A glass-based panel-level analog-digital hybrid transceiver front-end array

Abstract

The application discloses a glass-based panel-level digital-analog hybrid transceiver front-end array, comprising a panel-level glass substrate, a plurality of radio frequency transceiver units, a power amplifier and switch unit, a power management and clock distribution network, a passive device network, a panel-level antenna array and a panel-level package. The glass panel has extremely low dielectric loss in the millimeter wave frequency band, and in combination with high-precision RDL, realizes ultra-low-loss radio frequency signal transmission between chips and between chips and antennas, and improves system efficiency and effective isotropic radiated power (EIRP). By using the flatness of the glass panel and the panel-level process, three-dimensional heterogeneous integration of antennas, radio frequencies, analogs, digital, power and passive devices is realized, and a complete panel-level microsystem is realized, and the volume and weight are greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of advanced packaging technology, and in particular relates to a glass-based panel-level hybrid digital-analog transceiver front-end array. Background Technology

[0002] With the large-scale commercialization of 5G mobile communication and the rapid iteration of 6G mobile communication, millimeter-wave imaging radar, and low-orbit satellite internet technologies, the market has placed stringent demands on the integration, operating bandwidth, transmission efficiency, beam control capabilities, and mass production costs of RF transceiver front-end modules. The millimeter-wave band, with its advantages of large bandwidth, high transmission rate, and low latency, is the core band for next-generation wireless communication technology. However, high-frequency signal transmission is prone to problems such as interconnection loss, signal crosstalk, and integrity failure. Furthermore, multi-channel large-scale array integration faces technical challenges such as heat dissipation difficulties, low packaging reliability, and challenges in miniaturizing the structure.

[0003] Currently, most mainstream RF front-ends use silicon-based or compound semiconductor chips combined with traditional system-in-package (SiP) solutions for integration. This approach is mature in low-frequency applications, but it has significant shortcomings when adapting to millimeter-wave frequencies: high dielectric loss of organic substrates leads to severe high-frequency signal transmission loss; insufficient substrate wiring precision cannot meet the requirements of high-density array integration; the substrate's thermal expansion coefficient differs greatly from that of silicon chips, easily generating thermal stress under alternating hot and cold conditions, resulting in reliability issues such as chip desoldering and wiring breakage; and traditional single-chip SiP packaging and wafer-level packaging have low mass production efficiency and high single-channel cost, making them difficult to adapt to large-scale array application scenarios.

[0004] Glass, as a core substrate for next-generation advanced packaging, possesses significant advantages such as extremely low dielectric loss in millimeter waves, a thermal expansion coefficient highly matched to silicon chips, high surface flatness, the ability to be processed into large-area panels, and controllable costs. It can be used to fabricate high-precision redistribution layers and vertical glass via interconnect structures, perfectly meeting the high-frequency, high-density, and low-loss transmission requirements of millimeter waves. However, the industry has not yet achieved deep integration of glass-based panel-level packaging with mixed-signal transceiver functionality. The lack of a complete millimeter-wave transceiver front-end array solution integrating antennas, RF, digital, power, and passive matching networks has become a core challenge restricting the miniaturization, high-performance, and low-cost mass production of large-scale millimeter-wave phased array systems. Summary of the Invention

[0005] Purpose of the Invention: The purpose of this invention is to provide a mixed-signal transceiver front-end array based on a glass-based panel-level package. This array is designed to achieve high integration, low loss, and high reliability of multi-channel RF signal transmission and reception, and is particularly suitable for millimeter-wave massive MIMO systems and phased array systems, while also offering significant cost advantages.

[0006] Technical solution: The present invention provides a glass-based panel-level mixed analog-digital transceiver front-end array, comprising: a panel-level glass substrate, several radio frequency transceiver units, power amplification and switching units, a power management and clock distribution network, a passive device network, a panel-level antenna array, and a panel-level package. The panel-level glass substrate has a double-layer structure, including a glass antenna layer and a glass functional layer. The glass antenna layer and the glass functional layer are evenly distributed with redistribution layers for horizontal electrical interconnection and glass vias for vertical electrical interconnection and auxiliary heat dissipation. Several radio frequency transceiver units are arranged in an array and integrated on the upper surface of the glass functional layer. Each radio frequency transceiver unit integrates a mixed-signal SoC, a receiving low-noise amplifier circuit, a transmitting drive amplifier circuit, an analog frequency conversion circuit, and a frequency source circuit to construct a complete mixed-signal radio frequency transceiver link. The power amplification and switching unit is integrated on the upper surface of the glass functional layer, between the radio frequency transceiver unit and the panel-level antenna array, and is used to realize the power amplification of the transmitted signal and the switching of the antenna transceiver channel. The power management and clock distribution network is deployed on the lower surface of the glass functional layer, the redistribution layer, and inside the glass vias, providing stable power supply and synchronous low-jitter clock signals for all active devices in the array; The passive device network is integrated with the glass functional layer’s redistribution layer and glass vias to achieve signal impedance matching, filtering and bias power supply functions. The panel-level antenna array is integrally fabricated on the upper surface of the glass antenna layer, and direct power is achieved through the redistribution layer built into the glass antenna layer and the glass via. The panel-level package covers the outside of the overall structure, and only exposes the radiating surface of the panel-level antenna array, thereby achieving protection and enhanced reliability of the overall structure.

