From June 2021 to May 2024, three types of Beijing-3 series satellites have been launched successfully. The main payloads of these satellites are three types high-resolution cameras, which have excellent imaging quality. The camera thermal control systems operate stably, effectively ensuring high quality imaging of the cameras. The series of satellite payloads includes three different high-resolution cameras, which have both common requirements for high stability temperature control and different personalized needs for thermal control systems. Regarding the above requirement, this article introduces the thermal control design of camera optomechanical structure, internal heat source dissipation design, thermal analysis, thermal testing, core thermal control products. Analyzed the temperature data in orbit and evaluated thermal control system. On this basis, combined with practical needs, the applicant prospects of thermal control design methods in the field of commercial remote sensing were analyzed. A method for developing a thermal control system suitable for fast, low-cost, and mass production has been proposed.

Polymer insulation layers such as polyimide (PI) have gradually replaced inorganic dielectric layers (SiO2, SiCN) in the integrated packaging process of hybrid bonding (HB). PI can fill the gaps in the thermal compression bonding process and help to obtain a good Cu/Polymer bonding interface. At present, the existing post-crack double cantilever beam tensile test (PBC-DCB) has been successfully applied to the quantitative measurement of bonding strength of hybrid bonding with inorganic materials, but this method only considers elastic behavior. Since PI exhibits viscidity, elasticity and plasticity, knowing how to correlate these properties to the bonding process is challenging. Whether PBC-DCB is suitable for the characterization of PI bonding is unclear. This paper presents a comprehensive experimental and finite element analysis (FEA) study on the PI-PI bonding interface. Firstly, nanoindentation experiments and simulations are performed on the prepared PI interface to obtain key elasticity and plasticity parameters. Then, the bonding strength is characterized by the PBC-DCB test. Theoretical and experimental results show that the plasticity of PI causes energy dissipation during stretching, resulting in a deviation of approximately 2.51% compared with pure elasticity. Based on experimental data, the Cohesive Zone Model (CZM) FEA method is used to simulate the crack propagation. The results indicate that the Embedded Process Zone (EPZ) model can accurately describe crack initiation and delamination behavior, with a margin of error of about 3.61%. Finally, based on the EPZ CZM, defects such as bonding void and wafer warpage are further discussed in relation to bonding strength measurement.

Microstructure regulation of copper interconnects is the core key to improving the bonding performance for both thermal compression bonding and hybrid bonding in advanced microelectronic packaging. Nanocrystalline structures and (111)-oriented nanotwinned copper (nt-Cu) have been widely recognized as superior microstructure candidates for low-temperature direct bonding owing to their unique atomic diffusion advantages. In this work, two types of highly (111)-oriented nt-Cu were fabricated via electrodeposition. Combined with detailed characterizations using focused ion beam (FIB) and electron backscatter diffraction (EBSD), distinct microstructural features were identified in the two samples. One sample presents a typical columnar grain structure of (111)-oriented nt-Cu, while the other possesses a unique core-shell hybrid structure, in which columnar grains are uniformly encapsulated by surrounding nanoscale fine grains. The bonding experiments of the two nt-Cu specimens were conducted at 200 °C and 250 °C for 30 min under inert gas protection. Kernel average misorientation (KAM) analysis reveals that the intercolumnar fine grains effectively alleviate local strain concentration. Grain orientation spread (GOS) analysis further confirms that nanograins drastically promote atomic diffusion at the bonding interface and accelerate the elimination of the original interfacial boundary. Combinned with the Transmission elecron microscopy (TEM) observations, this work further elucidates the fundamental strengthening mechanism of core-shell nt-Cu: fine grains shell construct dense grain boundary diffusion network and optimize strain coordination simultaneously, driving the cross-interface growth of high-strength columnar cores. Shear tests demonstrate that the core-shell nt-Cu achieves markedly higher joint strength than traditional columnar nt-Cu at both bonding temperatures. The proposed microstructural design offers a practical route to high-performance, high-reliability low-temperature Cu direct bonding for next-generation microelectronic interconnections.

