer thickness of the ceramic sheet based on the LTCC process is 100 microns, and the stack thickness has no limit and can be stacked arbitrarily. There is no difficulty in antenna design without the limitation of thickness and stack. The minimum thickness of the medium substrate of the HDI process is similar to that of the PCB process, which is >100 microns, and the thickness specification of the high-frequency board material used in the HDI process is also large, and the single layer can reach more than 1 mm, and the total thickness can be realized by arbitrary stacking.

[0007] In summary, using existing LTCC or HDI process for packaging antenna design, the single-layer medium thickness and the number of layers of the stack have no limit, and the difficulty of antenna design is greatly reduced, and a conventional design approach can be used. Under the strict limitation of three-dimensional stacking technology with a single-layer thickness of 50 microns and a stack of no more than 3 layers, it is not conducive to antenna design. SUMMARY

[0008] The technical solution of the present application solves the problem that the existing antenna process cannot realize integrated packaging.

[0009] The present application solves the above technical problems by 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 packaging medium layer, a second packaging medium layer, a third packaging medium layer, a fourth packaging medium layer and a fifth packaging medium layer arranged in parallel from top to bottom.

[0011] An antenna radiation patch is provided on the upper surface of the first packaging dielectric layer, a first metal ground is provided between the first packaging dielectric layer and the second packaging dielectric layer, and a coupling gap is provided 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 provided between the third packaging dielectric layer and the fourth packaging dielectric layer, and a transmission line and a first metal plate are provided on the second redistribution layer;

[0014] A third redistribution layer is provided 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 provided 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 provided on the radio frequency output end of the active device;

[0017] One end of the second metal pillar is connected to the third metal plate, the other end of the second metal pillar 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 provided 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 microns.

[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 provided 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 includes multiple antenna units and a microstrip multifunctional board. The antenna units are packaged antennas based on three-dimensional stacking technology. Multiple antenna units are surface-mounted on the microstrip multifunctional board.

[0023] The advantages of the present invention are:

[0024] The application forms an electrical connection channel between three re-distribution layers through metal columns and feed lines, so that the active device receives and transmits radio frequency signals in an electrical connection mode, the interval height of each re-distribution layer is limited to within 50 microns, the packaging requirement of three-dimensional stacking technology is met, the microstrip feed line feeds signals to the antenna radiation patch in a coupling feeding mode, without electrical connection, the space occupation is reduced, the antenna bandwidth can be increased by stacking multiple radiation patches, the antenna performance is further optimized, the space size of the overall active package is fully utilized, the antenna and the active device are integrated and packaged, the packaging cost is reduced, the low-cost design of the packaged antenna is realized, and the application prospect and economic value are good. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a structure diagram of a packaged antenna based on three-dimensional stacking technology according to an embodiment of the application;

[0026] Figure 2 is a schematic diagram of a packaged antenna in which multiple first packaging medium layers are stacked according to the embodiment of the application;

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

[0028] Figure 4 is a structure diagram of a packaged antenna array based on three-dimensional stacking technology according to an embodiment of the application;

[0029] Figure 5 is a scanning directional diagram of the packaged antenna array according to the embodiment of the application at a frequency point of 12.5 GHz;

[0030] The drawings show that: 11, antenna radiation patch; 12, first metal ground; 13, first re-distribution layer; 14, second re-distribution layer; 15, third re-distribution layer; 16, second metal ground; 21, first packaging medium layer; 22, second packaging medium layer; 23, third packaging medium layer; 24, fourth packaging medium layer; 25, fifth packaging medium layer; 31, active device; 41, radio frequency input port; 51, first metal column; 52, second metal column; 53, third metal column; 54, first metal disc; 55, second metal disc; 56, third metal disc; 57, fourth metal disc; 61, coupling gap; 62, microstrip feed line; 63, transmission line; 71, microstrip multifunctional board. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

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

[0033] Example 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 pillar 51, a second metal pillar 52, a third metal pillar 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;

[0035] 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 ;

[0036] 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 ;

[0037] 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 ;

[0038] 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 ;

[0039] 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 ;

[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. The second metal plate 55 is provided on the RF output end of the active device 31.

[0041] One end of the second metal column 52 is connected with the third metal disc 56, the other end of the second metal column 52 is connected with one end of the transmission line 63, the other end of the transmission line 63 is connected with the radio frequency input port 41 on the second metal ground 16 through the fourth metal disc 57, and the third metal disc 56 is arranged on the radio frequency input end of the active device 31.

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

[0043] Further, the upper surface of the second packaging medium layer 22 can be stacked with a plurality of first packaging medium layers 21, and the upper surface of each first packaging medium layer 21 is provided with an antenna radiation patch 11.

[0044] As Figure 2 The packaging antenna model formed by stacking a plurality of first packaging medium layers 21 is that two first packaging medium layers 21 are stacked on the upper surface of the second packaging medium layer 22, and the upper surface of each first packaging medium layer 21 is provided with an antenna radiation patch 11. According to the actual bandwidth requirement of the antenna, a plurality of first packaging medium layers 21 can be stacked.

[0045] Figure 2 The first metal ground 12 is provided with two H-shaped coupling slots 61, and the first redistribution layer 13 is provided with two microstrip feed lines 62. When the antenna is integrally packaged with the active device 31, the microstrip feed line 62 is electrically connected to the active device 31 through the first metal column 51.

