Modular assembly method for data radio frequency front end equipment

Abstract

The application discloses a kind of modular assembly methods of data transmission radio frequency front-end equipment, and equipment is assembled relying on microfluidic physical architecture to execute assembly.Method includes: radio frequency component is placed into mainboard and constructs closed loop verification loop;Activate acoustic surface wave transducer array to generate acoustic radiation force, drive two-phase fluid material into microcavity structure to establish initial conductive interconnection;According to the impedance offset extracted by verification loop, use acoustic wave to drive phase change conductive alloy into blind end microchannel to form equivalent stub structure, offset parasitic susceptance to realize characteristic impedance matching;High-power radio frequency energy is injected to interconnection node, and local current crowding effect is generated to generate targeted joule heat at interface geometric mutation, trigger irreversible crosslinking phase change of thermoplastic insulating polymer matrix, and in-situ physical packaging is carried out to phase change conductive alloy.The application eliminates the thermal stress damage of high-temperature welding, and realizes the adaptive compensation of high-frequency impedance mismatch caused by mechanical assembly tolerance.

Description

Technical Field

[0001] This invention relates to the fields of electronic manufacturing and microwave radio frequency packaging technology, specifically a modular assembly method for a data transmission radio frequency front-end device. Background Technology

[0002] Data transmission radio frequency (RF) front-end equipment plays a crucial role in modern wireless communication, and the reliability of its interconnection and assembly process directly determines the overall physical transmission quality of RF signals. With the extension of communication frequency bands to higher frequencies and the increasing integration of RF devices, existing modular assembly processes have revealed significant limitations in the physical manufacturing stage.

[0003] Currently, the interconnection between RF components and motherboards mostly relies on surface mount technology or high-temperature soldering processes such as ball grid array packaging, or is assembled using rigid RF connectors. In the high-temperature reflow soldering process, the melting and cooling phase transition of solid metal solder will generate significant temperature gradient changes, which in turn will generate great thermal stress. The aforementioned thermal stress is very easy to be conducted into the RF components to be assembled, causing irreversible thermodynamic deformation or even physical damage to temperature-sensitive high-frequency RF components.

[0004] At the high-frequency electrical interconnect level, traditional interconnect methods based on solid metal solder or rigid pins constitute static open-loop physical connections. Limited by the etching precision of the motherboard and the conventional assembly tolerances of mechanical surface mount equipment, there is an objective micrometer-level physical misalignment between the pins of RF components and the motherboard pads during mating. Under high-frequency operating conditions, this physical assembly tolerance directly translates into non-negligible parasitic inductance and capacitance at the interconnect nodes, causing the microwave impedance of the interconnect interface to deviate significantly from the target characteristic impedance. After mechanical assembly or solder solidification, the conductive physical morphology of the interconnect nodes is permanently fixed, making in-situ physical morphology compensation based on actual high-frequency parasitic effects impossible during assembly. If impedance mismatch is discovered after assembly, external impedance matching components are typically added for post-assembly electrical compensation; this not only occupies limited wiring area on the motherboard and increases hardware manufacturing costs but also makes it difficult to maintain consistent yield rates for large-scale high-frequency interconnect assembly of data transmission RF front-end equipment. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a modular assembly method for data transmission radio frequency front-end equipment, which solves the problems of thermal stress damage to devices caused by traditional high-temperature welding processes, and high-frequency impedance mismatch caused by mechanical assembly tolerances, which cannot be compensated in situ.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a modular assembly method for a data transmission radio frequency front-end device, comprising: an assembly device interconnecting and assembling the radio frequency components to be assembled with a motherboard, and executing a modular assembly process based on a microfluidic physical architecture. The microfluidic physical architecture includes a motherboard, several blind-end microchannels, a piezoelectric ceramic surface acoustic wave transducer array, and a biphase fluid material. Metal pads inside the motherboard and metal pins outside the radio frequency components to be assembled form a semi-closed microcavity structure at their mating points; the microcavity structure serves as the interconnection node for main signal transmission. Blind-end microchannels are disposed on the sidewalls of the microcavity structure. The piezoelectric ceramic surface acoustic wave transducer array is embedded around the microcavity structure and the blind-end microchannels. The biphase fluid material consists of an inner layer of phase-change conductive alloy and an outer layer of thermoplastic insulating polymer matrix, serving as the filling medium for the interconnection nodes. The aforementioned modular assembly method achieves modular interconnection assembly through four interrelated physical processes: Step 1: Mechanical pre-locking and closed-loop verification circuit establishment: The assembly equipment places the RF components into the assembly slots of the motherboard and applies normal clamping force to complete mechanical pre-locking. A closed-loop verification circuit is constructed by contacting the preset test leads on the motherboard with external test probes. A low-power continuous wave test signal is injected into the interconnection node to establish a reflection parameter comparison benchmark. Step 2: Initial injection of liquid medium driven by acoustic waves: The piezoelectric ceramic surface acoustic wave transducer array is activated to generate a standing wave in the acoustic field. Under the action of the standing wave, the acoustic radiation force on the two-phase fluid material drives the two-phase fluid material to overcome the surface tension and capillary resistance of the microcavity structure and move in a directional manner. The acoustic radiation force acting on the leading edge of the two-phase fluid material follows the physical equation of acoustic radiation force in conventional fluid acoustics theory. The macroscopic propulsion direction and intensity of the acoustic radiation force are determined by the sign and absolute value of the acoustic contrast factor. During the initial physical and electrical connection establishment process of the phase change conductive alloy filling the air gap, the closed-loop verification circuit synchronously extracts the voltage reflection coefficient of the assembly interface. Its value follows the definition of voltage reflection coefficient in conventional microwave transmission theory, i.e., the difference between the equivalent complex impedance and the target characteristic impedance divided by the sum of the equivalent complex impedance and the target characteristic impedance. The third step involves fluid topology reconstruction and verification within the microchannel network: when parasitic susceptance caused by assembly tolerances leads to characteristic impedance mismatch, the assembly equipment calculates the in-situ compensation amount in reverse based on the impedance offset and uses acoustic pressure to drive the phase change conductive alloy into or out of the corresponding blind-end microchannel. The phase change conductive alloy constitutes an equivalent stub structure that alters the RF transmission characteristics within the blind-end microchannel. If the phase change conductive alloy is driven into a short-circuit type blind-end microchannel with a solid, sealed metal wall at the channel end, the target physical advancement length and the equivalent compensation susceptance follow the standard cotangent function mapping relationship of the short-circuit stub in microwave transmission theory. If the driving phase change conductive alloy enters the open-circuit blind-end microchannel that connects to the pre-set insulating air cavity inside the motherboard at the end of the channel, the target physical propulsion length and the equivalent compensation susceptance follow the standard tangent function mapping relationship of the open stub in microwave transmission theory.The phase-change conductive alloy dynamically alters the conductive physical topology of the interconnect nodes until the reactive components are completely canceled out, achieving characteristic impedance matching. The fourth step involves targeted locking of the material phase change and assembly morphology: a closed-loop verification circuit switches operating modes to inject high-power continuous-wave radio frequency energy into the interconnect nodes. At the micro-geometric abrupt change in the interface between the microcavity structure and the equivalent stub structure, the high-frequency current deviates from its uniform distribution, triggering a local current congestion effect. The increase in local current density generates targeted local Joule heating in the conductive interface region. The targeted local Joule heating power density follows the local Joule heating equation in electromagnetic field microwave transmission theory, meaning the local Joule heating power density is proportional to the square of the local current density amplitude and inversely proportional to the physical conductivity of the phase-change conductive alloy. The internally conducted heat causes the interface temperature to exceed the phase change temperature threshold of the thermoplastic insulating polymer matrix, triggering an irreversible molecular cross-linking reaction. The thermoplastic insulating polymer matrix transforms from a liquid phase into a rigid solid insulating medium, completing in-situ three-dimensional physical encapsulation.

