Millimeter wave AiP low-loss packaging method and system based on three-dimensional integration

Abstract

The invention discloses a millimeter wave AiP low-loss packaging method and system based on three-dimensional integration, and relates to the technical field of millimeter wave packaging, and the method comprises the following steps: in a three-dimensional integrated packaging structure, building an interlayer heat conduction balance belt around a three-dimensional interconnection region which is liable to generate electrothermal coupling abnormity under a transient temperature gradient, the heat conduction balance belt preferentially absorbs local heat at the initial stage of temperature sudden change to form an impedance stable buffer area; a current slow-release channel is arranged on the local temperature rise path based on the impedance stable buffer area, so that the current slow-release channel releases high-frequency energy in a segmented manner along the boundary of the impedance stable buffer area. Through collaborative design of the heat conduction balance belt and the current slow release channel, rapid absorption and shunting of transient energy are realized, and impedance and heat flow are kept stable; and through multi-stage regulation and control of the reverse phase coupling ring and the energy dissipation layer, the energy diffusion direction and the temperature distribution are accurately controlled, and the thermal stability and the long-term reliability of packaging are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of millimeter-wave packaging technology, and more specifically to a millimeter-wave AiP low-loss packaging method and system based on three-dimensional integration. Background Technology

[0002] Three-dimensional integrated millimeter-wave AiP low-loss packaging is a radio frequency front-end packaging method for high-frequency communication scenarios. Its core is the compact arrangement of antennas, RF channels, and active chips in a three-dimensional structure using a stacked configuration and lateral interconnections, enabling signal coupling and radiation along the shortest transmission path within the package. By introducing low-loss dielectrics, fine interconnect transition structures, and energy-absorbing shielding walls within the three-dimensional stack, energy loss of millimeter-wave signals during long paths, interface transitions, and parasitic coupling is reduced. Simultaneously, the physical proximity of the antenna and chip improves feeding efficiency, resulting in higher gain, lower insertion loss, and stronger anti-interference capabilities at high frequencies, thus meeting the high-performance millimeter-wave requirements of high-bandwidth communication, automotive radar, and mobile terminals.

[0003] The existing technology has the following shortcomings: In existing technologies, three-dimensional interconnects are prone to electrothermal coupling anomalies under transient temperature gradients, leading to a sudden increase in the interconnect cross-sectional impedance within a very short time. During this impedance rise phase, self-excited channels are induced within the package. These self-excited channels cause millimeter-wave energy to continuously fold back and accumulate along the stack-up gaps within nanosecond timescales, gradually forming a high-density energy circulation region. When the transient energy in this energy circulation region exceeds the material's carrying capacity limit, a sudden energy impact is released towards the bottom of the active chip, causing localized ablation damage to the chip without warning. This severely impacts the overall reliability and safety of the millimeter-wave package.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a millimeter-wave AiP low-loss packaging method and system based on three-dimensional integration to solve the problems in the background art mentioned above.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a millimeter-wave AiP low-loss packaging method based on three-dimensional integration, comprising the following steps: Step 1: In the three-dimensional integrated packaging structure, an interlayer thermal equilibrium band is constructed around the three-dimensional interconnect region where electrothermal coupling anomalies are prone to occur under transient temperature gradients. This allows the thermal equilibrium band to preferentially absorb local heat in the early stage of temperature change, forming an impedance stabilization buffer. Step 2: Relying on the impedance stabilization buffer, a current release channel is set up on the local temperature rise path, so that the current release channel releases high-frequency energy in segments along the boundary of the impedance stabilization buffer to suppress the instantaneous focusing of energy in space and provide a transition interface for subsequent phase modulation. Step 3: Based on the transition interface formed by the current release channel, a dynamic reverse phase coupling ring is established between the stacked gaps. The reverse phase coupling ring pulls the residual energy released through the current release channel in the reverse direction to disperse the energy back accumulation trend and form a controlled energy diffusion direction. Step 4: Based on the energy diffusion direction formed by the reverse phase coupling ring, a timing-tunable energy dissipation layer is constructed inside the package. The energy dissipation layer diverts the energy pulse along the energy diffusion path on a nanosecond timescale to stabilize the energy flow trajectory and form an isolation buffer band at the bottom of the chip. Step 5: Based on the stable energy field formed by the isolation buffer zone, a thermal potential equilibrium window is introduced inside it. After the energy diffusion is completed, the thermal potential equilibrium window actively adjusts the local temperature distribution to weaken the conditions for the formation of the self-excited channel.

[0007] Preferably, the steps for constructing interlayer thermal equilibrium bands in a three-dimensional integrated packaging structure are as follows: In the three-dimensional interconnect region containing the radio frequency signal channel, a joint simulation analysis of thermal field and electric field is performed. Based on the transient heat flux density and current density distribution, the hot spot region of electrothermal coupling anomaly is determined, and a thermal conduction adjustment space with a thickness of 10 to 30 micrometers is reserved between the upper and lower stacks of the interconnect region. A composite medium consisting of boron nitride microplates, alumina microparticles and polyimide resin is filled into the thermal conductivity regulation space, so that the boron nitride microplates are oriented and arranged along the planar direction to form a transverse thermal conductivity channel. The interface between the thermally conductive balance band and the upper and lower metal interconnection solder layers is strengthened by nano-silver paste or copper plating to form a continuous heat flow channel. A heat potential distribution adjustment layer and a thermal stress relief zone are formed circumferentially in the thermal equilibrium zone. The adaptive diffusion of heat flow and stress relief are achieved through a multi-layer gradient thermal conductivity structure and a microchannel network.

[0008] Preferably, the heat potential distribution regulating layer adopts a gradient structure formed by sequentially stacking a high thermal conductivity copper plating layer, a medium thermal conductivity alumina-containing epoxy layer, and a low thermal conductivity polyimide composite layer, and microgrooves with a width of 2 to 5 micrometers are set at the interlayer interface to form a micro heat flow loop.

[0009] Preferably, the step of setting up a current release channel in the impedance stabilization buffer is as follows: Within the impedance-stabilized buffer zone formed by the thermal equilibrium zone, the path region with the highest energy density is determined through thermal field and electric field coupling simulation. The initial direction of the current release channel is preset along the main direction of heat flow outside the buffer zone, so that the current release channel is parallel to the boundary of the thermal equilibrium zone and the spacing is 5 to 15 micrometers. A copper-based composite thin layer with low resistance and high thermal conductivity is used to form a current release channel, and a titanium nitride barrier layer with a thickness of 0.3 micrometers is covered on its surface. This allows the current release channel to be connected to the top boundary of the thermal equilibrium zone in the vertical direction, so as to realize the instantaneous shunting of local current and energy release. A conductive field shaping control layer is set on the outer edge of the current release channel. This control layer is composed of a silver-copper alloy and a silicon oxide micro-medium to form a gradient conductive structure, and boron nitride nanosheets with a particle size of about 100 nanometers are embedded inside. An electrothermal energy transition interface is formed by controlling the edge morphology of the current release channel and the density gradient of conductive particles, and a zirconia potential equalization coating with a thickness of 0.2 micrometers is set on the outer wall.

[0010] Preferably, the thickness of the conductive field shaping control layer gradually decreases from the center to the edge, forming an arc-shaped gradient distribution structure, which causes the high-frequency electric field lines to bend continuously and diffuse smoothly when passing through this region, reducing energy reflection.