[0007] Furthermore, the mixed-signal SoC integrates a digital baseband processor, a high-speed data converter, and an RF transceiver. The digital baseband processor has a built-in DBF digital beamforming algorithm unit for digital domain weighting and phase shifting of multi-channel transceiver signals.

[0008] Furthermore, the minimum linewidth / spacing specification of the redistribution layer is 2μm / 2μm or less, which meets the requirements of millimeter-wave high-frequency high-density integrated transmission.

[0009] Furthermore, the radio frequency transceiver unit is interconnected with the glass functional layer through microbumps with a spacing of less than 100 μm.

[0010] Furthermore, the panel-level antenna array operates in the frequency band of 30 GHz to 100 GHz.

[0011] Furthermore, the inner wall of the glass via is metallized to provide vertical signal interconnection and enhance heat dissipation.

[0012] Furthermore, the mixed-signal SoC is integrated onto the upper surface pads of the glass functional layer via flip-chip bonding, the power amplifier microwave integrated circuit and the switching microwave integrated circuit are integrated onto the upper surface pads of the glass functional layer via wire bonding, and the power management chip is integrated onto the lower surface solder balls / pads of the glass functional layer via flip-chip bonding.

[0013] Furthermore, the glass antenna layer and the glass functional layer are integrated in three dimensions by laser bonding through corresponding bonding regions.

[0014] A method for fabricating a glass-based panel-level hybrid digital-analog transceiver front-end array includes: forming and metallizing glass vias on a glass antenna layer and a glass functional layer; fabricating multiple high-density redistribution layers on the surfaces of the glass antenna layer and the glass functional layer; fabricating a planar antenna array pattern on the surface of the glass antenna layer; assembling radio frequency transceiver units, power amplifiers and switching units, and power management units to designated positions on the glass functional layer; achieving three-dimensional stacking of the glass antenna layer and the glass functional layer through laser bonding; and performing panel-level molding encapsulation to expose the antenna radiating surface.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) High performance and low loss: The dielectric loss of the glass panel in the millimeter wave band is extremely low. Combined with the high-precision RDL, it realizes ultra-low loss radio frequency signal transmission between chips and between chips and antennas, which improves system efficiency and effective omnidirectional radiated power (EIRP).

[0016] (2) High integration and miniaturization: By utilizing the flatness of the glass panel and panel-level technology, antenna, radio frequency, analog, digital, power and passive devices are three-dimensionally heterogeneously integrated to realize a complete panel-level microsystem, which greatly reduces the size and weight.

[0017] (3) Excellent thermal management and reliability: The CTE of the glass matches that of the silicon chip, reducing thermal stress and improving long-term reliability. TGV and panel-level structure facilitate uniform heat dissipation.

[0018] (4) Significant cost advantages: Using large-area panel-level manufacturing (e.g., 510mm×515mm panel), hundreds or thousands of array units can be packaged at one time, resulting in extremely high production efficiency. The packaging cost is spread to the lowest level through the area effect, making it economical for large-scale mass production. The unit cost is much lower than that of traditional wafer-level packaging (WLP) or single-chip SiP packaging.

[0019] (5) Flexible design and strong scalability: The glass panel has strong process compatibility, which facilitates the integration of chips with different process nodes (such as GaAs low noise amplifier chips, GaN power amplifier chips, InP mixer chips, CMOS power management chips, etc.). The array size can be freely expanded at the panel level according to the needs, which facilitates the realization of large-scale antenna arrays.

[0020] (6) System simplification and performance improvement: The antenna and front-end circuit are integrated into one, eliminating the uncertainty and loss caused by the high-frequency connector, improving the consistency and stability of the overall system performance, and making it easier to achieve precise beam control. Attached Figure Description

[0021] Figure 1 This is a top view schematic diagram of a glass-based panel-level hybrid digital-analog transceiver front-end array according to an embodiment of the present invention.

[0022] Figure 2 This is a bottom view schematic diagram of the glass-based panel-level hybrid digital-analog transceiver front-end array according to an embodiment of the present invention.