[0007] Preferably, in the mechanical pre-locking and closed-loop verification circuit establishment step, the test lead has already formed physical electrical connection with the internal interconnection node during the motherboard wiring stage; the test probe integrates both an RF test port and a transducer drive port; the motherboard surface has a pre-set transducer excitation pad, which forms electrical connection with the piezoelectric ceramic surface acoustic wave transducer array through internal wiring; when the test probe contacts, the transducer drive port and the transducer excitation pad are correspondingly attached to transmit drive electrical signals, and the tail end of the RF test port of the test probe is connected to the signal generation source and the reflection parameter receiving device through a high-frequency coaxial cable to form the physical hardware link of the closed-loop verification circuit.

[0008] Preferably, the motherboard has a pre-installed liquid reservoir and connecting microchannels. The liquid reservoir stores the biphase fluid material in advance, and the connecting microchannels connect the liquid reservoir and the microcavity structure to provide a physical pathway for fluid injection. The phase change conductive alloy is a gallium indium tin alloy fluid that remains liquid at room temperature or a gallium-based fluid doped with nano-conductive particles. The thermoplastic insulating polymer matrix is ​​a thermosensitive cross-linked resin.

[0009] Preferably, in the material phase change and assembly morphology targeting and locking step, the specific power range of the high-power continuous wave radio frequency energy is configured to be 10W to 50W, and the duration of a single injection is configured to be 1ms to 10ms; the targeted local Joule heat diffuses to the outer surface of the phase change conductive alloy and conducts to the outer edge within milliseconds; during the solidification phase change process, the rigid solid insulating medium formed presses and fixes the phase change conductive alloy to the inner wall of the microcavity structure through the wrapping constraint force and interface bonding force.

[0010] Preferably, at least two blind-end microchannels are provided on the sidewall of the microcavity structure, and the planar arrangement configuration includes any one of the following: cross-shaped configuration, annular radial configuration, or multi-level bifurcation configuration, forming a multi-degree-of-freedom adjustable microchannel network; each blind-end microchannel is independently equipped with interdigitated electrodes for exciting acoustic standing waves on its sidewall, and the multi-level bifurcation configuration is that a main blind-end microchannel extends a set distance to derive at least two secondary blind-end microchannels.

[0011] Preferably, in the fluid topology reconstruction and verification step within the microchannel network, when the parasitic susceptance caused by mechanical assembly tolerance exceeds the upper limit of the compensation susceptance corresponding to the maximum filling length of a single blind-end microchannel, an extended matching process is executed: the closed-loop verification circuit decomposes the total target compensation susceptance into a set of sub-compensation susceptances of multiple parallel branches according to the allocation rules preset in the control program; the allocation rules are weighted allocation according to the maximum effective filling volume ratio of different blind-end microchannels, or equal allocation to symmetrical blind-end microchannels with the same physical structure; the allocated sub-compensation susceptance sets are mapped to the blind-end microchannels in different spatial orientations to independently calculate the target physical propulsion length, synchronously drive or sequentially drive the piezoelectric ceramic surface acoustic wave transducers in the corresponding orientations, and form a distributed radio frequency matching network composed of multiple equivalent stub structures connected in parallel at the interconnection node.

[0012] Preferably, in the mechanical pre-locking and closed-loop verification circuit establishment step, the normal clamping force is specifically set to a range of 0.5N to 2.5N, and the assembly equipment maintains the normal clamping force until the modular assembly process ends to prevent the microcavity structure from failing; the power of the low-power continuous wave test signal is strictly limited to between -20dBm and 0dBm.

[0013] Preferably, the phase change conductive alloy contains uniformly distributed high permeability nanoparticles with a mass fraction of 0.5% to 3%, constituting a modified two-phase fluid material; the high permeability nanoparticles are specifically made of nano-nickel powder or nano-iron powder.

[0014] Preferably, the doping of the high permeability nanoparticles alters the physical parameter regulation characteristics of the two-phase fluid material: during the initial injection step of the liquid medium driven by acoustic waves, the doping of the high permeability nanoparticles increases the overall equivalent density of the phase change conductive alloy, increases the density difference with the thermoplastic insulating polymer matrix, and increases the absolute value of the acoustic contrast factor to apply a greater acoustic radiation force to the phase change conductive alloy.

[0015] Preferably, when performing the material phase change and assembly morphology targeting and locking step, the doping of the high permeability nanoparticles increases the overall equivalent permeability of the phase change conductive alloy, thereby reducing the microwave skin depth of the phase change conductive alloy. This forces the high-frequency current to concentrate more towards the outer surface of the conductor at the location of the geometric abrupt change in cross-section, and improves the heat generation rate of targeted local Joule heating by compressing the effective conductive cross-sectional area of ​​the conductive interface.

[0016] The modular assembly method of this invention employs an assembly process combining in-situ fluid medium forming and radio frequency closed-loop verification. It utilizes acoustic standing waves to drive conductive fluid to construct a dynamic topological network within a microscopic space, transforming mechanical assembly tolerances into controllable high-frequency impedance compensation parameters. Simultaneously, it leverages the local current congestion effect of high-frequency microwaves to achieve targeted thermal curing, eliminating welding thermal stress damage associated with traditional physical welding. This enables adaptive matching and long-term stable physical packaging of the interconnect interface for data transmission radio frequency front-end devices.

[0017] This invention provides a modular assembly method for a data transmission radio frequency front-end device. It has the following advantages: 1. This invention uses a phase change conductive alloy that remains liquid at room temperature as the interconnecting medium. The acoustic radiation force generated by a piezoelectric ceramic surface acoustic wave transducer array drives the phase change conductive alloy to perform physical connections, replacing the traditional high-temperature reflow soldering process. These technical features eliminate the thermal stress damage to internal RF components of the data transmission RF front-end equipment caused by the high-temperature soldering process, and reduce the loss rate of RF devices during assembly.

[0018] 2. This invention incorporates blind-end microchannels on the sidewalls of the microcavity structure, combined with a closed-loop verification circuit to perform fluid topology reconstruction. When mechanical assembly tolerances cause high-frequency impedance mismatch in interconnect nodes, the assembly equipment dynamically adjusts the physical filling length of the phase-change conductive alloy within the blind-end microchannels via closed-loop feedback, generating an equivalent stub structure in situ at the interconnect node to offset parasitic reactive components. This adaptive compensation mechanism absorbs the high-frequency parasitic effects caused by mechanical assembly tolerances, achieving characteristic impedance conjugate matching of the interconnect interface without adding an external independent matching circuit.