[0011] Preferably, the step of establishing a dynamic reverse phase coupling loop between the stacked gaps specifically includes: After the energy is released in segments through the current release channel, an electric field simulation analysis is performed on the gap region between the current release channel and the adjacent stacked medium. Based on the energy return path, a basic guide strip composed of a silver-copper composite thin layer is set up, and periodic trenches with a depth of about 0.2 micrometers and a spacing of about 1 micrometer are etched on its surface to form a reverse phase response region. A main reverse phase coupling ring is constructed on the inner wall of the stacked gap outside the guide strip. The coupling ring includes a gold-silver composite conductive ring, a palladium-plated buffer layer and a silicon oxide dielectric stabilizing layer in sequence. An indium tin oxide transparent conductive layer with a thickness of tens of nanometers is deposited on the surface of the conductive ring to enhance the reverse pull capability of high frequency energy. An auxiliary phase guiding band made of copper-tungsten composite conductor is set in the upper and lower boundary regions of the stacked gap, and a silver ion doped medium is embedded in the middle of the guiding band to form a phase compensation region, so that the reverse energy can propagate between the upper and lower layers in nanosecond time sequence to achieve dynamic traction. Adjust the spatial distribution ratio of the reverse phase coupling ring and the auxiliary phase guiding band, and the inclination angle of the ring edge to 3 to 5 degrees, so that the energy diffusion direction is unidirectionally biased.

[0012] Preferably, the indium tin oxide transparent conductive layer disposed on the surface of the gold-silver composite conductive ring of the main and reverse phase coupling ring has a thickness controlled in the range of 20 to 60 nanometers, and forms a synchronous phase response with the silver ion doped dielectric compensation region of the auxiliary phase guiding band.

[0013] Preferably, the step of constructing a timing-tunable energy dissipation layer inside the package specifically includes: After the reverse phase coupling ring forms a stable energy diffusion direction, a support base belt composed of a silicon carbide ceramic thin layer is laid in its outer edge region. The thickness of the thin layer is 3 to 8 micrometers, and aluminum nitride particles with a particle size of about 200 nanometers are doped into it. At the same time, a silver-copper alloy thermal grid is formed on the surface to achieve rapid capture and primary shunting of energy pulses. A timing control unit layer is constructed between the support baseband and the adjacent dielectric layer. This unit layer is composed of three types of composite material segments with alternating high diffusion, medium diffusion and low diffusion. A titanium nitride buffer layer with a thickness of about 100 nanometers is embedded at the interface of each segment to realize multi-stage delay and shunting of energy pulses in nanosecond time scale. A guide shunt layer made of copper-tungsten alloy is laid above the timing control unit layer, and striped thermal conductive trenches with a depth of about 0.3 micrometers are etched on the surface. It is combined with the lower layer through a silver-based intermediate connecting layer to ensure that energy is spread evenly along the diffusion direction. An isolation buffer zone consisting of a silicone rubber composite elastic layer and a silicon nitride ceramic heat-insulating layer with a thickness of 5 to 10 micrometers is formed at the bottom of the energy dissipation layer, and a zirconium oxide transition film with a thickness of 0.1 micrometers is set between the two layers to achieve the absorption, dispersion and reflection of energy waves.

[0014] Preferably, the step of introducing a thermal equilibrium window inside the isolation buffer zone specifically involves: After a stable energy field is formed in the isolation buffer zone, a support skeleton made of copper-tungsten alloy is embedded in the main energy flow path. The skeleton is 2 to 4 micrometers thick and forms a honeycomb channel structure with a unit size of 3 to 5 micrometers inside. A silver-based adhesive film with a thickness of 100 nanometers is coated at the interface to ensure efficient heat exchange within nanoseconds. A phase change medium layer with a thickness of about 0.5 micrometers is deposited on the inner wall of the honeycomb channel supporting the skeleton. The medium layer is a metal phase change composite material doped with aluminum nitride with a phase change temperature of 150 to 180 degrees Celsius, and 0.1% tungsten microparticles are added to stabilize the phase change cycle process. A thermistor guiding film with a thickness of about 200 nanometers is covered outside the phase change medium layer. The thermistor guiding film is composed of a silver-doped zinc oxide nanofilm and a silicon oxide protective layer with a thickness of 50 nanometers is set on the surface. A heat reflux regulating ring made of copper-nickel alloy is set around the periphery of the thermistor guiding film. The regulating ring has a width of 10 to 15 micrometers and is connected to the support frame through micro solder points to form a macroscopic heat flow loop and maintain the dynamic balance of the overall temperature field.

[0015] The millimeter-wave AiP low-loss packaging system based on three-dimensional integration includes a thermal balance building module, a current slow release control module, a reverse phase coupling module, a timing energy dissipation and shunt module, and a thermal potential equalization adjustment module. Thermal equilibrium construction module: In the three-dimensional integrated packaging structure, an interlayer thermal equilibrium band is constructed around the three-dimensional interconnection region where electrothermal coupling anomalies are prone to occur under transient temperature gradients. This allows the thermal equilibrium band to preferentially absorb local heat in the early stage of temperature change, forming an impedance stabilization buffer. Current slow release control module: Relying on the impedance stabilization buffer, a current slow release channel is set up on the local temperature rise path, so that the current slow release channel releases high-frequency energy in segments along the boundary of the impedance stabilization buffer, so as to suppress the instantaneous focusing of energy in space and provide a transition interface for subsequent phase control. Reverse phase coupling module: Based on the transition interface formed by the current release channel, a dynamic reverse phase coupling ring is established between the stacked gaps. The reverse phase coupling ring reverses the residual energy released by the current release channel to disperse the energy back accumulation trend and form a controlled energy diffusion direction. Timing-adjustable energy dissipation and shunt module: Based on the energy diffusion direction formed by the reverse phase coupling ring, a timing-adjustable energy dissipation layer is built inside the package, so that the energy dissipation layer shunts the energy pulse along the energy diffusion path within a nanosecond time scale, thereby stabilizing the energy flow trajectory and forming an isolation buffer band at the bottom of the chip; Thermal potential equilibrium adjustment module: Based on the stable energy field formed by the isolation buffer zone, a thermal potential equilibrium window is introduced inside it. After the energy diffusion is completed, the thermal potential equilibrium window actively adjusts the local temperature distribution to weaken the conditions for the formation of self-excited channels.

[0016] The technical effects and advantages provided by the present invention in the above technical solution are as follows: This invention introduces a synergistic structure of interlayer thermal equilibrium bands and current relief channels within the package. This allows transient temperature rises during electrothermal coupling to be actively absorbed and shunted within nanoseconds, preventing excessive energy accumulation at interconnect cross-sections and layer interfaces, thereby effectively reducing electric field instability caused by impedance surges. This structure creates a dynamically balanced path for heat flow and current in space, significantly improving energy transmission continuity at high frequencies. It enables the package to maintain low-loss transmission characteristics even under high-power conditions, ensuring the stability and transmission efficiency of the RF link.

[0017] This invention achieves adaptive stabilization of energy diffusion direction and temperature distribution by establishing a multi-level energy control structure consisting of a reverse phase coupling loop and a time-tunable energy dissipation layer. This precisely constrains the energy flow trajectory within the package both temporally and spatially, significantly reducing the physical conditions for the formation of self-excited channels. Under high-power impacts, this method can actively disperse local thermal potential and maintain overall temperature field balance, fundamentally improving the thermal instability resistance and long-term reliability of the package structure. This ensures that the millimeter-wave package maintains low thermal resistance and high signal integrity in long-term operating environments. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a flowchart of the method for the millimeter-wave AiP low-loss packaging method based on three-dimensional integration according to the present invention.

[0020] Figure 2 This is a schematic diagram of the module of the millimeter-wave AiP low-loss packaging system based on three-dimensional integration of the present invention.

[0021] Figure 3 This is a flowchart illustrating the construction of interlayer thermal equilibrium bands in a three-dimensional integrated packaging structure according to the present invention.

[0022] Figure 4 This is a flowchart illustrating the current release channel set in the impedance stabilization buffer zone according to the present invention.

[0023] Figure 5 This is a flowchart illustrating the process of establishing a dynamic reverse phase coupling loop between the stacked gaps in this invention. Detailed Implementation

[0024] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that the description of this disclosure will be more complete and fully convey the concept of the exemplary embodiments to those skilled in the art.