Fan-out wafer level packaging (FOWLP), an advanced packaging technology that can achieve high performance and miniaturisation, has become a subject of considerable research interest. As one of the important hightemperature steps in the FOWLP process, the influence of the sputtering step on the amount of wafer deformation is a key element in the study of the reliability of FOWLP. This study investigates the changes in warpage during the sputtering steps through both simulation and experimental approaches. Particularly, for the degassing chamber (Degas) that has the greatest impact on wafer warpage, the study analyzed its working principle and the mechanism of warpage formation. It is proposed that the primary causes of the warpage change in the Degas chamber are the maximum wafer temperature and the maximum temperature difference. Based on this, simulation and experimental studies were conducted on wafer temperature and warpage changes under different heat flow rate, while also considering silicon chip thickness ratio, to provide insights into more methods for mitigating wafer warpage in PVD (Physical Vapor Deposition) processes. The results of the study show that the wafer temperature is positively correlated with the heat flow rate and high wafer temperature can lead to wafer warpage greater than 5 mm, which is a great challenge to the process. In addition, the article uses simulation to verify the impact of wafer silicon chip thickness ratio on warpage, verifying the conclusion that the wafer warpage is the largest when the silicon chip thickness ratio is around 20 %-30 %.

To improve the accuracy and sensitivity of remote sensors, cryogenic optical technology has been widely developed in recent years. To achieve a low temperature of the optical-mechanical system of the remote sensor, necessary refrigeration schemes are required, with both radiation cooling and mechanical cooling requiring substantial resources. To reduce the refrigeration cost, controlling the thermal load of the cryogenic optical-mechanical system is the focus of the thermal control design. The space heat flow at the light inlet is an ever-present thermal load in cryogenic optical systems, especially for low-orbit remote sensors, which are subject to complex changes in the heat flow in space. Reducing the heat flow absorbed at the light inlet is an important part of the thermal control design of cryogenic optics. This paper presents the thermal control of a large-aperture cryogenic optical remote sensor. Aiming at the low-altitude and high-inclination orbit and cryogenic control of the remote sensor, the regularity of the spatial heat flow in different directions of the remote sensor is analyzed. Based on the mobility capability of the two-dimensional turntable, a heat flow avoidance strategy for the remote sensor light inlet is provided. To further reduce the impact of the light inlet heat flow on the cryogenic optical system, a shield is used to block the heat flow at the light inlet. This minimizes the spatial thermal load at the light inlet of the large-aperture cryogenic optical system, the foundation for the cryogenic realization of the entire optical system.

In recent years, selective laser-induced etching (SLE) has been recognized as the most promising method for through glass via (TGV) perforation. However, the morphology parameters of TGVs fabricated using SLE still mostly rely on empirical prediction. Also, there are still a series of morphology problems, such as irregularity and taper. This paper describes an experimental approach to systematically investigate the effect of various factors on the formation of TGVs. It was found that laser-induced cracks have a very significant impact on the final TGV formation quality. By reducing the length of the cracks, an optimization of the TGV irregularity can be achieved. Based on this, a physical model has been developed, which describes in detail the formation process of TGVs and explains the influence of laser-induced cracks on the TGV formation quality. Finally, a mathematical model is obtained by extrapolating from the physical model. This mathematical model enables accurate prediction of TGV morphology parameters by inputting several processing parameters.

This article introduces a low-cost compact W-band 4x4 phased array antenna utilizing fan-out wafer-level package (FOWLP) for high-performance applications. The package, measuring 8.3x7.1 mm, integrates a 16-channel transceiver die. To minimize the insertion loss and enhance impedance matching across the W band, the design incorporates an air-filled grounded coplanar waveguide (AF-GCPW) transmission line. An innovative thermal management strategy, which includes ball grid arrays (BGAs) and embedded copper slugs in the PCB, ensures efficient heat dissipation. Experimental results reveal that the array can achieve scanning capabilities of +/- 40 degrees in the H-plane and +/- 30 degrees in the E-plane, with an effective isotropic radiated power (EIRP) of 35 dBm at 94 GHz. The proposed phased array demonstrates superior performance compared to existing designs by reducing packaging loss, minimizing the number of metal layers, and enhancing cost-effectiveness. Consequently, it emerges as a promising solution for radar and sensing applications.