[0019] 3. This invention utilizes the local current congestion effect induced by high-power continuous wave radio frequency energy at microscopic geometric abrupt changes to target and generate local Joule heating to trigger the cross-linking phase transition of the thermoplastic insulating polymer matrix. This localized targeted heating mechanism multiplexes the radio frequency signal as a curing heat source, providing the energy required for in-situ curing only in the conductive interface region, avoiding the heat conduction risks caused by global heating. Simultaneously, the rigid solid insulating medium formed by the curing of the thermoplastic insulating polymer matrix provides three-dimensional physical encapsulation of the phase transition conductive alloy in a target impedance-matched state, ensuring the long-term physical stability of the interconnect node's radio frequency performance. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the overall process flow of the present invention. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see the appendix Figure 1 This invention provides a modular assembly method for a data transmission radio frequency front-end device.

[0023] The data transmission RF front-end device assembly process of the present invention relies on a specific microfluidic physical architecture. The motherboard surface has assembly slots to accommodate the internal RF components of the data transmission RF front-end device. The metal pads inside the motherboard and the metal pins outside the RF components form a semi-closed microcavity structure at the docking position. The microcavity structure serves as the interconnection node for the main signal transmission. In order to record the technical terms summarized in the claims in the specification and provide sufficient support, the specific three-dimensional form of the microcavity structure described herein includes, but is not limited to, cylindrical slots, polygonal blind holes, or stepped groove structures. All of the above-mentioned lower forms can provide fluid medium accommodating space to realize high-frequency interconnection.

[0024] On the sidewall of the microcavity structure, several blind-ended microchannels extend outward along the horizontal or vertical direction of the motherboard. The topological arrangement of the blind-ended microchannels includes orthogonal cross shape, annular radial shape, or L-shaped bend. The blind-ended microchannels are divided into two types according to their terminal structure: the first type is an open-circuit blind-ended microchannel, the end of which is connected to a pre-set insulating air cavity inside the motherboard to form an open-circuit matching stub; the second type is a short-circuit blind-ended microchannel, the end of which is a solid sealed metal wall to form a short-circuit matching stub. The two types of blind-ended microchannels are arranged alternately along the circumference of the main microcavity structure. At least one blind-ended microchannel of each type is provided, corresponding to the susceptance compensation requirements of different polarities. The above-mentioned specific geometric structure combination constitutes the microchannel network described in the claims. The purpose of establishing the microchannel network is to provide controllable physical volume changes in different spatial dimensions, and to adjust the equivalent microwave impedance of the interconnect interface by changing the conductive geometry at the interconnect nodes.

[0025] The motherboard contains embedded driving components around the microcavity structure and blind-end microchannels. Specifically, these driving components are piezoelectric ceramic surface acoustic wave (SAW) transducer arrays. The SAW transducer array excites standing waves of a specific frequency on the piezoelectric substrate using interdigitated electrodes. For the electrode photolithography fabrication process and RF excitation driving circuit design of the SAW transducer, those skilled in the art can refer to existing microelectromechanical systems (MEMS) manufacturing technologies. The basic physical structure and transduction principle of the SAW transducer array are well-known technologies in this field and will not be elaborated upon here.

[0026] The motherboard also has a pre-installed liquid reservoir and connecting microchannels. The liquid reservoir is used to pre-store two-phase fluid material, and the connecting microchannels connect the liquid reservoir and the main microcavity structure respectively, serving as a physical path for fluid injection. The liquid reservoir can be pre-sealed and filled with two-phase fluid material during the motherboard manufacturing stage, or it can be temporarily injected at the assembly site through the injection interface.

[0027] The assembly process of this invention uses a two-phase fluid material as the filling medium.

[0028] In the specific embodiments described in the specification, the aforementioned biphase fluid material is specifically composed of two parts: an inner phase change conductive alloy and an outer thermoplastic insulating polymer matrix. The phase change conductive alloy is specifically implemented as a gallium indium tin alloy fluid that remains liquid at room temperature or a gallium-based fluid doped with nano-conductive particles. The thermoplastic insulating polymer matrix is ​​specifically implemented as a thermosensitive cross-linked resin. The thermosensitive cross-linked resin has the physical property of irreversibly transforming from a liquid phase to a rigid solid medium at a specific temperature threshold.

[0029] The assembly equipment relies on the aforementioned physical architecture to execute a modular assembly process that includes four macroscopic stages.

[0030] In step S100, the mechanical pre-locking and closed-loop verification circuit are established. The assembly equipment uses mechanical positioning components to place the RF component into the assembly slot of the motherboard and applies normal clamping force to complete the mechanical pre-locking. Due to the objective mechanical assembly tolerance between different components, an air gap is still left inside the microcavity structure after pre-locking. The RF component pins and the motherboard pads have not yet established a physical conductive path. In order to implement in-situ monitoring, the assembly equipment contacts the leads at both ends of the interconnect node through external test probes and connects to the signal source. This physical link is used to build a closed-loop verification circuit. The closed-loop verification circuit injects a low-power continuous wave test signal into the interconnect node to establish a real-time reading channel for reflection parameters.

[0031] In step S200, the liquid medium is initially injected under acoustic wave drive. The assembly equipment activates the surface acoustic wave transducer array on the motherboard. Under the direct action of the acoustic radiation force generated by the acoustic field standing wave, the two-phase fluid material overcomes the capillary resistance and surface tension of the inner wall of the microcavity structure and is directionally pumped into the interconnect node. The phase change conductive alloy fills the air gap under the drive of acoustic radiation force, establishing the initial physical and electrical connection. The closed-loop verification circuit obtains the voltage reflection coefficient and voltage standing wave ratio parameters of the interconnect interface in real time. The read radio frequency parameters are used as process monitoring indicators to determine whether mechanical tolerances cause high-frequency parasitic effects.

[0032] Step S300: Fluid topology reconstruction and verification within the microchannel network. After the phase change conductive alloy stops being injected into the main channel, if the monitoring indicators extracted by the closed-loop verification loop fail to reach the preset impedance qualification threshold, it indicates that the mechanical assembly tolerances left over from the previous stage have caused a non-negligible high-frequency parasitic inductance or parasitic capacitance effect at the interconnection nodes. After determining that the parameters exceed the standard, the assembly equipment triggers the topology reconstruction process. Based on the impedance offset extracted by the closed-loop verification loop, the assembly equipment calculates in reverse the in-situ compensation amount required to achieve characteristic impedance matching. Subsequently, the assembly equipment adjusts the excitation state of the surface acoustic wave transducer on the corresponding blind-end microchannel side, and uses acoustic wave pressure to dynamically push and pull a specific volume of phase change conductive alloy to the calculated physical depth. The closed-loop verification loop continuously monitors the continuous physical offset process of the equivalent microwave topology. When the reflection parameters approach the minimum value range, the assembly equipment cuts off the excitation of the surface acoustic wave transducer.