[0025] This invention provides, for example Figure 1 and Figure 3-5 The millimeter-wave AiP low-loss packaging method based on three-dimensional integration shown includes the following steps: Step 1: In the three-dimensional integrated packaging structure, an interlayer thermal equilibrium band is constructed around the three-dimensional interconnect region where electrothermal coupling anomalies are prone to occur under transient temperature gradients. This allows the thermal equilibrium band to preferentially absorb local heat in the early stage of temperature change, forming an impedance stabilization buffer zone, so as to establish the initial balance condition between heat flow and impedance in the packaging structure. The specific implementation method is as follows: During the design phase of the 3D integrated packaging structure, precise joint thermal and electric field simulation analysis was performed on the 3D interconnect region containing the RF signal channel in the target package. Transient heat flux density distribution maps and current density distribution maps were used to identify hotspot regions where electrothermal coupling anomalies might occur under high-power operation. Based on the simulation results, a thermal conductivity adjustment space with a thickness of 10 to 30 micrometers was reserved between the upper and lower stacked layers of the interconnect region. This space was filled with a composite medium composed of boron nitride microsheets, alumina microparticles, and high-temperature resistant polyimide resin. The boron nitride microsheets were oriented along the planar direction to form a transverse thermal conductivity channel, while the alumina particles were uniformly distributed to enhance longitudinal thermal conductivity. The polyimide resin provided good dielectric stability and flexibility matching, enabling the entire material layer to form a continuous and controllable thermal conductivity path. This thermal equilibrium band, through its tight adhesion with the upper and lower metal interconnect solder layers, formed a heat flow channel in the vertical direction, allowing local heat to be rapidly conducted to adjacent low-temperature regions within microseconds, completing the primary diffusion of heat energy. To ensure efficient heat transfer, the interface of the thermal equilibrium zone is strengthened using nano-silver paste or copper plating, significantly reducing interfacial thermal resistance. This process creates a thermal equilibrium zone with high thermal conductivity while maintaining low dielectric loss, enabling stable heat transfer and uniform electric field distribution under high-frequency signals, thus laying the foundation for subsequent heat flow control.

[0026] After the thermal equilibrium zone is constructed, a thermal potential distribution regulating layer is formed around the interface between the thermally conductive layer and the adjacent interconnecting metal layers. This regulating layer adopts a multi-layer gradient composite structure, consisting of a high thermal conductivity material layer near the thermal equilibrium zone, a medium thermal conductivity material layer in the middle, and a low thermal conductivity material layer on the outer side, stacked sequentially. The high thermal conductivity layer is made of copper plating, the medium thermal conductivity layer is made of epoxy resin containing alumina powder, and the low thermal conductivity layer is made of polyimide-based composite medium. Through the structure of three layers with successively decreasing thermal conductivity, when temperature changes occur, heat energy can diffuse outward step by step, avoiding heat concentration in a single area and causing local overheating. The thermal potential distribution regulating layer is arranged in a closed ring along the circumference of the thermal equilibrium zone, making the transfer of heat energy in the lateral direction continuous and directional. When a sudden temperature change occurs, the thermal potential distribution regulating layer responds first, rapidly transferring heat through the high thermal conductivity layer, and then gradually diffusing it through the medium and low thermal conductivity layers, so that the temperature forms a smooth gradient transition in the planar direction, thereby suppressing thermal stress concentration. Meanwhile, several microgrooves with widths of 2 to 5 micrometers are set at the boundary of the thermal potential distribution adjustment layer. These grooves form micro-heat flow loops at the material layer interface. When sudden heat is generated, the microgrooves can provide additional heat diffusion paths at the microscale, making the local thermal potential distribution more uniform. Through this gradient heat conduction configuration, the thermal equilibrium zone can establish a stable heat flow path in the early stage of temperature change, which significantly reduces the temperature rise rate of the interconnect cross-section during transient processes.

[0027] After the thermal potential distribution regulating layer is formed, a thermal stress relief zone is introduced between the thermal equilibrium band and the interconnect metal layer to further alleviate the thermal stress concentration effect. This zone is made of a silicone rubber composite medium with plasticity and moderate thermal conductivity, and hollow glass microspheres with a diameter of approximately 200 nanometers are uniformly embedded within the material. The silicone rubber matrix provides elastic support, allowing the material to deform slightly in the vertical direction when heated to absorb stress concentration caused by temperature differences. The presence of the hollow glass microspheres creates air gaps at the microscale, reducing the overall thermal conduction velocity and partially dispersing the heat flow as it passes through this region. To enhance the uniformity of heat flow diffusion, a crisscrossing microchannel network is formed in the thermal stress relief zone using laser etching. The width of the microchannels is controlled to be approximately 3 micrometers, and the depth is approximately 5 micrometers. These microchannels connect the bottom of the thermal equilibrium band with the edge of the interconnect metal layer, enabling multidirectional heat flow diffusion. In this way, when the temperature rises suddenly, the heat is first absorbed by the thermal equilibrium zone and then diffuses along the thermal potential distribution regulating layer. Some of the heat flow is diverted through microchannels into the thermal stress relief zone, where it is dispersed into multiple heat flow units with lower energy density, thereby significantly reducing the peak thermal stress. This relief zone and the thermal potential distribution regulating layer form a closed-loop structure in geometry, which can cooperate with each other during transient temperature changes to achieve adaptive absorption and redistribution of energy through a reversible heat flow cycle, enabling the entire thermally conductive structure to quickly reach a thermodynamically stable state in a short time.

[0028] After constructing the thermal equilibrium band, thermal potential distribution adjustment layer, and thermal stress relief zone, a comprehensive optimization of material distribution, geometric layout, and interface bonding methods is performed to achieve synchronous balance between heat flow and impedance. In this stage, by adjusting the thickness ratio of the thermal equilibrium band, the gradient parameters of the thermal potential distribution adjustment layer, and the channel morphology of the thermal stress relief zone, the direction of heat transmission is aligned with the RF signal path, thus forming a coordinated working mechanism of heat flow and current coupling within the package. When high-frequency signals propagate within the interconnect channels and are accompanied by temperature rise, the thermal equilibrium band can absorb sudden heat within nanoseconds and diffuse it vertically, preventing localized high temperatures in the interconnect area. Simultaneously, the thermal potential distribution adjustment layer dissipates heat uniformly in the lateral direction, forming a stable thermal field gradient, keeping the impedance change of the interconnect cross-section within a minimal range. The thermal stress relief zone continuously absorbs thermal expansion stress during temperature fluctuations, preventing interface delamination or crack propagation between the metal layer and the dielectric layer. Through this continuous thermo-mechanical coordination process, the heat flow distribution and impedance state within the entire package structure remain in a controlled equilibrium. After the temperature surge ends, the thermal equilibrium zone and each layer of the structure automatically return to a steady-state heat transfer mode, ensuring that the interconnect impedance curve remains smooth and stable under high-frequency operating conditions, without sudden spikes. This process enables the 3D integrated package to maintain heat flow continuity and impedance consistency when facing high-power millimeter-wave excitation, significantly improving the thermal stability and RF reliability of the package. It provides stable initial conditions for subsequent energy mitigation and phase modulation stages, ultimately achieving low loss and high reliability performance of the millimeter-wave package structure during long-term operation.

[0029] Step 2: Relying on the impedance stabilization buffer, a current release channel is set up on the local temperature rise path, so that the current release channel releases high-frequency energy in segments along the boundary of the impedance stabilization buffer to suppress the instantaneous focusing of energy in space and provide a transition interface for subsequent phase modulation. The specific implementation method is as follows: After establishing the impedance-stabilized buffer zone formed by the thermal equilibrium band, a refined analysis of the temperature rise distribution characteristics within the buffer zone is performed. The path region with the highest energy density is determined through transient electric field and thermal field coupling simulation. Based on this distribution pattern, an initial orientation of the current release channel is pre-defined along the main heat flow direction outside the buffer zone, ensuring that the current release channel is spatially parallel to the boundary of the thermal equilibrium band and the spacing is controlled between 5 and 15 micrometers. The current release channel is made of a low-resistance, high-thermal-conductivity copper-based composite thin layer, covered with a 0.3-micrometer-thick titanium nitride barrier layer to reduce the skin effect of high-frequency signals. The channel is vertically connected to the top boundary of the thermal equilibrium band, enabling it to directly sense temperature rise changes and instantly shunt local current during electrothermal coupling. When high-frequency excitation generates instantaneous energy concentration, the current release channel is activated first, guiding part of the high-frequency current to the boundary region through its low-resistance characteristics, thereby reducing the current density peak in the central region and achieving a preliminary energy release effect. To improve current diffusion efficiency, the internal conductor particles of the current release channel adopt a directionally arranged grain structure. By using crystal orientation control technology, the long axis of the grain is aligned with the current transmission direction, thereby reducing the probability of electron scattering, further reducing channel loss and improving transient conductivity response speed.