For large-aperture cryogenic optical remote sensors, this proposal outlines a thermal balance test layout and process design for heat pipes and radiators, considering ground testing constraints. Test conditions are set based on typical operational modes to fully validate the thermal control system. The design includes a detailed space simulation chamber and external heat flux analysis to match on-orbit conditions. By comparing test data with on-orbit performance, the ground tests effectively verify the thermal control system’s accuracy.

In this paper, a novel through mold via (TMV)-embedded fan-out wafer-level package (FOWLP) technology was demonstrated to manufacture the well-designed Antenna in Package (AiP) with ultrathin thickness (0.04 λ0). Double-sided redistribution layers (RDLs) were employed to build the patch antenna, while a TMV interposer was used to connect the front and back RDLs. By optimizing the AiP’s parameters, the patch antenna can achieve a wide impedance bandwidth of 17.8% from 24.2 to 28.5 GHz, which can cover the 5G frequency bands. Compared with previous works, the proposed AiP has significant benefits in terms of its ultralow profile, easy processing, and high gain. Hence, the TMV-embedded FOWLP should be a promising technology for fifth generation (5G) millimeter wave (mm-Wave) applications.

This article introduces a 94-GHz dual-polarized 1-D beamforming patch antenna array, specifically designed to achieve low sidelobe levels (SLLs) and an extensive scanning range. The array, in a 4x8 configuration, is capable of 1-D expansion and utilizes Ajinomoto build-up film (ABF) substrates alongside a precision electroplating process. This combination ensures high accuracy and fulfills the miniaturization demands for 94-GHz operations. A notable achievement of this research is the design of a compact power divider using a coupling line with short end, which establishes a large power dividing ratio. This design is pivotal in maintaining consistently low SLLs, typically below -18.2 dB and often below -20 dB, over the 92 similar to 96-GHz bandwidth within a 1x8 linear array. In addition, the array's transverse profile is optimized by altering the feeder angle, decreasing the distance between linear arrays to 0.52 lambda(0), where lambda(0) denotes the free-space wavelength at 94 GHz. The proposed 4x8 array design facilitates beam steering up to +/- 45(degrees) without grating lobes. The construction and experiments of the dual-polarized array antenna at 94.0 GHz validate its effectiveness, confirming the achievement of low SLL and extensive scanning capabilities in both polarizations.

For the packaging and integration of millimeter-wave monolithic integrated circuits, a fan-out wafer-level package (FOWLP) technology is developed. TMV arrays and molybdenum copper blocks are introduced to achieve good performance of vertical interconnection, grounding and thermal dissipation. A Ka-band low noise amplifier is packaged to demonstrate the proposed method. Within the frequency range of 24 similar to 33 GHz, the gain and the noise figure of the packaged chip are degraded by less than 1 and 0.1 dB, respectively, when compared with those of the die.

In this letter, a miniaturized Vivaldi antenna based on fan-out wafer-level packaging (FOWLP) process with a single redistribution layer (RDL) is proposed. A step-by-step design procedure for the proposed antenna is presented. By introducing the slots and semicircular-shaped loads, its low-end cut-off frequency is extended from 35.28 to 24.04 GHz, leading to a size reduction by 31.8% when normalized to the lowest operating frequency. Moreover, a wideband low-pass coplanar waveguide to slotline transition is proposed for antenna feeding, in which a folded split ring resonator and etching periodic slots are added to reduce the transition insertion loss above 40 GHz. Prototypes of the proposed antenna and back-to-back coplanar waveguide to slotline transition were fabricated and measured. The measured return loss of the BTB transition is better than 13.4 dB from DC to 67+ GHz, and the insertion loss of a single transition is below 0.95 dB. The measured |S11| of the proposed antenna is less than -10 dB from 23 to 67+ GHz with 4.5-7.1 dBi measured gain and >84% simulated efficiency.