[0033] In step S400, after the material phase change and assembly morphology are targeted and locked, and the topology reconstruction parameters are confirmed to be qualified, the closed-loop verification circuit switches to the working mode. High-power continuous wave radio frequency energy is injected into the interconnect node through the same set of test probes. The high-power radio frequency energy induces a local current congestion effect at the micro-geometric abrupt change at the interface between the microcavity structure and the blind-end microchannel. Local Joule heating is generated in the conductive interface region that achieves ideal high-frequency matching. The heat accumulated inside is conducted from the central conductor to the outer edge. When the interface temperature exceeds the phase change temperature threshold of the outer thermoplastic insulating polymer matrix, the outer thermoplastic insulating polymer undergoes an irreversible molecular cross-linking reaction, completely transforming from the initial liquid phase structure into a rigid solid insulating medium. The rigid encapsulation constraint and interface bonding force formed during the curing process encapsulate the phase change conductive alloy in the ideal high-frequency matching morphology in situ in three-dimensional physical packaging, thus completing the long-term fixation and closed-loop assembly process of the high-frequency interconnect interface of the data transmission radio frequency front-end equipment.

[0034] The modular assembly process of the data transmission radio frequency front-end equipment consists of a series of specific physical operation steps. The assembly equipment executes step S100 according to the set program logic. Step S100 specifically covers the physical level position fixing and the electrical level test link connection process. In order to clarify the technical details and support the superior concept in the claims, step S100 is further divided into sub-steps S101 to S104 in the specific implementation.

[0035] Step S101 involves the physical alignment of the assembly interface. The assembly equipment includes a pickup component that picks up the RF component to be assembled and moves it directly above the motherboard assembly slot. The assembly equipment uses an optical alignment component to identify the position coordinates of the motherboard pads and the RF component pins, and drives the robotic arm to complete the spatial alignment of the motherboard pads and the RF component pins. For the image recognition algorithm of the optical alignment component and the spatial coordinate transformation logic of the robotic arm, those skilled in the art can refer to existing surface mount equipment for configuration. The aforementioned image recognition and motion control logic are well-known technologies in the field and will not be elaborated further in this document.

[0036] In step S102, a normal clamping force is applied to complete the mechanical pre-locking. After completing the spatial alignment process, the assembly equipment controls the robotic arm to descend vertically, allowing the pins of the RF component to enter the assembly slots on the motherboard. The assembly equipment applies a preset normal clamping force to the RF component and maintains the aforementioned normal clamping force until the assembly process ends. The specific value range of the normal clamping force is set to 0.5N to 2.5N. The purpose is to ensure that the RF component will not undergo macroscopic displacement in the subsequent acoustic wave driving process, thereby causing the microcavity structure to fail. Under the action of the normal clamping force, the metal pads inside the motherboard and the metal pins outside the RF component are spliced ​​and closed at the docking position to form a semi-closed microcavity structure. Due to the limitations of metal processing precision and assembly tolerance, an air gap is left inside the microcavity structure in the pre-locked state. The width of the air gap is distributed between 20μm and 150μm. At this time, the RF component pins and the motherboard pads have not yet established a physical conductive path.

[0037] Step S103: Construct a closed-loop verification circuit. Assemble the device to drive the external test probe to move and contact the preset test leads on the motherboard. The test leads correspond to the signal path end and ground reference end of the interconnect node, respectively. The aforementioned test leads have formed physical electrical connection with the internal interconnect nodes during the motherboard wiring stage. The test probe described in the claims is, in a specific embodiment, a coplanar waveguide probe or a coaxial RF probe. The probe integrates an RF test port and a transducer drive port. The motherboard surface has a pre-set transducer excitation pad, which forms electrical connection with the pre-embedded surface acoustic wave transducer array through internal wiring. When the test probe is pressed down to make contact, the transducer drive port and the transducer excitation pad are correspondingly attached to transmit drive electrical signals to the pre-embedded surface acoustic wave transducer array. The tail end of the RF test port of the test probe is connected to the signal generator and the reflection parameter receiving device through a high-frequency coaxial cable. The test probe, the high-frequency coaxial cable, the signal generator, and the reflection parameter receiving device together constitute the physical hardware link of the closed-loop verification circuit.

[0038] Step S104: Inject test signal and establish initial reference. The signal generator of the closed-loop verification circuit injects a low-power continuous wave test signal into the interconnect node through the test probe. In order to prevent the energy of the test signal from being converted into excessive Joule heat at the interconnect node and prematurely triggering the curing phase transition of the thermoplastic insulating polymer matrix in subsequent processes, the power of the continuous wave test signal is strictly limited to between -20dBm and 0dBm. The reflection parameter receiving device of the closed-loop verification circuit collects the incident voltage wave amplitude and the reflected voltage wave amplitude at the assembly interface in real time. Based on the collected voltage wave amplitude, the closed-loop verification circuit extracts the initial voltage reflection coefficient complex number of the interconnect node. According to conventional microwave transmission theory, the value of the initial voltage reflection coefficient complex number is the ratio of the complex amplitude of the reflected voltage wave at the interconnect node to the complex amplitude of the incident voltage wave.

[0039] Currently, the medium inside the interconnect node in the process is air, and the assembly interface exhibits an impedance mismatch. The calculated voltage reflection coefficient magnitude is at a high level. The closed-loop verification circuit uses the extracted initial voltage reflection coefficient as the comparison benchmark data for subsequent fluid injection and topology reconstruction processes. The establishment of the closed-loop verification circuit provides a continuous quantitative monitoring channel for the assembly equipment to sense the physical changes in the microwave impedance of the interconnect node in the subsequent production process.

[0040] After completing the physical pre-locking and closed-loop verification circuit establishment processes, the assembly equipment executes step S200. Step S200 utilizes acoustic waves to drive the dielectric material to complete the initial physical and electrical filling. Step S200 is divided into sub-steps S201 to S204.

[0041] Step S201: Activate the acoustic standing wave field and generate acoustic radiation force. ρm represents the physical density of the inner phase change composite alloy; cm represents the propagation speed of the acoustic wave within the inner phase change composite alloy. The surface acoustic wave transducer array converts the high-frequency AC excitation signal into an acoustic standing wave propagating within the motherboard. The acoustic standing wave generates acoustic radiation force in the region surrounding the interconnect nodes. The acoustic radiation force acts on the leading edge of the two-phase fluid material. Follows the following physical equations: In the formula, This represents the sound pressure amplitude of the standing wave in the local sound field inside the interconnected node; This represents the equivalent spherical radius of the propulsion wavefront of a two-phase fluid material; This indicates the physical density of the outer thermoplastic insulating polymer matrix; This indicates the speed at which sound waves propagate through the outer thermoplastic insulating polymer matrix; This indicates the physical density of the inner phase transformation composite alloy. This indicates the propagation speed of sound waves within the inner phase change composite alloy. The acoustic contrast factor represents the direction, magnitude, and intensity of the acoustic radiation force. The sign and absolute value of the acoustic contrast factor determine the macroscopic propulsion direction and magnitude of the acoustic radiation force. For the design of the high-frequency AC excitation signal generation circuit and the implementation of piezoelectric ceramic electroacoustic conversion, those skilled in the art can refer to existing microelectromechanical acoustic drive devices for configuration. The aforementioned piezoelectric transduction principle is well-known in the field and will not be elaborated further here.