[0030] After completing the initial layout of the current-releasing channel, an energy-segmented release zone is set around the interface between the thermal equilibrium zone and the current-releasing channel. This zone consists of multiple independent but continuous energy transition segments, each with a length controlled between 30 and 50 micrometers. The material used in the energy-segmented release zone is a conductive transition layer formed by a composite of silver-containing conductive microparticles and a dielectric coating, allowing the current to be dissipated in small amounts sequentially as it passes through different segments, thus forming a multi-stage energy attenuation chain along the longitudinal path. To ensure the smoothness of the current release process, an insulating buffer gap with a width of 2 to 3 micrometers is set between each segment. This buffer gap is formed of a high-dielectric-strength polyimide film, which can provide stable electrical isolation under high-frequency conditions. In this way, when the current enters the segmented release zone through the release channel, the high-frequency energy is no longer concentrated on a single cross-section, but is released step by step through each transition segment, causing the energy density to decrease exponentially along the path direction. Meanwhile, the heat absorbed by the thermal equilibrium zone during the temperature rise phase is conducted through the metal interconnect layer adjacent to the segmented release zone, enabling the current and heat flow to couple synergistically in space, thereby preventing the accumulation of electrical and thermal energy in the same local area. Through this structured energy segmentation method, the current slow-release channel not only has electrical conductivity but also thermal regulation characteristics, significantly improving the uniformity and stability of energy release.

[0031] After the energy segmentation release region is constructed, a conductive field shape control layer is established around the channel to further stabilize the spatial electric field distribution of the current release channel. This conductive field shape control layer is positioned between the current release channel and the impedance stabilization buffer zone boundary, and its material is a gradient conductive layer formed by a composite of silver-copper alloy and silicon oxide microdielectric. This control layer is spatially arc-shaped, with its thickness gradually decreasing from the center to the edge. This causes continuous bending and diffusion of high-frequency electric field lines as they pass through this region, thus forming a natural electric field gradient transition. Through this morphological design, high-frequency energy does not undergo abrupt reflection at the channel boundary but smoothly transitions along the conductive field shape control layer to the surrounding dielectric region, achieving flexible energy diffusion. To further enhance field shape stability, boron nitride nanosheets with a particle size of approximately 100 nanometers are uniformly embedded inside the control layer. These nanosheets can form a local potential barrier under the action of an electric field, reducing the risk of partial discharge caused by sudden increases in charge density. At this time, the current release channel can not only effectively divert high-frequency electrical energy, but also achieve spatial diffusion of energy and potential balance through coupling with the conductive field shaping control layer, so that the impedance of the channel maintains a smooth and continuous change curve along the path direction.

[0032] After establishing the conductive field shaping control layer, the overall structure of the current release channel is comprehensively optimized to form a complete electrothermal energy transition interface at the junction with the impedance stabilization buffer. This interface achieves smooth energy flow by controlling the channel edge morphology, material thickness, and conductivity gradient. Specifically, a chamfered transition structure is adopted at the contact edge between the channel and the buffer, with the chamfer angle controlled at approximately 45 degrees to reduce impedance abrupt changes in the high-frequency signal transmission path. The density of conductive particles inside the channel gradually decreases from the center to the edge, forming a transition gradient from a high-conductivity region to a medium-conductivity region, thus naturally creating a potential rise effect during current flow, making the energy transfer process smoother. Simultaneously, a 0.2-micron-thick potential equalization coating is applied between the outer wall of the current release channel and the contact surface of the encapsulation medium. This coating uses a thin layer of zirconium oxide with a high dielectric constant, and its function is to stabilize the surface potential after energy release and prevent local charge retention. When a high-frequency signal periodically acts on the current release channel, the channel can automatically adjust the charge distribution state according to changes in electric field strength, keeping the energy release process within a controlled range. Through the synergistic effect of the above structures, the current-releasing channel can achieve graded release and spatial diffusion of high-frequency energy in a short time, avoiding the instantaneous focusing of energy in a local area. Simultaneously, due to the continuously maintained temperature equilibrium state of the thermal equilibrium band, the current-releasing channel maintains stable resistance and thermal resistance matching throughout the entire operation, providing a smooth transition interface for the subsequent establishment of the reverse phase coupling structure. Through this process, a dual electrothermal-releasing path is formed within the three-dimensional integrated package, enabling high-frequency energy to be decomposed, conducted, and redistributed in a very short time, ensuring that the package structure achieves low-loss, low-coupling, and highly stable operating characteristics under high-power millimeter-wave operation conditions.

[0033] Step 3: Based on the transition interface formed by the current release channel, a dynamic reverse phase coupling ring is established between the stacked gaps. The reverse phase coupling ring pulls the residual energy released through the current release channel in the reverse direction to disperse the energy back accumulation trend and form a controlled energy diffusion direction. The specific implementation method is as follows: After the current-releasing channel completes its segmented energy release, to further stabilize the transmission direction of the released energy in space, geometric modeling and electric field simulation are performed on the gap region between the current-releasing channel and the adjacent stacked dielectric to determine the reflection distribution trajectory of residual energy inside the package. Based on the main energy return path, a dynamic reverse phase coupling ring-based guide band is set in the longitudinal direction of the stacked gap. This guide band consists of continuously distributed silver-copper composite thin layers with a thickness controlled between 0.5 and 1.5 micrometers and a width identical to the stacked gap to ensure no phase abrupt change occurs during electromagnetic wave transmission. This guide band extends in a ring along the end of the current-releasing channel and connects to the end conductor layer of the release channel via an edge electrical connection bridge, enabling the guide band to directly sense the residual high-frequency energy released by the release channel. To achieve the reverse traction effect, periodic fine grooves are etched on the surface of the guide strip. The grooves are approximately 0.2 micrometers deep and spaced approximately 1 micrometer apart. These grooves form a phase delay region in the high-frequency electric field, causing the propagation phase of the incoming energy to shift in the opposite direction relative to the main propagation direction, thus forming a preliminary reverse phase response region in space. Through this microstructure arrangement, the guide strip establishes a reverse propagating electric field component while sensing residual energy, providing an initial phase basis for the formation of the reverse phase coupling loop.

[0034] After the guide band is formed, a primary-reverse phase coupling ring is constructed around the inner wall region of the stacked gap. This coupling ring is composed of multiple layers of conductive ring paths stacked sequentially: an inner layer of gold-silver composite conductive ring, a middle layer of palladium-plated buffer layer, and an outer layer of silicon oxide dielectric stabilizing layer. The inner conductive ring directly responds to the high-frequency residual energy transmitted from the current release channel, the middle buffer layer controls the capacitive effect between adjacent conductive layers, and the outer dielectric stabilizing layer prevents high-frequency signal leakage and phase interference. The diameter of the primary-reverse phase coupling ring is designed to match the width of the stacked gap, typically 1.2 to 1.5 times the gap width, to cover the entire energy diffusion region. When the high-frequency residual energy enters the coupling ring region, the gold-silver composite conductive ring generates a reverse induced current under the action of an applied electric field. The phase of this induced current is opposite to that of the original energy wave, thus forming a reverse electric field component in space. Because the coupling ring has a ring structure, this reverse electric field is uniformly distributed along the ring direction, causing residual energy to be re-decomposed and diffused in multiple directions, no longer concentrated on a single propagation path, thus effectively suppressing energy reflection and accumulation. To enhance the reverse coupling capability, a transparent conductive layer of indium tin oxide with a thickness of tens of nanometers is deposited on the conductor surface of the coupling ring. This layer has stable electromagnetic transmission characteristics in the high-frequency band, which can improve the synchronous response speed of the coupling ring to the energy phase, making the reverse traction more efficient and stable.