Purpose This paper aims to realize the vertical interconnection in 3D radio frequency (RF) circuit by coaxial transitions with broad working bandwidth and small signal loss. Design/methodology/approach An advanced packaging method, 12-inch wafer-level through-mold-via (TMV) additive manufacturing, is used to fabricate a 3D resin-based coaxial transition with a continuous ground wall (named resin-coaxial transition). Designation and simulation are implemented to ensure the application universality and fabrication feasibility. The outer radius R of coaxial transition is optimized by designing and fabricating three samples. Findings The fabricated coaxial transition possesses an inner radius of 40 µm and a length of 200 µm. The optimized sample with an outer radius R of 155 µm exhibits S11 < –10 dB and S21 > –1.3 dB at 10–110 GHz and the smallest insertion loss (S21 = 0.83 dB at 77 GHz) among the samples. Moreover, the S21 of the samples increases at 58.4–90.1 GHz, indicating a broad and suitable working bandwidth. Originality/value The wafer-level TMV additive manufacturing method is applied to fabricate coaxial transitions for the first time. The fabricated resin-coaxial transitions show good performance up to the W-band. It may provide new strategies for novel designing and fabricating methods of RF transitions.

At present, perforation of high aspect ratio through glass vias (TGVs) is one of the primary factors limiting the development of glass interposers. This study is based on a large number of experiments, combined with mechanistic analysis, to realize the perforation of ultra‐high/high aspect ratio fused silica TGVs using selective laser‐induced etching (SLE). Firstly, the effect of the number of pulses as well as other laser parameters on the etching selectivity is systematically investigated. It is found that the formation of nanochannels in fused silica is crucial in determining the high selectivity. Subsequently, a model based on diffusion theory is proposed to mathematically explain the reasons for the high selectivity generation. Finally, the perforations of TGVs with diameters of 5.4 µm ‐ 26.4 µm, aspect ratios of 11.7 ‐ 61.3 and vertical sidewalls are achieved, at a laser treatment speed of approximately 10,000 TGVs per minute. This research can serve as an essential reference for the manufacturing of TGVs with high aspect ratios and glass interposers with high interconnection density.This article is protected by copyright. All rights reserved.

High temperature stability is an important parameter in thermal design of space cameras, because high resolution space cameras need highly stable thermal system. However, severe orbital thermal environment and complex satellite attitudes bring big challenges for thermal control of space camera. Traditional thermal control method can not meet high stability. Therefore, a novel thermal control method of high temperature stability is proposed to deal with the problem. Indirect radiation thermal control and differential temperature control method is applied for the structure of the camera, which significantly decreases temperature fluctuation and disturbance of external thermal environment. The in-orbit temperature data indicate that the temperature fluctuation of structures of the camera is better than ±0.2 °C and the mirrors are better than ±0.1 °C. The orbital temperature performance demonstrates that the thermal control method of high temperature stability for the high resolution space camera is reasonable and feasible and the thermal system satisfies the high stability demand. The novel method solves the demand of high thermal stability under harsh environment, and plays an important role in enhancing space camera resolution.

Abstract Adhesive bonding technology is the primary method for installing thermal control products on spacecraft. Studying the bonding methods of electric heaters at low temperatures has become particularly important. To validate the feasibility of GD-414 silicone rubber in bonding electric heaters at low temperatures, GD-414 silicone rubber tensile test specimens were designed and fabricated. After thermal testing, it was found that the peel strength and failure mode of the specimens changed after low-temperature storage at -120℃ and temperature cycling from -200℃ to 40℃. The peel strength of the specimens improved after pressure treatment, while the differences in peel strength between different metal substrates with the same roughness were not significant. The research findings demonstrate that GD-414 retains strong bonding performance even after low-temperature storage and temperature cycling, making it suitable for bonding electric heaters.