[0042] Step S202: Fluid medium is injected directionally to overcome resistance. The motherboard has a reservoir for containing two-phase fluid material. The reservoir is connected to the microcavity structure through a connecting pipe. Under the continuous action of acoustic radiation force, the two-phase fluid material overcomes the surface tension and capillary resistance of the inner wall of the microcavity structure and moves along the aforementioned connecting pipe into the interconnection node for main signal transmission. In a specific embodiment, the medium injection action is manifested as the directional viscous flow physical behavior of the inner phase change conductive alloy and the outer thermoplastic insulating polymer matrix under the action of acoustic pressure gradient.

[0043] Step S203: Establish initial physical electrical connection. As the biphase fluid material continues to advance into the interconnect node, the liquid phase change conductive alloy in the inner layer gradually fills the air gap between the motherboard pads and the RF component pins inside the data transmission RF front-end device. The physical extension and contact of the phase change conductive alloy in space establishes an initial physical electrical path between the motherboard pads and the RF component pins.

[0044] Step S204, Closed-loop parameter extraction and injection control: During the fluid injection process, the closed-loop verification loop constructed in the previous step maintains a real-time online monitoring state. Based on the amplitude of the radio frequency test signal read by the test probe, the closed-loop verification loop calculates the complex voltage reflection coefficient of the interconnect interface. According to conventional microwave transmission theory, the complex voltage reflection coefficient is the difference between the equivalent complex impedance and the target characteristic impedance of the current assembly interface due to incomplete filling of the medium and mechanical tolerances, divided by the sum of the equivalent complex impedance and the target characteristic impedance of the current assembly interface. The closed-loop verification loop simultaneously calculates the scalar form of the voltage standing wave ratio. According to the basic microwave formula, the voltage standing wave ratio is equal to a factor equal to the magnitude of the voltage reflection coefficient plus a factor equal to the magnitude of the voltage reflection coefficient minus a factor equal to a factor equal to the magnitude of the voltage reflection coefficient.

[0045] The continuous change in voltage standing wave ratio (VSWR) objectively reflects the actual impact of the liquid medium filling progress on the high-frequency microwave impedance of the interconnect node. The assembly equipment control program has a pre-set basic injection time threshold, which is pre-set based on the total volume of the main microcavity and the calibrated average injection flow rate. This ensures that the phase change conductive alloy completely fills the main microcavity after injection and reserves adjustment margin for subsequent topology reconstruction. When the surface acoustic wave transducer array works continuously to reach the set basic injection time threshold, the assembly equipment pauses the high-frequency AC excitation signal of the surface acoustic wave transducer array and records the VSWR data output by the closed-loop verification circuit at the current moment. The recorded VSWR data will serve as the direct basis for starting the subsequent topology reconstruction process.

[0046] After the assembly equipment completes the initial injection process, it executes step S300. Step S300 uses blind-end microchannels to change the spatial distribution of the conductive medium, thereby eliminating microwave impedance mismatch caused by mechanical assembly tolerances from a physical perspective. Step S300 is divided into sub-steps S301 to S304.

[0047] Step S301: Extract equivalent admittance and calculate compensation parameters. The closed-loop verification circuit reads the voltage standing wave ratio (VSWR) data. When the extracted VSWR value is greater than the preset impedance qualification threshold, it indicates that the physical assembly tolerance inside the microcavity structure has caused parasitic inductance or parasitic capacitance effects. The closed-loop verification circuit converts the equivalent complex impedance presented at the current assembly interface into equivalent load admittance. Mathematically, the equivalent load admittance is separated into real conductance and imaginary parasitic susceptance. In order to achieve high-frequency characteristic impedance matching of interconnect nodes, the assembly equipment needs to introduce equivalent compensation susceptance in situ at the interconnect nodes. The value of the equivalent compensation susceptance must be equal to the magnitude of the imaginary parasitic susceptance and opposite in polarity, so as to achieve complete cancellation of reactive components in the physical circuit.

[0048] Step S302: Mapping the physical propulsion length. Based on the principle of microwave distributed parameters, the assembly equipment maps the required equivalent compensation susceptance to the specific physical propulsion length inside the blind-end microchannel. During the motherboard manufacturing stage, the end structure of the blind-end microchannel is pre-designed into two terminal physical forms.

[0049] If the physical end of the blind-end microchannel is a solid sealed wall, the blind-end microchannel constitutes an equivalent terminal short-circuit structure. According to conventional microwave transmission theory, the target physical advance length required for the phase change conductive alloy to enter the blind-end microchannel follows the standard cotangent function mapping relationship of the short-circuit stub with respect to the equivalent compensation susceptance, the characteristic admittance of the interconnect node, and the phase constant of the radio frequency signal.

[0050] If the physical end of the blind-end microchannel is connected to the pre-reserved insulating air cavity inside the motherboard, the blind-end microchannel constitutes an equivalent open-circuit terminal structure. According to conventional microwave transmission theory, the target physical advance length required for the phase change conductive alloy to enter the blind-end microchannel follows the standard tangent function mapping relationship of the open-circuit stub with respect to the equivalent compensation susceptance, the characteristic admittance of the interconnect node, and the phase constant of the radio frequency signal.

[0051] Step S303, Targeted Acoustic Wave Driving and In-situ Forming: Based on the calculated physical propulsion length, the assembly equipment selectively activates the surface acoustic wave transducer on the side of the corresponding blind-end microchannel. By controlling the phase of the excitation electrical signal and the emission duration of the surface acoustic wave transducer, the assembly equipment uses the acoustic radiation force generated by the target to push the liquid phase change conductive alloy into the selected blind-end microchannel, or to extract the phase change conductive alloy that has entered the blind-end microchannel. After the phase change conductive alloy fills a specific length inside the blind-end microchannel, it forms an equivalent stub structure that changes the radio frequency transmission characteristics at the physical level. The equivalent stub structure acts as a parallel branch, directly compensating for the parasitic effects on the main signal path of the interconnected node.

[0052] Step S304, Dynamic Verification and Topology Locking: During the targeted acoustic wave driven propulsion process, the closed-loop verification loop maintains continuous data acquisition. The closed-loop verification loop continuously monitors the voltage reflection coefficient of the interconnect interface. As the physical propulsion length of the phase change conductive alloy gradually approaches the target value, the parasitic reactive components of the interconnect nodes are gradually canceled out, and the magnitude of the voltage reflection coefficient shows a continuous downward trend. When the closed-loop verification loop detects that the magnitude of the voltage reflection coefficient has dropped to the preset minimum value range, it indicates that the high-frequency impedance of the interconnect interface has reached the characteristic impedance matching state. The assembly equipment cuts off the excitation electrical signal of the surface acoustic wave transducer. At this time, relying on the surface tension of the inner wall of the blind end microchannel and the capillary resistance inside the microcavity structure, the two-phase fluid material stops flowing. The phase change conductive alloy temporarily maintains the current microscopic physical topology before the subsequent thermosetting process.

[0053] After confirming that the fluid topology reconstruction within the microchannel network has reached the characteristic impedance matching state, the assembly equipment executes step S400.

[0054] Step S400 utilizes the local thermal effect induced by high-power microwave energy to trigger the curing of the dielectric material, thereby achieving permanent physical encapsulation of the high-frequency interconnect interface.

[0055] Step S400 is divided into sub-steps S401 to S404.

