Through analyzing different cross-sections of the complex ball grid array (CBGA) sandwiched by silicon interposers, various distributed capacitances of the CBGA and the significance of the CBGA's coplanar capacitances are revealed. From the analyses, the composition of the CBGA's capacitance is found to have similarity with that of the coplanar waveguide's capacitance. Based on the electric-field coupling mechanism of the coplanar waveguide, geometrical analysis of the CBGA, and analysis of multiconductor transmission lines, analytical equations are derived to allow accurate modeling the equivalent circuit of the CBGA for 3D silicon-interposer packaging. The modeled equivalent circuit of the CBGA is validated with the full wave electromagnetic simulation, and it is demonstrated to have a good accuracy up to 40 GHz. Moreover, the CBGA structure can be further optimized for impedance matching with the guidance of the derived analytical equations.

AbstractAn equivalent circuit modelling methodology for the ball‐grid‐array (BGA) transition is proposed and validated with full‐wave electromagnetic simulation and measurement results. The BGA transitions modelled with the proposed methodology are validated to have a good accuracy up to 40 GHz. Unlike the existing BGA modelling methodologies which cannot model the BGA transition with short transmission lines within the anti‐pad region, the proposed methodology is developed from the practical BGA modelling scenario and models the irregular‐shape solder pads with transmission lines within the anti‐pad region. The BGA transitions modelled with the proposed methodology can be used for accurate and fast signal integrity simulations, analyses, and optimizations on 2.5D and 3D packaging. Additionally, factors impacting the accuracy of the equivalent circuit model are revealed by the proposed methodology.

随着集成电路制程趋于极限,登纳德缩放定律逐步失效,芯片的功率密度逐渐提升,尤其是在5G、物联网以及高性能计算快速发展的驱动下,单芯片面积也在增大,热耗散问题日趋严重,传统的冷却方式已无法保证芯片的可靠工作.将热沉制备在芯片内部可以避免封装材料的导热热阻和多层界面热阻,提升冷却性能和冷却效率.学术界针对芯片的嵌入式微流体冷却开展了大量卓有成效的研究和探索,不断提出新型通道结构设计方案,包括平行长直通道、歧管通道、射流通道等.旨在于优化泵功和热阻,在小压降下实现高效冷却.然而,随着芯片面积的增大,在限域空间实现高效冷却将更加困难,工艺难度和制造成本限制了嵌入式液冷的大规模商业化使用,目前在实际IC芯片内演示的冷却方案验证了嵌入式冷却的性能,但复杂度高,兼容性差,冷却性能有待进一步提升.尤其是在3D封装架构下,需要提出兼容小型化、高密度封装的通道结构,通过协同设计,在保证电学互连的前提下实现层间冷却.在优化通道结构设计的同时,还需要简化工艺,降低成本,提升嵌入式微流体冷却的工艺可靠性和长期工作可靠性,才能推进嵌入式微流体冷却技术的实际应用.

微系统技术是后摩尔时代延续摩尔定律重要的解决途径,能够满足电子装备对小型化、多功能电子系统的迫切需求.由于国内外基础工业条件及布局存在较大差异,无法将国外微系统技术路线全盘复制,应立足国内集成电路产业及封测产业的现状,走适合中国国情的自主可控技术路线.本文从微系统产品设计、制造及测试的研制流程出发,重点对微系统设计仿真、先进封装和集成测试等方面的关键技术展开研究,形成了 自主创新的关键技术解决思路,并提出了微系统的未来发展预判.

Advanced packaging technology based on TSV interposer becomes more and more important in microsystem integration. Electrical performance is one of the primary concerns in microsystem packaging design. The electrical characteristics of materials and process variation determine the voltage drop and transmission of high-speed and high-frequency signal. In this paper, simulation and test fitting of scattering parameter (S-parameter) and multi-objective comprehensive optimization method is proposed to characterize polyimide (PI) used in the TSV interposer. According to the original dielectric constant (Dk) and dissipation factor (Df) of PI, embedded single-ended microstrips are designed through simulation to obtain low reflection transmission and fabricated. In our method, Dk and Df of PI and conductivity of copper are set as variables to be optimized. Djordjevic-Sarkar model is adopted for frequency-dependent performance of Dk and Df. The simulation and measurement results including magnitude and phase of insertion loss, return loss and direct-current (DC) resistance are fitted well to extract the material characteristic curves. As a result, frequency-dependent curves of Dk and Df from 10MHz to 40GHz and the conductivity of copper are given. In additional, the influence of surface roughness has been integrated in Df and conductivity, which is more suitable and convenient for the engineering application.

This paper studies the extraction of text-oriented event information,establishes an event information extraction system.This system filters original corpus contain keywords firstly,obtains initial patterns using the method combined with hierarchical clustering(HCL) and the algorithm of longest common subsequence secondly,and then obtains final patterns contain Key words.Using these patterns information can be extracted and elements of event can be obtained finally.

The management information system of information and communication center is inspired by State Grid 186(For SG186,1 represents the integration of enterprise information integration platform,8 represents eight major business application systems used by the corporate system managing needs,6 represents six information security systems).The system is developed as an internal integrated business system according to the actual demands of information and communication center in Weinan Power Supply Bureau.This system is developed by the platform of ASP.NET,C# language and SQL Server database,which redevelops and integrates seven major business systems developed gradually since 2000,in order to achieve single sign-on.Using this unified platform can access multiple subsystems simultaneously,realize data sharing between systems and solve the tedious login problems.