At present, perforation of high aspect ratio through glass vias (TGVs) is one of the primary factors limiting the development of glass interposers. Herein, it is based on a large number of experiments, combined with mechanistic analysis, to realize the perforation of ultrahigh/high aspect ratio fused silica TGVs using selective laser-induced etching. First, the effect of the number of pulses as well as other laser parameters on the etching selectivity is systematically investigated. It is found that the formation of nanochannels in fused silica is crucial in determining the high selectivity. Subsequently, a model based on diffusion theory is proposed to mathematically explain the reasons for the high selectivity generation. Finally, the perforations of TGVs with diameters of 5.4-26.4 mu m, aspect ratios of 11.7-61.3, and vertical sidewalls are achieved, at a laser treatment speed of approximate to 10 000 TGVs per minute. This research can serve as an essential reference for the manufacturing of TGVs with high aspect ratios and glass interposers with high interconnection density. This article demonstrates the application of ultrashort pulse lasers to create nanosized channels in fused silica. Following this, through wet etching, through glass vias (TGVs) with aspect ratios ranging from 11.7 to 61.2 are created. It allows for laser treatment speeds of up to 10 000 per minute, and resulting in vertical sidewalls.image (c) 2024 WILEY-VCH GmbH

This paper introduces a glass-based phased array antenna specifically designed for 5G millimeter-wave (mm-wave) antenna-in-package (AiP) applications. Leveraging the advanced glass integrated passive device (Glass-IPD) manufacturing process, a broadband L-shaped probe-fed magneto-electric (ME) dipole antenna is designed. To suppress higher-order modes and achieve stable radiation patterns with optimal gain at higher frequencies, the four corners of the square patches adjacent to the L-probe are trimmed. The antenna element boasts a compact size of 2.5mm x 2.5mm x 0.5mm, equivalent to 0.32 lambda x 0.32 lambda x 0.065 lambda at 39 GHz. Simulation results reveal that this antenna element possesses a 10 dB impedance bandwidth spanning 36 similar to 45GHz, comprehensively covering the 5G n259 (39.5 similar to 43.5GHz) and n260 (37 similar to 40GHz) bands. Across the entire frequency band, the antenna element's gain exceeds 6dBi, peaking at 6.5dBi at 39GHz. When configured into a 1x4 antenna array, the gain increases to 11.6 dBi at broadside and 9.6 dBi when the beam is steered at a 46-degree angle. The proposed antenna, which is based on glass material, offers a compact design, a broad operating frequency range, and excellent radiation characteristics. These features make it an appealing choice for 5G millimeter-wave applications.

In response to the heat dissipation requirements of space optical remote sensor electronics and other heat sources, the characteristics of the orbital heat flux of the high inclination orbit where the remote sensor is located are analyzed. Combined with the position characteristics of the remote sensor platform and the two-dimensional manoeuvring characteristics, the spatial layout position and required area of the heat dissipation radiator are determined. Utilizing heat pipe network to achieve the realization of the heat dissipation radiator groups, achieving effective heat dissipation of the heat source while the high orbital heat flux on the single position of the radiator. Adopting a non-metallic and graphite film composite heat dissipation radiator form, further improving the temperature uniformity of the heat dissipation radiator and effectively enhancing the heat dissipation of the remote sensor. Through this technology, the heat dissipation problem of complex orbit heat flux remote sensors can be solved.

In this letter, a novel co-linearly polarized full-duplex antenna-in-package (AiP) with high Tx/Rx isolation and wide decoupled bandwidth is proposed for integrated sensing and communication (ISAC). Fan-out wafer-level packaging technology is employed, and the preparation process is discussed in details. To improve Tx/Rx isolation, the current direction of the patch elements is orthogonal to that of the feeding ports. Two identical 1 × 2 patch antenna arrays are used as Tx and Rx antennas, respectively. To further suppress mutual coupling, a decoupling loop is proposed to enhance Tx/Rx isolation. In addition, a wideband full-duplex AiP with high isolation and wide decoupled bandwidth is also proposed by using the parasitic technique and the proposed decoupling method. Prototypes are fabricated and measured to verify the proposed AiPs. The measurement results demonstrate that the proposed AiP possesses the merits of high Tx/Rx isolation (up to 53 dB), wide isolation bandwidth (up to 9.2%) and low cost, providing a foundation for chip-level applications in ISAC.