[0056] Step S401: Switch the signal output mode. The closed-loop verification loop controls the signal generator to change its operating state. The closed-loop verification loop stops injecting low-power test signals into the interconnect node and instead injects high-power continuous wave radio frequency signals into the interconnect node. The specific power range of the high-power continuous wave radio frequency signal is configured to be 10W to 50W, and the duration of a single injection is configured to be 1ms to 10ms. The aforementioned power and time parameters are pre-calibrated based on the latent heat of phase change of the thermoplastic insulating polymer matrix, the thermal conductivity of the phase change conductive alloy, and the simulation results of the local thermal field distribution. The purpose of limiting the aforementioned parameter range is to ensure that the injected electromagnetic energy is sufficient to trigger the local thermal effect, while avoiding the conduction of high-energy radio frequency energy into the radio frequency component to be assembled, which would cause thermal damage to the device.

[0057] Step S402 triggers local current congestion and targeted heat generation. A high-power continuous wave radio frequency signal is transmitted along the physical link of the closed-loop verification circuit to the interconnect node. At this point, the phase-change conductive alloy inside the interconnect node has formed a complete topology of the equivalent stub structure filled in the main path and the blind-end microchannel. A geometric cross-section abrupt change exists at the interface between the main microcavity structure and the equivalent stub structure formed by the filling in the blind-end microchannel. According to microwave transmission theory, when the high-frequency current flows through the aforementioned geometric cross-section abrupt change location, it will deviate from a uniform distribution state, generating a local current congestion effect at the interface edge. This local current congestion effect leads to an increase in the local current density in a specific region of the interface. This increase in local current density targets and generates highly concentrated local Joule heating at the interface. The power density of the targeted local Joule heating is... Follows the following physical equations: In the formula, This represents the local Joule heat power density generated per unit volume within a specific micro-geometric abrupt region of an interconnected node. This represents the magnitude of the local current density at the location where current congestion occurs in the interconnect node; This indicates the physical conductivity of the inner phase change conductive alloy material itself.

[0058] Step S403: Polymer matrix phase change and structure locking. The phase change conductive alloy has excellent thermal conductivity. The local Joule heat generated by specific micro-geometric abrupt change regions can rapidly diffuse to the entire outer surface of the phase change conductive alloy within milliseconds, and be conducted from the inside to the outside edge. This causes the interface temperature of the thermoplastic insulating polymer matrix around the phase change conductive alloy to rise. When the interface temperature exceeds the phase change temperature threshold of the outer thermoplastic insulating polymer matrix, the molecular structure of the outer thermoplastic insulating polymer matrix undergoes an irreversible cross-linking reaction. The specific implementation parameters of the phase change temperature threshold are set between 80°C and 120°C. This temperature range is higher than the normal operating environment temperature of the device and lower than the device temperature resistance threshold of the RF component, taking into account both curing reliability and device safety. The outer thermoplastic insulating polymer matrix transforms from the initial liquid phase structure into a rigid solid insulating medium. During the curing phase change process, the formed rigid solid insulating medium presses and fixes the phase change conductive alloy to the inner wall of the microcavity structure through the encapsulation constraint force and interface bonding force, thus performing in-situ three-dimensional physical encapsulation of the phase change conductive alloy in the target matching form. For the molecular crosslinking reaction mechanism and formulation control of thermoplastic insulating polymer matrix, those skilled in the art can refer to existing polymer polymerization processes for formulation. The crosslinking reaction and curing mechanism are well known technologies in this field and will not be elaborated here.

[0059] Step S404: Release the closed-loop verification circuit and complete the assembly. After the assembly equipment reaches the set upper limit for the duration, it cuts off the output of the high-power continuous wave radio frequency signal. The assembly equipment controls the external test probe to rise and detach from the test lead on the motherboard, releasing the physical electrical connection of the closed-loop verification circuit. The assembly equipment removes the normal clamping force applied to the radio frequency component and resets the pickup component of the assembly equipment. After curing, the remaining biphase fluid material in the connecting microchannel can be sucked out by negative pressure or retained as a spare medium for subsequent rework processes. The modular interconnection assembly process of the radio frequency component and the motherboard is completed. The interconnection nodes locked by the targeted thermal effect have stable high-frequency microwave impedance consistency, the interconnection interface has no welding thermal stress, and the rigid solid insulating medium can resist mechanical vibration and thermal cycling stress in the subsequent application environment.

[0060] To accommodate the assembly requirements of different models of data transmission RF front-end devices, the blind-end microchannels reserved inside the motherboard have various physical deformation implementations. These different configurations of blind-end microchannels together constitute a multi-degree-of-freedom adjustable microchannel network. The planar arrangement configurations of the blind-end microchannels include a cross-shaped configuration, a ring-radial configuration, and a multi-level bifurcated configuration. The cross-shaped configuration is characterized by four blind-end microchannels extending outward at a 90-degree orthogonal angle from the main microcavity structure as the center. The ring-radial configuration is characterized by six or eight blind-end microchannels along the main microcavity structure. The circumferential sidewalls are radially distributed at equal angles. The multi-level bifurcated configuration is characterized by a main blind-end microchannel extending a set distance and then deriving at least two secondary blind-end microchannels. The ends of all secondary blind-end microchannels are set as open-circuit or short-circuit terminal structures. This configuration can achieve large-range coarse adjustment of susceptance through the main channel and small-range precise fine adjustment through the secondary channels, taking into account both compensation range and adjustment accuracy. The multiple blind-end microchannels provide a multi-dimensional medium-accommodating volume in physical space, serving as the physical basis for the subsequent in-situ generation of combined stub structures.

[0061] The spatial arrangement of the surface acoustic wave transducer array embedded inside the motherboard corresponds physically to the planar arrangement of the blind-end microchannels. Each blind-end microchannel has an independently configured interdigitated electrode on its sidewall to excite standing waves in the acoustic field. For the photolithography etching process and corresponding interdigitated electrode wiring rules of microchannels with different arrangements, those skilled in the art can refer to existing multilayer printed circuit board manufacturing specifications. The multilayer microchannel solid molding and internal electrode wiring processes are well-known technologies in this field and will not be elaborated upon here.

[0062] When the assembly equipment performs fluid topology reconstruction using the aforementioned modified implementation method, it executes an extended matching process. The extended matching process is an optional extended implementation method of the fluid topology reconstruction in step S300, corresponding to sub-steps S305 to S307.

[0063] Step S305: Multidimensional equivalent parameter decomposition. The closed-loop verification circuit reads the complex impedance offset of the interconnect interface. When the parasitic susceptance caused by mechanical assembly tolerance exceeds the upper limit of the compensation susceptance corresponding to the maximum filling length of a single blind-end microchannel, the single parallel equivalent stub structure cannot completely cancel the reactive component. The assembly equipment calculates the total target compensation susceptance in reverse based on the complex impedance offset. The closed-loop verification circuit decomposes the total target compensation susceptance into a set of sub-compensation susceptances of multiple parallel branches according to the allocation rules preset in the control program. The allocation rules preset in the control program are: weighted allocation according to the maximum effective filling volume ratio of different blind-end microchannels, or equal allocation to symmetrical blind-end microchannels with the same physical structure. The sum of the algebraic values ​​of all sub-compensation susceptances is equal to the total target compensation susceptance.