[0035] After the formation of the primary and secondary phase coupling loops, auxiliary phase guiding strips are constructed at the upper and lower boundary regions of the stacked gaps to achieve dynamic traction and timing control of the reverse energy. These guiding strips are made of copper-tungsten composite conductors and are tightly bonded to the dielectric layer using precise thermal expansion coefficient matching technology to prevent thermal stress peeling under high-power excitation. The guiding strips maintain electromagnetic induction coupling with the primary and secondary phase coupling loops. The length of the guiding strips is adjusted according to the time delay characteristics of the energy propagation path, ensuring that the reverse energy propagates between different spatial layers in a nanosecond-level timing sequence. A phase compensation region is set in the middle of the guiding strips, embedding a thin dielectric layer doped with trace amounts of silver ions. When residual energy enters this region, the silver ions form a transient polarization structure under the influence of the electric field, thereby creating a controllable delay to the energy wavefront. Utilizing this controllable delay effect, the reverse energy can propagate in a progressive timing sequence between different stacked layers, achieving dynamic equilibrium of the reverse traction. Once the reverse energy in the upper guide band is released, the compensation region of the lower guide band immediately takes over the remaining energy, ensuring the continuity of the energy traction process. This coordinated upper and lower guide structure enables the entire reverse phase coupling loop to continuously follow the propagation rhythm of the residual energy under high-frequency conditions, achieving real-time control of the reverse energy traction and further optimizing the stability of the energy diffusion direction.

[0036] After the main and auxiliary phase coupling rings form a complete reverse traction network, the overall structure is precisely calibrated to maintain a stable phase response and energy diffusion path across different frequency bands. Controllable guidance of energy diffusion direction is achieved by adjusting the ring diameter, conductive layer thickness, and spatial distribution ratio of the guide strips. When high-frequency residual energy enters the reverse phase coupling ring through the current release channel, the energy wave is first decomposed into multiple reverse phase components in the main coupling ring, which diffuse radially within the annular space. Subsequently, some energy propagates upwards and downwards along the auxiliary guide strips, while some energy is laterally drawn along the annular path, ultimately forming a balanced distribution in multiple directions. Simultaneously, the dielectric stabilization layer on the outer layer of the coupling ring suppresses parasitic reflections during energy diffusion, preventing energy from refocusing and flowing back into the current release channel region. To enhance the controllability of energy diffusion direction, a micro-tilted guide surface with a guide angle of 3 to 5 degrees is designed at the edge of the reverse phase coupling ring, giving the reverse-diffused energy wavefront a clear directional bias, thus forming a unidirectional diffusion trend within the encapsulation space. Through this structural spatial control, the reverse phase coupling ring realizes the secondary diffusion and directional traction of energy from the current release channel to the stacked gap, so that the residual energy will not accumulate locally after being released, but will be guided to the energy dissipation area to complete the smooth diffusion.

[0037] After this process, the energy flow path inside the entire three-dimensional integrated package is effectively optimized, and the electrothermal energy shows an orderly diffusion trend in space, which significantly reduces the possibility of energy backflow and standing wave coupling. This ensures that the package maintains a stable electrothermal balance under high-frequency and high-power operating conditions, providing steady-state phase conditions for subsequent energy diversion and energy dissipation layer construction.

[0038] Step 4: Based on the energy diffusion direction formed by the reverse phase coupling ring, a timing-tunable energy dissipation layer is constructed inside the package. The energy dissipation layer diverts the energy pulse along the energy diffusion path on a nanosecond timescale to stabilize the energy flow trajectory and form an isolation buffer band at the bottom of the chip. The specific implementation method is as follows: After the reverse phase coupling ring is formed and a stable energy diffusion direction is established, an initial support baseband for the energy dissipation layer is set along the main energy diffusion path inside the package to achieve precise diversion and timing control of the diffused energy. This baseband is directly laid on the outer edge region of the reverse phase coupling ring, using a thin layer of silicon carbide ceramic with high thermal conductivity and electromagnetic stability, with a thickness controlled within the range of 3 to 8 micrometers to maintain structural strength while ensuring thermal diffusion efficiency. Aluminum nitride particles with a particle size of approximately 200 nanometers are uniformly doped into the silicon carbide thin layer, forming a stable dielectric channel under the action of a high-frequency electromagnetic field, allowing energy to propagate within the layer in a wave-like manner. This support baseband extends spatially along the diffusion direction of the reverse phase coupling ring and is fixed to the stacked dielectric layer at each overlap point by welding, thus forming a continuous energy conduction channel. To achieve nanosecond-level response to energy pulses, a thermally conductive grid made of silver-copper alloy is formed on the surface of the support baseband, with a grid width controlled within 5 micrometers and arranged in a crisscross pattern. Under transient heat flow, the thermal grid can quickly capture energy pulses from the reverse coupling ring and form multiple heat flow micro-loops between the grids, thus establishing a preliminary basis for energy diversion. This multi-channel heat flow structure enables the energy dissipation layer to have instantaneous response capabilities, laying the foundation for subsequent timing regulation.

[0039] After the supporting baseband is formed, a timing control unit layer is constructed around its internal heat flow distribution characteristics to achieve time-domain delay and diversion control of energy pulses. This timing control unit layer is located between the supporting baseband and the adjacent dielectric layer and consists of multiple sets of composite material segments with different thermal diffusivity coefficients, arranged alternately. The segment near the reverse phase coupling ring uses a silver-plated boron nitride-doped material to achieve a high diffusion rate; the middle segment uses an epoxy dielectric containing alumina particles to achieve medium-speed diffusion; and the segment away from the coupling ring uses a polyimide matrix containing silicon carbide microparticles to achieve low-speed diffusion. Through this multi-material gradient structure, the energy diffusion rate within the layer gradually slows down along the longitudinal direction, thus forming a continuous time-delay distribution. When an energy pulse from the reverse phase coupling ring enters this layer, the high-speed segment first absorbs most of the energy and conducts it rapidly, while the medium-speed and low-speed segments respond sequentially, forming a delay chain with a time difference of several nanoseconds. Due to the different thermal diffusivity coefficients between the segments, the energy pulse is naturally dispersed into multiple time phases, avoiding concentrated action on a local area at the same moment. To further stabilize this delay effect, a titanium nitride buffer layer with a thickness of approximately 100 nanometers is embedded between the interfaces of each segment. Titanium nitride exhibits excellent thermal stability at high temperatures, preventing energy pulse reflection at the interface. This timing-controlled structure enables the energy dissipation layer to achieve multi-stage energy diversion on a nanosecond timescale, providing precise timing control for subsequent energy trajectory stabilization.

[0040] After constructing the timing control unit layer, a guiding shunt layer is laid on the upper surface of the energy dissipation layer to ensure the spatial stability of the energy diffusion path. The guiding shunt layer is made of a copper-tungsten alloy-based thin film with a thickness of approximately 2 micrometers. Striped thermally conductive trenches extending along the energy diffusion direction are etched on its surface, with a trench spacing controlled between 3 and 5 micrometers and a depth of approximately 0.3 micrometers. The presence of these trenches guides the direction of energy propagation within the layer, causing energy pulses to flow along the trench direction after entering the energy dissipation layer, avoiding energy accumulation caused by lateral random diffusion. To ensure that the thermal conductivity of the guiding shunt layer is coordinated with the underlying timing control layer, a 0.2-micrometer-thick silver-based intermediate connecting layer is placed between the two layers. This connecting layer provides uniform interfacial thermal resistance during heat conduction, thereby maintaining a stable heat flux density distribution along the lateral direction. When an energy pulse enters the energy dissipation layer via a reverse phase coupling loop, it is first captured by the guiding shunt layer and guided to propagate along the trench direction. Subsequently, it is gradually delayed and shunted in the timing control unit layer, forming a continuous and controllable energy diffusion path. Through the synergistic effect of linear guidance from the shunt layer and multi-stage response from the timing layer, the energy flow trajectory is stably regulated in both space and time, significantly reducing the peak energy density at local points and ensuring uniform energy distribution within the encapsulation structure.