[0046] Further, 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, which serves as a radiation structure of the packaging antenna. The first packaging medium layer 21 is a dielectric substrate. Since the antenna radiation patch 11 is not electrically connected, the thickness of the first packaging medium layer 21 has no special requirement. The number of antenna radiation patches 11 arranged on the upper surface of each first packaging medium layer 21 is greater than or equal to 1.

[0048] The first metal ground 12 is a metal ground of the antenna radiation patch 11. By arranging the coupling slot 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 feed structure. Since the first metal ground 12 is not electrically connected to the antenna radiation patch 11, the thickness of the second packaging medium layer 22 also has no special requirement, which effectively improves the degree of freedom of antenna design.

[0049] Further, the thickness of the third packaging medium layer 23 and the fourth packaging medium layer 24 is less than or equal to 50 microns.

[0050] The first redistribution layer 13 is used to arrange the microstrip feed line 62, and the microstrip feed line 62 on the first redistribution layer is electrically connected to the radio frequency output end of the active device 31 of the back-end package through the metal column. Since the medium substrate where the first redistribution layer 13 is located has electrical connection, the thickness of the third packaging medium layer 23 needs to meet ≤50 microns.

[0051] The second redistribution layer 14 is used to arrange the transmission line 63 connecting the active device 31 and the radio frequency input port 41, and the metal disc for connecting the metal column. The transmission line 63 is connected to the radio frequency input end of the active device 31 through the second metal column 52, and is connected to the radio frequency 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 radio frequency signals. Since the medium substrate where the second redistribution layer 14 is located has electrical connection, the thickness of the fourth packaging medium layer 24 also needs to meet ≤50 microns.

[0052] The third redistribution layer 15 is used to arrange the metal disc of the metal column, which is used to ensure that the metal column can pass through the redistribution layer. The metal column can provide a contact point, and in the design, the metal column is avoided from directly contacting the conductive path in the wiring layer.

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

[0054] In the embodiment, the first redistribution layer 13, the second redistribution layer 14 and the third redistribution 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 within 50 microns, that is, the thickness of the third packaging medium layer 23 and the fourth packaging medium layer 24 is less than or equal to 50 microns. The processing technology of the metal column of the fifth packaging medium layer 25 where the active device 31 is located is different from the processing technology of the first to third redistribution layers, and the fifth packaging medium layer 25 is the packaging area of the active device 31. Therefore, the thickness of the medium substrate (the fifth packaging medium layer 25) where the third redistribution layer is located can not be limited by 50 microns. The overall thickness of the antenna feed line layer can be expanded by using the thickness of the fifth packaging medium layer 25, and the degree of freedom of the antenna design is further improved. The thickness and the number of layers meet the requirements of the three-dimensional stacking technology, and meet the requirements of the antenna design.

[0055] As shown in FIG. 6, the first redistribution layer 13, the second redistribution layer 14 and the third redistribution layer 15 are arranged in the packaging area of the active device 31. Figure 3 For the simulation results of the packaged antenna unit, it can be seen that the packaged antenna unit provided in the embodiment has good matching characteristics in the frequency band of 10.5-13 GHz.

[0056] Working principle:

[0057] The active device 31 located at the fifth packaging medium layer 25 receives the radio frequency 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 radio frequency signal to the microstrip feed line 62 through the first metal column 51, and the radio frequency signal is transmitted to the antenna radiation patch 11 through the microstrip feed line 62, and a stable electrical path is formed in the first to third redistribution layers through the feed line and the metal column, and the signal crosstalk and short circuit are avoided through the physically isolated medium layer, and the signal quality is improved; at the same time, the interval height of each redistribution layer is limited to within 50 microns, which meets the packaging requirements of the three-dimensional stacking technology, and realizes the integrated packaging of the antenna and the active chip.

[0058] The antenna radiation patch 11 on the first packaging medium layer 21 converts the fed radio frequency signal into electromagnetic radiation wave, that is, even if there is no electrical connection with the second packaging medium layer 22, the feed line signal coupling of the coupling gap 61 and the microstrip feed line 62 can be realized, the number of electrical connections is reduced, and the design freedom is increased; when the actual antenna bandwidth is required, multiple first packaging medium layers 21 and antenna radiation patches 11 can be stacked to increase the antenna bandwidth and gain, and the antenna performance is further optimized.

[0059] Embodiment two

[0060] The application also provides an antenna array, which comprises a plurality of antenna units and a microstrip multifunctional board 71, the antenna units are the packaging antenna based on the three-dimensional stacking technology provided in the embodiment, and the plurality of antenna units are attached to the microstrip multifunctional board 71.

[0061] As Figure 4 For this embodiment, the plurality of antenna units form an 8x8 antenna array, which is attached to the microstrip multifunctional board 71, Figure 5 For the scanning directional diagram of the packaging antenna array at a frequency point of 12.5GHz, a 60-degree beam scanning capability can be realized.

[0062] The above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application.

Claims

1. A packaged antenna based on three-dimensional stacking technology, characterized in that: It includes 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 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 radio frequency output end of the active device (31); One end of the second metal column (52) is connected to the third metal disk (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 disk (57) and is connected to the radio frequency input port (41) on the second metal ground (16), and the third metal disk (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 integrally packaged.

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 microns.

3. The packaged antenna based on three-dimensional stacking technology according to claim 2, characterized in that: A plurality of 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 provided on the upper surface of each first packaging dielectric layer (21).

4. The packaged antenna based on three-dimensional stacking technology according to claim 2, characterized in that: The active device (31) is an amplifier or an amplitude-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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