[0064] Step S306: Mapping the physical lengths of multiple branches. Based on microwave network parameter theory, the assembly equipment maps the allocated sub-compensation susceptance to blind-end microchannels in different spatial orientations. The assembly equipment independently calculates the target physical advance length required for each blind-end microchannel participating in impedance compensation. According to conventional microwave transmission theory, the sub-compensation susceptance value allocated to a specific blind-end microchannel, the characteristic admittance of a specific blind-end microchannel, and the target physical advance length of the phase change conductive alloy entering a specific blind-end microchannel follow the standard trigonometric function mapping relationship of microwave short-circuit stub or open-circuit stub. The total susceptance compensation is distributed to multiple spatial dimensions for parallel compensation, which relaxes the unidirectional adjustment accuracy requirements of the microfluidic injection length at the physical structure level.

[0065] Step S307: Multi-directional collaborative driving and in-situ molding. The assembly equipment can select synchronous driving or time-sharing driving mode according to compensation requirements. The blind-end microchannels with symmetrical orientations adopt synchronous driving to balance the fluid pressure in the main microcavity. The blind-end microchannels with asymmetrical orientations adopt time-sharing sequential driving to avoid mutual interference of fluid flow. The acoustic radiation force in different spatial orientations pushes the liquid phase change conductive alloy inside the main microcavity structure into the corresponding blind-end microchannels. The phase change conductive alloy advances synchronously in each blind-end microchannel and reaches the corresponding target physical advancement length. At the interconnection node, a distributed radio frequency matching network composed of multiple equivalent stub structures connected in parallel is formed. The closed-loop verification circuit continuously monitors the voltage reflection coefficient of the interconnection interface until the high-frequency impedance of the interconnection interface reaches the characteristic impedance matching state. The assembly equipment cuts off the excitation signal of the surface acoustic wave transducer in all directions. The multi-branch micro-physical topology in the target impedance matching state enters the subsequent targeted thermal effect locking process.

[0066] To adapt to different assembly environments and optimize the assembly process of data transmission RF front-end equipment, a modified two-phase fluid material is constructed by uniformly distributing high-permeability nanoparticles of a specific mass fraction within the phase change conductive alloy. This material is a modified implementation of the basic two-phase fluid material, retaining the two-phase core structure of a conductive alloy core and a polymer matrix shell. The specific materials for the high-permeability nanoparticles include nano-nickel powder or nano-iron powder, with the mass fraction of high-permeability nanoparticles ranging from 0.5% to 3%. This mass fraction range ensures that the conductivity of the phase change conductive alloy does not significantly decrease while simultaneously improving acoustic driving performance and targeted heat generation efficiency. For the surface anti-oxidation treatment process of the nanoparticles and the ultrasonic dispersion and mixing process of the fluid material, those skilled in the art can refer to existing nanofluid preparation specifications for implementation. The surface treatment of nanoparticles and the fluid dispersion and mixing process are well-known technologies in this field and will not be elaborated upon here.

[0067] When using modified two-phase fluid materials to perform the original modular assembly process in the assembly equipment, the following corresponding parameter control sub-steps need to be performed in the acoustic injection process and the target locking process respectively.

[0068] Step S205, Acoustic Contrast Factor Adjustment: During the acoustic wave-driven fluid injection process, the high-permeability nanoparticles doped with the assembly equipment increase the overall equivalent density of the doped phase change conductive alloy. According to conventional fluid acoustics theory, the increased density difference between the altered equivalent density and the outer thermoplastic insulating polymer matrix leads to an increase in the absolute value of the acoustic contrast factor. This directly alters the acoustic characteristics of the modified two-phase fluid material within the microcavity structure. The change in the acoustic contrast factor value allows the assembly equipment to apply a greater acoustic radiation force to the phase change conductive alloy under the same surface acoustic wave excitation power output. The increased acoustic radiation force enhances the dielectric material's ability to overcome the capillary resistance of the microchannel at the blind end of the motherboard, thus relaxing the lower limit requirement for the output power of the acoustic transducer inside the assembly equipment.

[0069] Step S405, microwave skin depth control; during the targeted thermal effect locking process, the assembly equipment injects a high-power continuous wave radio frequency signal into the interconnect node; the doped high-permeability nanoparticles improve the overall equivalent permeability of the doped phase change conductive alloy; according to the electromagnetic field microwave transmission theory, there is a skin effect when high-frequency alternating current is transmitted inside the conductor; since the skin depth of the high-frequency radio frequency signal is inversely proportional to the square root of the conductor's equivalent permeability, the doping modification significantly reduces the microwave skin depth of the phase change conductive alloy.

[0070] The reduction in microwave skin depth forces high-frequency current to concentrate more towards the outer surface of the conductor at locations of abrupt changes in the geometric cross-section within the interconnect node. This concentration of high-frequency current compresses the effective conductive cross-sectional area of ​​the conductive interface, leading to an increase in the local current density amplitude at the physical interface edge. This increase in local current density enhances the targeted Joule heating rate per unit volume, accelerating the phase change cross-linking reaction of the outer thermoplastic insulating polymer matrix. The application of modified two-phase fluid materials enables the assembly equipment to permanently lock the internal morphology of the microcavity structure with shorter RF signal injection time or lower RF injection power. Within the aforementioned doping ratio range, the increase in high-frequency insertion loss of the interconnect node is within an acceptable engineering range and does not affect the normal transmission performance of the RF signal.

[0071] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A modular assembly method for a data transmission radio frequency front-end device, characterized in that, The assembly equipment interconnects and assembles radio frequency components with the motherboard, and performs modular assembly processes based on a microfluidic physical architecture; The microfluidic physical architecture includes: The motherboard has metal pads inside and metal pins outside the radio frequency components to be assembled forming a semi-closed microcavity structure at the docking position. The microcavity structure serves as an interconnection node for main signal transmission. Several blind-end microchannels are disposed on the sidewall of the microcavity structure and extend outward along the horizontal or vertical direction of the motherboard; A piezoelectric ceramic surface acoustic wave transducer array is embedded in the periphery of the microcavity structure and the blind-end microchannel; A two-phase fluid material, used as a filling medium, is composed of two parts: an inner layer of phase change conductive alloy and an outer layer of thermoplastic insulating polymer matrix. The modular assembly method includes the following steps: Step S100, Mechanical pre-locking and closed-loop verification circuit establishment: The assembly equipment places the radio frequency component into the assembly slot of the motherboard and applies normal clamping force to complete mechanical pre-locking. The closed-loop verification circuit is constructed by contacting the preset test lead on the motherboard through the external test probe. The closed-loop verification circuit injects a low-power continuous wave test signal into the interconnect node to establish the comparison reference data of reflection parameters. Step S200, initial injection of liquid medium driven by acoustic wave: the piezoelectric ceramic surface acoustic wave transducer array is activated to generate acoustic field standing wave. Under the direct action of the acoustic radiation force generated by the acoustic field standing wave, the two-phase fluid material is directionally pumped into the interconnect node to fill the air gap inside the microcavity structure and establish an initial physical electrical connection. The closed-loop verification circuit obtains the voltage reflection coefficient and voltage standing wave ratio parameters of the interconnect interface in real time. Step S300, Fluid topology reconstruction and verification within the microchannel network: When the extracted voltage standing wave ratio parameter fails to reach the preset impedance qualification threshold, the assembly equipment calculates the in-situ compensation amount required to achieve characteristic impedance matching based on the impedance offset, adjusts the excitation state of the piezoelectric ceramic surface acoustic wave transducer on the corresponding blind-end microchannel side, and uses acoustic wave pressure to drive the phase change conductive alloy into or out of the corresponding blind-end microchannel to the calculated target filling length, forming an equivalent stub structure inside the blind-end microchannel until the reflection parameter approaches the minimum value range and the characteristic impedance matching state is achieved; Step S400, Material Phase Change and Assembly Morphology Targeting Locking: The closed-loop verification circuit switches its operating mode to inject high-power continuous wave radio frequency energy into the interconnect node, inducing a local current congestion effect at the micro-geometric abrupt change at the junction of the microcavity structure and the equivalent stub structure, and targeting the generation of local Joule heating in the conductive junction region. When the interface temperature exceeds the phase change temperature threshold of the outer thermoplastic insulating polymer matrix, the thermoplastic insulating polymer matrix undergoes an irreversible molecular cross-linking reaction and transforms into a rigid solid insulating medium, thus performing in-situ three-dimensional physical encapsulation of the phase change conductive alloy in the ideal high-frequency matching morphology.