[0041] After the current distribution layer is formed, an isolation buffer zone is constructed at the bottom of the energy dissipation layer to prevent energy from penetrating further downwards into the chip's working area during transmission. The isolation buffer zone employs a double-layer structure: an upper layer of silicone rubber composite elasticity and a lower layer of silicon nitride ceramic thermal barrier. The upper silicone rubber composite elastic layer incorporates alumina microspheres with a diameter of approximately 300 nanometers. Its elastic structure can absorb localized thermal stress and slow down the energy wavefront velocity under high-power impacts. The thickness of the lower silicon nitride ceramic thermal barrier layer is controlled between 5 and 10 micrometers, and its high thermal resistance prevents further energy transmission to the bottom of the active chip. When an energy wave from the energy dissipation layer passes through the isolation buffer zone, the elastic layer first absorbs part of the impact energy and disperses it into multi-directional low-amplitude energy flows. The remaining energy is reflected and dissipated at the ceramic layer, thus forming a stable energy barrier at the bottom of the chip. To ensure long-term operational stability, a 0.1-micrometer-thick zirconium oxide transition film is placed between the silicone rubber layer and the ceramic layer. This transition film maintains interfacial bonding strength during high-temperature cycling, preventing interlayer delamination. Through the above structure, the isolation buffer band forms a synergistic effect of active heat insulation and energy blocking between the energy dissipation layer and the chip, effectively terminating the energy diffusion path before it reaches the chip.

[0042] Through the above steps, the time-tunable energy dissipation layer achieves precise control of energy in both spatial and temporal dimensions. When the residual energy released by the reverse phase coupling loop enters this layer, the energy pulse is first captured, then shunted, and then delayed and guided to diffuse, ultimately forming an isolation buffer band at the bottom of the chip, achieving controlled energy dissipation. The entire process is completed within a nanosecond timescale, ensuring a smooth and continuous energy flow trajectory within the package. This avoids transient temperature rises and structural damage caused by localized energy accumulation, significantly improving the operational reliability and shock resistance of the 3D integrated package under high-frequency and high-power operating conditions, and providing a stable foundation for subsequent thermal equilibrium control.

[0043] Step 5: Based on the stable energy field formed by the isolation buffer zone, a thermal potential equalization window is introduced inside it. After the energy diffusion is completed, the thermal potential equalization window actively adjusts the local temperature distribution to weaken the formation conditions of the self-excited channel and realize the long-term low loss and high reliability operation of the millimeter wave package under high power impact. The specific implementation method is as follows: After the isolation buffer zone is constructed and a stable energy field is formed, a supporting framework for the thermal potential equilibrium window is embedded inside the isolation buffer zone along the main energy flow path to achieve active local temperature control after energy diffusion. This supporting framework is made of a copper-tungsten alloy with high thermal conductivity and a low coefficient of thermal expansion, with a thickness controlled between 2 and 4 micrometers. A honeycomb channel structure is formed inside it using micro-etching technology. The unit size of the honeycomb channel is approximately 3 to 5 micrometers, with a depth of 1 micrometer. The channels are interconnected by micro-connecting ribs, forming a complete heat flow grid. This structure does not participate in heat flow distribution during the energy diffusion stage, but rather participates in thermal potential regulation as the carrier of the thermal potential equilibrium window after energy diffusion. When the energy diffusion layer completes pulse diversion, residual heat forms a temperature gradient inside the isolation buffer zone. The supporting framework of the thermal potential equilibrium window forms multi-point contact with the surrounding material through thermally conductive channels, allowing the heat flow to be redistributed in multiple directions, thereby achieving the initial conditions for thermal potential rebalancing. To prevent interfacial thermal resistance between the support frame and the isolation buffer strip, a 100-nanometer-thick silver-based adhesive film is coated at the contact interface. This film maintains excellent thermal coupling performance under high temperature conditions and ensures that the equalization window completes heat exchange within a nanosecond response time.

[0044] After the supporting framework is formed, a phase change dielectric layer with thermally responsive properties is deposited around the inner wall of its honeycomb channels. This dielectric layer is made of a metal phase change composite material doped with aluminum nitride, and its phase change temperature is controlled between 150 and 180 degrees Celsius, which is above the normal operating temperature range of the package but below the chip damage critical temperature. The phase change dielectric layer is approximately 0.5 micrometers thick and is uniformly formed on the inner wall of the honeycomb using an atomic layer deposition process. When the package is operating in a stable state, this phase change dielectric layer maintains a solid structure and has little impact on heat flow conduction. When the residual heat released from the energy diffusion layer accumulates in a local area, causing the temperature to rise, the dielectric layer will rapidly undergo a solid-liquid phase transition. The high fluidity of the liquid medium allows local heat to diffuse within the honeycomb channels at an extremely fast speed, thereby rapidly weakening the temperature peak. After the phase transition is completed, the liquid medium re-solidifies under the thermal conductivity of the external environment, forming a new thermal equilibrium state. To improve the stability of phase change cycling, 0.1% tungsten microparticles are incorporated into the phase change medium. These particles act as nucleation regulators at the solid-liquid interface, preventing overcooling or localized volumetric abrupt changes during the phase change process. This maintains the structural integrity and response consistency of the thermal potential equilibrium window throughout multiple cycles. Through this design, the thermal potential equilibrium window can actively sense and adjust the local temperature distribution after energy diffusion, achieving adaptive reduction of the thermal potential peak.

[0045] After the phase change medium layer is constructed, a thermistor-guided film is applied to the outside of the supporting framework and phase change layer to enhance the thermal response sensitivity and spatial equalization capability of the thermal potential equilibrium window. This thermistor-guided film consists of a silver-doped zinc oxide nanolayer with a thickness of approximately 200 nanometers, and its internal silver ion distribution exhibits temperature-dependent characteristics. When the temperature in a localized area increases, silver ions migrate along the temperature gradient under the combined influence of the electric and thermal fields, forming spontaneously enhanced thermal conductivity channels. This causes heat flow to automatically shift towards lower-temperature regions, resulting in active guided heat transfer behavior. When the temperature decreases, the silver ions return to their equilibrium distribution state, restoring the heat conduction path to its initial shape, thus ensuring the reversible change of the thermal conductivity characteristics of the thermal potential equilibrium window between different operating states. To prevent changes in electrical performance caused by silver ion migration, a 50-nanometer-thick silicon oxide protective layer is applied to the surface of the thermistor-guided film to maintain electrical insulation and improve film stability. The thermistor guiding film and the underlying phase change medium layer together constitute a dynamic thermal response unit. The two complement each other during operation: the phase change layer undertakes the rapid release of sudden temperature peaks, while the thermistor film achieves continuous thermal potential equilibrium guidance, making the energy more uniform in spatial distribution and further weakening the temperature gradient conditions required for the formation of self-excited channels.

[0046] After the thermistor guiding film is formed, a heat recirculation regulating ring is installed around the entire periphery of the thermal potential equalization window to ensure structural stability and equalization accuracy under long-term operating conditions. This regulating ring, made of copper-nickel alloy, is 10 to 15 micrometers wide and 1 micrometer thick, and is distributed in a ring around the periphery of the thermal potential equalization window, connected to the edge of the support frame via multiple micro-soldering points. The function of the regulating ring is to collect residual heat flowing out from the outer edge of the thermistor guiding film and guide it to a lower temperature region, forming a macroscopic thermal circulation. Through the synergistic effect of this macroscopic heat recirculation and microscopic thermal potential regulation, the overall temperature distribution inside the package can recover to equilibrium in a short time, preventing new temperature gradients caused by localized heat accumulation. When the package experiences continuous high-power impacts, the internal phase change dielectric layer and the external thermistor guiding film of the thermal potential equalization window work alternately. The phase change process consumes the transient energy peak, the guiding process continuously disperses residual heat, and the regulating ring forms a long-term stable heat flow loop on the periphery, ensuring a dynamic equilibrium of the temperature field throughout the package. Through the combined effect of the above structures, the thermal potential equilibrium window not only has the dual characteristics of rapid response and long-term stability, but also actively weakens the temperature gradient concentration and energy reflection backflow effect after energy diffusion is completed, thereby completely destroying the necessary conditions for the formation of self-excited channels.