[0023] Figure 3 This is a cross-sectional structural schematic diagram of the glass-based panel-level hybrid digital-analog transceiver front-end array according to an embodiment of the present invention.

[0024] Figure 4 This is a functional block diagram of a single radio frequency transceiver unit.

[0025] The reference numerals in the attached figures are explained as follows: 1-Panel-level glass substrate; 2-Glass antenna layer; 3-Glass functional layer; 4-Rewiring layer; 5-Dielectric layer; 6-Metal wiring layer; 7-Glass via; 8-Bonding area; 9-Upper surface pad; 10-Lower surface solder ball / pad; 11-RF transceiver unit; 12-Mixed-signal SoC; 13-Digital baseband processor; 14-High-speed data converter; 15-RF transceiver; 16-Receiver low-noise amplifier circuit; 17-Transmitter drive amplifier circuit; 18-Analog frequency conversion circuit; 19-Frequency source circuit; 20-Power amplifier and switching unit; 21-Power amplifier microwave integrated circuit; 22-Switching microwave integrated circuit; 23-Power management and clock distribution network; 24-Power management chip; 25-Clock distribution network; 26-Passive device network; 27-Panel-level antenna array; 28-Planar antenna unit; 29-Feed transmission line; 30-Power amplifier output transmission line; 31-Panel-level package. Detailed Implementation

[0026] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0027] like Figures 1-3As shown, the glass-based panel-level hybrid digital-analog transceiver front-end array provided by this invention has two square or rectangular panel-level glass substrates 1 as its core. It includes a glass antenna layer 2 and a glass functional layer 3. On the upper surfaces of the glass antenna layer 2 and the glass functional layer 3, multiple fine redistribution layers 4 (RDLs) are fabricated using photolithography and film deposition processes to achieve horizontal electrical interconnection of signals in the X and Y directions. Inside the glass antenna layer 2 and the glass functional layer 3, a large number of glass vias 7 (TGVs) are arrayed and fabricated using laser etching, thin film deposition, electroplating, and other processes to achieve vertical electrical interconnection of signals in the Z direction.

[0028] Several radio frequency transceiver units 11 are assembled in an array at designated positions on the upper surface of the glass panel 1. A mixed-signal SoC 12 is integrated onto the upper surface pad 9 of the glass functional layer 3 via flip-chip bonding, with a micro-bump spacing of less than 100 μm to accommodate high-frequency signal transmission and reduce parasitic inductance. A low-noise receiver amplifier circuit 16, a transmit drive amplifier circuit 17, an analog frequency converter circuit 18, and a frequency source circuit 19 are integrated onto the upper surface pad 9 of the glass functional layer 3 via wire bonding. A power amplifier microwave integrated circuit 21 and a switching microwave integrated circuit 22 are integrated onto the upper surface pad 9 of the glass functional layer 3 via wire bonding. A power management chip 24 is integrated onto the lower surface solder balls / pads 10 of the glass functional layer 3 via flip-chip bonding. The center-to-center spacing between adjacent radio frequency transceiver units is set according to the antenna element spacing.

[0029] In the gaps between the chip mounting areas and around them, planar antenna elements 28 are patterned using the redistribution layer 4 (RDL) on the upper surface of the glass antenna layer 2, forming a panel-level antenna array 27. Each planar antenna element 28 is connected to the RF port of the corresponding RF transceiver unit 11 via a carefully designed microstrip line or coplanar waveguide transmission line 29. The output of the power amplifier microwave integrated circuit 21 is connected to the antenna via a wider transmission line 30.

[0030] Figure 4 An internal functional block diagram of a typical RF transceiver unit 11 is shown. Its core is a mixed-signal SoC 12, which integrates a digital baseband processor 13 (including a DBF algorithm unit), a high-speed data converter 14, and an RF transceiver 15. It also includes a receive low-noise amplifier circuit 16, a transmit drive amplifier circuit 17, an analog frequency converter circuit 18, and a frequency source circuit 19. The RF transceiver 15 includes a phase-locked loop, a mixer, a filter, and a variable gain amplifier.

[0031] Brief description of preparation method: 1. Clean, drill (using laser or wet etching to form TGV), and metallize large-area glass panels. Then, using a process similar to semiconductor front-end processes, multiple thin-film deposition, photolithography, electroplating, and etching are used to construct multi-layer high-density RDLs. 2. Pattern the glass antenna layer (if an additional dielectric layer is required, deposit it first and then pattern it); 3. Integrate various flip-chips onto the glass functional layer using flip-chip bonding technology; 4. Integrate various wire-bonded chips onto the glass functional layer using wire bonding technology; 5. Achieve three-dimensional stacking of glass antenna layer and glass functional layer through laser bonding.