2. The modular assembly method for the data transmission radio frequency front-end device according to claim 1, characterized in that, In step S100, the test lead has been physically and electrically connected with the internal interconnection node during the motherboard wiring stage; The test probe integrates both an RF test port and a transducer drive port; the motherboard surface has a pre-installed transducer excitation pad, which is electrically connected to the piezoelectric ceramic surface acoustic wave transducer array through internal wiring; when the test probe contacts, the transducer drive port and the transducer excitation pad are correspondingly attached to transmit drive electrical signals, and the tail end of the RF test port of the test probe is connected to the signal generation source and the reflection parameter receiving device through a high-frequency coaxial cable to form the physical hardware link of the closed-loop verification circuit.

3. The modular assembly method for the data transmission radio frequency front-end device according to claim 1, characterized in that, The motherboard has a pre-installed liquid storage tank and connecting microchannels. The liquid storage tank stores the two-phase fluid material in advance, and the connecting microchannels connect the liquid storage tank and the microcavity structure to provide a physical path for fluid injection. The phase change conductive alloy is a gallium indium tin alloy fluid that remains liquid at room temperature or a gallium-based fluid doped with nano-conductive particles; the thermoplastic insulating polymer matrix is ​​a thermosensitive cross-linked resin.

4. The modular assembly method for the data transmission radio frequency front-end device according to claim 1, characterized in that, In step S300, the blind-end microchannel is divided into open-circuit blind-end microchannel and short-circuit blind-end microchannel according to the terminal structure: According to microwave transmission line theory, if the phase change conductive alloy is driven into the short-circuit blind-end microchannel with a solid sealed metal wall at the end of the channel, the target physical advancement length and the equivalent compensation susceptance, the characteristic admittance of the interconnect node and the phase constant of the radio frequency signal follow the standard cotangent function mapping relationship of the short-circuit stub. If the phase change conductive alloy is driven into the open-circuit blind-end microchannel that is connected to the pre-set insulating air cavity inside the motherboard at the end of the channel, the target physical advancement length and the equivalent compensation susceptance, the characteristic admittance of the interconnect node and the phase constant of the radio frequency signal follow the standard tangent function mapping relationship of the open-circuit stub.

5. The modular assembly method for the data transmission radio frequency front-end device according to claim 1, characterized in that, In step S400, the specific power range of the high-power continuous wave radio frequency energy is configured to be 10W to 50W, and the duration of a single injection is configured to be 1ms to 10ms. The targeted local Joule heat diffuses to the outer surface of the phase change conductive alloy and conducts to the outer edge within milliseconds. During the solidification phase change process, the rigid solid insulating medium formed presses and fixes the phase change conductive alloy to the inner wall of the microcavity structure through the wrapping constraint force and interface bonding force.

6. The modular assembly method for the data transmission radio frequency front-end device according to claim 1, characterized in that, The blind-end microchannels are provided with at least two on the sidewall of the microcavity structure, and the planar arrangement configuration includes any one of the following: cross-shaped configuration, annular radial configuration, or multi-level bifurcation configuration, forming a multi-degree-of-freedom adjustable microchannel network. Each of the blind-end microchannels is independently equipped with interdigitated electrodes that excite acoustic standing waves on its sidewalls. The multi-level bifurcated configuration is that a main blind-end microchannel extends a set distance to derive at least two secondary blind-end microchannels.

7. The modular assembly method for the data transmission radio frequency front-end device according to claim 6, characterized in that, In step S300, when the parasitic susceptance caused by mechanical assembly tolerance exceeds the upper limit of the compensation susceptance corresponding to the maximum filling length of a single blind-end microchannel, an extended matching process is performed: The closed-loop verification circuit decomposes the total target compensation susceptance required to achieve characteristic impedance matching into a set of sub-compensation susceptances of multiple parallel branches according to the allocation rules preset in the control program; the allocation rules are either weighted allocation according to the maximum effective filling volume ratio of different blind-end microchannels, or equal allocation to symmetrical blind-end microchannels with the same physical structure. The allocated sub-compensation susceptance sets are mapped to the blind-end microchannels in different spatial orientations to independently calculate the target physical propulsion length. The piezoelectric ceramic surface acoustic wave transducers in the corresponding orientations are driven synchronously or sequentially in time periods, forming a distributed radio frequency matching network at the interconnection node, which is composed of multiple equivalent stub structures connected in parallel.

8. The modular assembly method for the data transmission radio frequency front-end device according to claim 1, characterized in that, In step S100, the specific numerical range of the normal clamping force is set to 0.5N to 2.5N, and the assembly equipment maintains the normal clamping force until the modular assembly process ends to prevent the microcavity structure from failing. In step S104, the power of the low-power continuous wave test signal is strictly limited to between -20dBm and 0dBm.

9. The modular assembly method for the data transmission radio frequency front-end device according to claim 1, characterized in that, The phase change conductive alloy contains uniformly distributed high magnetic permeability nanoparticles with a mass fraction of 0.5% to 3%, constituting a modified two-phase fluid material. The high magnetic permeability nanoparticles are specifically made of nano-nickel powder or nano-iron powder.

10. The modular assembly method for the data transmission radio frequency front-end device according to claim 9, characterized in that, Doping with the high-permeability nanoparticles alters the physical parameter modulation properties of the two-phase fluid material: When performing step S200, doping the high-permeability nanoparticles increases the overall equivalent density of the phase change conductive alloy, increases the density difference with the thermoplastic insulating polymer matrix, and increases the absolute value of the acoustic contrast factor to apply a greater acoustic radiation force to the phase change conductive alloy. When performing step S400, the doping of the high permeability nanoparticles increases the overall equivalent permeability of the phase change conductive alloy, thereby reducing the microwave skin depth of the phase change conductive alloy. This forces the high-frequency current to concentrate more towards the outer surface of the conductor at the location of the geometric abrupt change in cross-section, and improves the heat generation rate of targeted local Joule heating by compressing the effective conductive cross-sectional area of ​​the conductive interface.

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