[0047] Through the above steps, the thermal equilibrium window forms an adaptive thermal control system within the package. This system can complete the entire process from energy sensing, phase change response, thermal potential guidance to heat flow recovery within a nanosecond to microsecond timescale. Once the energy diffusion layer transfers heat to the isolation buffer zone, the thermal equilibrium window immediately enters its working state. Through a multi-stage process involving support frame conduction, phase change medium absorption, thermistor guidance, and regulation loop recirculation, it achieves active balance of the local temperature field. This ensures that the package maintains low thermal resistance, low loss, and high reliability even after high-power surges, ultimately guaranteeing the thermal stability and structural safety of the millimeter-wave package in long-term high-frequency application environments.

[0048] This invention introduces a synergistic structure of interlayer thermal equilibrium bands and current relief channels within the package. This allows transient temperature rises during electrothermal coupling to be actively absorbed and shunted within nanoseconds, preventing excessive energy accumulation at interconnect cross-sections and layer interfaces, thereby effectively reducing electric field instability caused by impedance surges. This structure creates a dynamically balanced path for heat flow and current in space, significantly improving energy transmission continuity at high frequencies. It enables the package to maintain low-loss transmission characteristics even under high-power conditions, ensuring the stability and transmission efficiency of the RF link.

[0049] This invention achieves adaptive stabilization of energy diffusion direction and temperature distribution by establishing a multi-level energy control structure consisting of a reverse phase coupling loop and a time-tunable energy dissipation layer. This precisely constrains the energy flow trajectory within the package both temporally and spatially, significantly reducing the physical conditions for the formation of self-excited channels. Under high-power impacts, this method can actively disperse local thermal potential and maintain overall temperature field balance, fundamentally improving the thermal instability resistance and long-term reliability of the package structure. This ensures that the millimeter-wave package maintains low thermal resistance and high signal integrity in long-term operating environments.

[0050] This invention provides, for example Figure 2 The millimeter-wave AiP low-loss packaging system shown is based on three-dimensional integration and includes a thermal balance building module, a current slow release control module, a reverse phase coupling module, a timing energy dissipation and shunt module, and a thermal potential equalization adjustment module. Thermal equilibrium construction module: In the three-dimensional integrated packaging structure, an interlayer thermal equilibrium band is constructed around the three-dimensional interconnection region where electrothermal coupling anomalies are prone to occur under transient temperature gradients. This allows the thermal equilibrium band to preferentially absorb local heat in the early stage of temperature change, forming an impedance stabilization buffer. Current slow release control module: Relying on the impedance stabilization buffer, a current slow release channel is set up on the local temperature rise path, so that the current slow release channel releases high-frequency energy in segments along the boundary of the impedance stabilization buffer, so as to suppress the instantaneous focusing of energy in space and provide a transition interface for subsequent phase control. Reverse phase coupling module: Based on the transition interface formed by the current release channel, a dynamic reverse phase coupling ring is established between the stacked gaps. The reverse phase coupling ring reverses the residual energy released by the current release channel to disperse the energy back accumulation trend and form a controlled energy diffusion direction. Timing-adjustable energy dissipation and shunt module: Based on the energy diffusion direction formed by the reverse phase coupling ring, a timing-adjustable energy dissipation layer is built inside the package, so that the energy dissipation layer shunts the energy pulse along the energy diffusion path within a nanosecond time scale, thereby stabilizing the energy flow trajectory and forming an isolation buffer band at the bottom of the chip; Thermal potential equilibrium adjustment module: Based on the stable energy field formed by the isolation buffer zone, a thermal potential equilibrium window is introduced inside it. After the energy diffusion is completed, the thermal potential equilibrium window actively adjusts the local temperature distribution to weaken the conditions for the formation of self-excited channels.

[0051] The millimeter-wave AiP low-loss packaging method based on three-dimensional integration provided in this embodiment of the invention is implemented through the above-mentioned millimeter-wave AiP low-loss packaging system based on three-dimensional integration. For details of the specific methods and processes of the millimeter-wave AiP low-loss packaging system based on three-dimensional integration, please refer to the above-mentioned embodiment of the millimeter-wave AiP low-loss packaging method based on three-dimensional integration, which will not be repeated here.

[0052] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A millimeter-wave AiP low-loss packaging method based on three-dimensional integration, characterized in that, Includes the following steps: Step 1: In the three-dimensional integrated packaging structure, an interlayer thermal equilibrium band is constructed around the three-dimensional interconnect region where electrothermal coupling anomalies are prone to occur under transient temperature gradients. This allows the thermal equilibrium band to preferentially absorb local heat in the early stage of temperature change, forming an impedance stabilization buffer. Step 2: Relying on the impedance stabilization buffer, a current release channel is set up on the local temperature rise path, so that the current release channel releases high-frequency energy in segments along the boundary of the impedance stabilization buffer to suppress the instantaneous focusing of energy in space and provide a transition interface for subsequent phase modulation. Step 3: Based on the transition interface formed by the current release channel, a dynamic reverse phase coupling ring is established between the stacked gaps. The reverse phase coupling ring pulls the residual energy released through the current release channel in the reverse direction to disperse the energy back accumulation trend and form a controlled energy diffusion direction. Step 4: Based on the energy diffusion direction formed by the reverse phase coupling ring, a timing-tunable energy dissipation layer is constructed inside the package. The energy dissipation layer diverts the energy pulse along the energy diffusion path on a nanosecond timescale to stabilize the energy flow trajectory and form an isolation buffer band at the bottom of the chip. Step 5: Based on the stable energy field formed by the isolation buffer zone, a thermal potential equilibrium window is introduced inside it. After the energy diffusion is completed, the thermal potential equilibrium window actively adjusts the local temperature distribution to weaken the conditions for the formation of the self-excited channel.

2. The millimeter-wave AiP low-loss packaging method based on three-dimensional integration according to claim 1, characterized in that, The specific steps for constructing interlayer thermal equilibrium bands in a three-dimensional integrated packaging structure are as follows: In the three-dimensional interconnect region containing the radio frequency signal channel, a joint simulation analysis of thermal field and electric field is performed. Based on the transient heat flux density and current density distribution, the hot spot region of electrothermal coupling anomaly is determined, and a thermal conduction adjustment space with a thickness of 10 to 30 micrometers is reserved between the upper and lower stacks of the interconnect region. A composite medium consisting of boron nitride microplates, alumina microparticles and polyimide resin is filled into the thermal conductivity regulation space, so that the boron nitride microplates are oriented and arranged along the planar direction to form a transverse thermal conductivity channel. The interface between the thermally conductive balance band and the upper and lower metal interconnection solder layers is strengthened by nano-silver paste or copper plating to form a continuous heat flow channel. A heat potential distribution adjustment layer and a thermal stress relief zone are formed circumferentially in the thermal equilibrium zone. The adaptive diffusion of heat flow and stress relief are achieved through a multi-layer gradient thermal conductivity structure and a microchannel network.

3. The millimeter-wave AiP low-loss packaging method based on three-dimensional integration according to claim 2, characterized in that, The thermal potential distribution adjustment layer adopts a gradient structure formed by sequentially stacking a high thermal conductivity copper coating layer, a medium thermal conductivity alumina-containing epoxy layer, and a low thermal conductivity polyimide composite layer. Microgrooves with a width of 2 to 5 micrometers are set at the interlayer interface to form a micro heat flow loop.