[0032] 6. Perform overall molding and encapsulation, and open windows in the antenna area to form the final panel-level product. The entire panel can be used as a whole, or it can be diced and divided into individual subarray-level modules as needed.

[0033] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A glass-based panel-level hybrid digital-analog transceiver front-end array, characterized in that, include: Panel-level glass substrate (1), several radio frequency transceiver units (11), power amplification and switching units (20), power management and clock distribution network (23), passive device network (26), panel-level antenna array (27), and panel-level package (31). The panel-level glass substrate (1) has a double-layer structure, including a glass antenna layer (2) and a glass functional layer (3). The glass antenna layer (2) and the glass functional layer (3) are evenly distributed with redistribution layers (4) for horizontal electrical interconnection and glass vias (7) for vertical electrical interconnection and auxiliary heat dissipation. A number of radio frequency transceiver units (11) are arranged in an array and integrated on the upper surface of the glass functional layer (3). Each radio frequency transceiver unit (11) integrates a mixed-signal SoC (12), a receiving low-noise amplifier circuit (16), a transmitting drive amplifier circuit (17), an analog frequency conversion circuit (18), and a frequency source circuit (19) to construct a complete mixed-signal radio frequency transceiver link. The power amplification and switching unit (2) 0) Integrated between the upper surface of the glass functional layer (3), the radio frequency transceiver unit (11), and the panel-level antenna array (27); the power management and clock distribution network (23) is arranged in the lower surface of the glass functional layer (3), the redistribution layer (4), and the glass via (7); the passive device network (26) is integrated and arranged through the redistribution layer (4) and the glass via (7) of the glass functional layer (3); the panel-level antenna array (27) is integrally fabricated on the upper surface of the glass antenna layer (2), and is directly fed through the redistribution layer (4) and the glass via (7) built into the glass antenna layer (2); the panel-level package (31) covers the outside of the overall structure and only exposes the radiating surface of the panel-level antenna array (27).

2. The glass-based panel-level hybrid digital-analog transceiver front-end array according to claim 1, characterized in that, The mixed-signal SoC (12) integrates a digital baseband processor (13), a high-speed data converter (14), and an RF transceiver (15). The digital baseband processor (13) has a built-in DBF digital beamforming algorithm unit for digital domain weighting and phase shifting of multi-channel transceiver signals.

3. The glass-based panel-level hybrid digital-analog transceiver front-end array according to claim 1, characterized in that, The minimum line width / spacing of the redistribution layer (4) is 2μm / 2μm or less, which meets the requirements of millimeter wave high frequency and high density integrated transmission.

4. The glass-based panel-level hybrid digital-analog transceiver front-end array according to claim 1, characterized in that, The radio frequency transceiver unit (11) is interconnected with the glass functional layer through microbumps with a spacing of less than 100 μm.

5. The glass-based panel-level hybrid digital-analog transceiver front-end array according to claim 1, characterized in that, The panel-level antenna array (27) operates in the frequency band of 30 GHz to 100 GHz.

6. The glass-based panel-level hybrid digital-analog transceiver front-end array according to claim 1, characterized in that, The inner wall of the glass via (7) is metallized to provide vertical signal interconnection and enhance heat dissipation.

7. The glass-based panel-level hybrid digital-analog transceiver front-end array according to claim 1, characterized in that, The mixed-signal SoC (12) is integrated on the upper surface pad (9) of the glass functional layer (3) by flip-chip bonding. The power amplifier microwave integrated circuit (21) and the switching microwave integrated circuit (22) are integrated on the upper surface pad (9) of the glass functional layer (3) by wire bonding. The power management chip (24) is integrated on the lower surface solder ball / pad (10) of the glass functional layer (3) by flip-chip bonding.

8. The glass-based panel-level hybrid digital-analog transceiver front-end array according to claim 1, characterized in that, The glass antenna layer (2) and the glass functional layer (3) are integrated in three dimensions by laser bonding process through the corresponding bonding area (8).

9. A method for preparing a glass-based panel-level hybrid digital-analog transceiver front-end array as described in any one of claims 1-8, characterized in that, include: Glass vias are formed and metallized on the glass antenna layer and glass functional layer; multiple high-density redistribution layers are fabricated on the surface of the glass antenna layer and glass functional layer; a planar antenna array pattern is fabricated on the surface of the glass antenna layer; the RF transceiver unit, power amplifier and switching unit, and power management are assembled to the designated positions on the glass functional layer; the three-dimensional stacking of the glass antenna layer and glass functional layer is achieved by laser bonding; panel-level molding encapsulation is performed to expose the antenna radiating surface.

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