4. The millimeter-wave AiP low-loss packaging method based on three-dimensional integration according to claim 2, characterized in that, The specific steps for setting up a current release channel in the impedance stabilization buffer are as follows: Within the impedance-stabilized buffer zone formed by the thermal equilibrium zone, the path region with the highest energy density is determined through thermal field and electric field coupling simulation. The initial direction of the current release channel is preset along the main direction of heat flow outside the buffer zone, so that the current release channel is parallel to the boundary of the thermal equilibrium zone and the spacing is 5 to 15 micrometers. A copper-based composite thin layer with low resistance and high thermal conductivity is used to form a current release channel, and a titanium nitride barrier layer with a thickness of 0.3 micrometers is covered on its surface. This allows the current release channel to be connected to the top boundary of the thermal equilibrium zone in the vertical direction, so as to realize the instantaneous shunting of local current and energy release. A conductive field shaping control layer is set on the outer edge of the current release channel. This control layer is composed of a silver-copper alloy and a silicon oxide micro-medium to form a gradient conductive structure, and boron nitride nanosheets with a particle size of about 100 nanometers are embedded inside. An electrothermal energy transition interface is formed by controlling the edge morphology of the current release channel and the density gradient of conductive particles, and a zirconia potential equalization coating with a thickness of 0.2 micrometers is set on the outer wall.

5. The millimeter-wave AiP low-loss packaging method based on three-dimensional integration according to claim 4, characterized in that, The thickness of the conductive field shaping control layer gradually decreases from the center to the edge, forming an arc-shaped gradient distribution structure, which causes the high-frequency electric field lines to bend continuously and diffuse smoothly when passing through this region, reducing energy reflection.

6. The millimeter-wave AiP low-loss packaging method based on three-dimensional integration according to claim 4, characterized in that, The specific steps for establishing a dynamic reverse phase coupling loop between the stacked gaps are as follows: After the energy is released in segments through the current release channel, an electric field simulation analysis is performed on the gap region between the current release channel and the adjacent stacked medium. Based on the energy return path, a basic guide strip composed of a silver-copper composite thin layer is set up, and periodic trenches with a depth of about 0.2 micrometers and a spacing of about 1 micrometer are etched on its surface to form a reverse phase response region. A main reverse phase coupling ring is constructed on the inner wall of the stacked gap outside the guide strip. The coupling ring includes a gold-silver composite conductive ring, a palladium-plated buffer layer and a silicon oxide dielectric stabilizing layer in sequence. An indium tin oxide transparent conductive layer with a thickness of tens of nanometers is deposited on the surface of the conductive ring to enhance the reverse pull capability of high frequency energy. An auxiliary phase guiding band made of copper-tungsten composite conductor is set in the upper and lower boundary regions of the stacked gap, and a silver ion doped medium is embedded in the middle of the guiding band to form a phase compensation region, so that the reverse energy can propagate between the upper and lower layers in nanosecond time sequence to achieve dynamic traction. Adjust the spatial distribution ratio of the reverse phase coupling ring and the auxiliary phase guiding band, and the inclination angle of the ring edge to 3 to 5 degrees, so that the energy diffusion direction is unidirectionally biased.

7. The millimeter-wave AiP low-loss packaging method based on three-dimensional integration according to claim 6, characterized in that, The indium tin oxide transparent conductive layer on the surface of the gold-silver composite conductive ring of the main and reverse phase coupling ring has a thickness controlled in the range of 20 to 60 nanometers, and forms a synchronous phase response with the silver ion doped dielectric compensation region of the auxiliary phase guiding band.

8. The millimeter-wave AiP low-loss packaging method based on three-dimensional integration according to claim 7, characterized in that, The specific steps for building a timing-tunable energy dissipation layer inside the package are as follows: After the reverse phase coupling ring forms a stable energy diffusion direction, a support base belt composed of a silicon carbide ceramic thin layer is laid in its outer edge region. The thickness of the thin layer is 3 to 8 micrometers, and aluminum nitride particles with a particle size of about 200 nanometers are doped into it. At the same time, a silver-copper alloy thermal grid is formed on the surface to achieve rapid capture and primary shunting of energy pulses. A timing control unit layer is constructed between the support baseband and the adjacent dielectric layer. This unit layer is composed of three types of composite material segments with alternating high diffusion, medium diffusion and low diffusion. A titanium nitride buffer layer with a thickness of about 100 nanometers is embedded at the interface of each segment to realize multi-stage delay and shunting of energy pulses in nanosecond time scale. A guide shunt layer made of copper-tungsten alloy is laid above the timing control unit layer, and striped thermal conductive trenches with a depth of about 0.3 micrometers are etched on the surface. It is combined with the lower layer through a silver-based intermediate connecting layer to ensure that energy is spread evenly along the diffusion direction. An isolation buffer zone consisting of a silicone rubber composite elastic layer and a silicon nitride ceramic heat-insulating layer with a thickness of 5 to 10 micrometers is formed at the bottom of the energy dissipation layer, and a zirconium oxide transition film with a thickness of 0.1 micrometers is set between the two layers to achieve the absorption, dispersion and reflection of energy waves.

9. The millimeter-wave AiP low-loss packaging method based on three-dimensional integration according to claim 8, characterized in that, The specific steps for introducing a thermal equilibrium window inside the isolation buffer zone are as follows: After a stable energy field is formed in the isolation buffer zone, a support skeleton made of copper-tungsten alloy is embedded in the main energy flow path. The skeleton is 2 to 4 micrometers thick and forms a honeycomb channel structure with a unit size of 3 to 5 micrometers inside. A silver-based adhesive film with a thickness of 100 nanometers is coated at the interface to ensure efficient heat exchange within nanoseconds. A phase change medium layer with a thickness of about 0.5 micrometers is deposited on the inner wall of the honeycomb channel supporting the skeleton. The medium layer is a metal phase change composite material doped with aluminum nitride with a phase change temperature of 150 to 180 degrees Celsius, and 0.1% tungsten microparticles are added to stabilize the phase change cycle process. A thermistor guiding film with a thickness of about 200 nanometers is covered outside the phase change medium layer. The thermistor guiding film is composed of a silver-doped zinc oxide nanofilm and a silicon oxide protective layer with a thickness of 50 nanometers is set on the surface. A heat reflux regulating ring made of copper-nickel alloy is set around the periphery of the thermistor guiding film. The regulating ring has a width of 10 to 15 micrometers and is connected to the support frame through micro solder points to form a macroscopic heat flow loop and maintain the dynamic balance of the overall temperature field.

10. A three-dimensional integrated millimeter-wave AiP low-loss packaging system, used to implement the three-dimensional integrated millimeter-wave AiP low-loss packaging method according to any one of claims 1-9, characterized in that, It includes a thermal conductivity balance construction module, a current slow release control module, a reverse phase coupling module, a time-sequence energy dissipation and diversion module, and a thermal potential balance adjustment module; Thermal equilibrium construction module: In the three-dimensional integrated packaging structure, an interlayer thermal equilibrium band is constructed around the three-dimensional interconnection region where electrothermal coupling anomalies are prone to occur under transient temperature gradients. This allows the thermal equilibrium band to preferentially absorb local heat in the early stage of temperature change, forming an impedance stabilization buffer. Current slow release control module: Relying on the impedance stabilization buffer, a current slow release channel is set up on the local temperature rise path, so that the current slow release channel releases high-frequency energy in segments along the boundary of the impedance stabilization buffer, so as to suppress the instantaneous focusing of energy in space and provide a transition interface for subsequent phase control. Reverse phase coupling module: Based on the transition interface formed by the current release channel, a dynamic reverse phase coupling ring is established between the stacked gaps. The reverse phase coupling ring reverses the residual energy released by the current release channel to disperse the energy back accumulation trend and form a controlled energy diffusion direction. Timing-adjustable energy dissipation and shunt module: Based on the energy diffusion direction formed by the reverse phase coupling ring, a timing-adjustable energy dissipation layer is built inside the package, so that the energy dissipation layer shunts the energy pulse along the energy diffusion path within a nanosecond time scale, thereby stabilizing the energy flow trajectory and forming an isolation buffer band at the bottom of the chip; Thermal potential equilibrium adjustment module: Based on the stable energy field formed by the isolation buffer zone, a thermal potential equilibrium window is introduced inside it. After the energy diffusion is completed, the thermal potential equilibrium window actively adjusts the local temperature distribution to weaken the conditions for the formation of self-excited channels.

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