埋入无源元件型玻璃基板的热回流制备及设计研究

发布时间：2018-11-26 09:23

【摘要】：系统级、微型化和低成本集成封装是微电子机械系统(Micro-electro-mechanical System,简称MEMS)封装的一大趋势,而封装基板技术为系统提供支持、保护和电互连作用,是三维(Three-dimensional,简称3D)系统级MEMS封装的关键技术。将无源元件埋入封装基板,是进一步减小MEMS系统封装体积的重要途径。在系统级MEMS封装基板材料中,玻璃具有低热膨胀系数、大光学带宽、高电阻率、气密性、防潮性、化学稳定性和低成本等优势,极具发展潜力。但是,玻璃的加工难度大,现有基板工艺也难以直接应用,因此亟需发展成套的MEMS封装玻璃基板加工技术以及设计方法。本论文基于热成型技术,提出一种埋入无源元件型MEMS封装玻璃基板的新型制备技术,并研究其设计方法。首先,本论文设计将导电通路、电阻、电容、电感、滤波器等埋置于玻璃基板内部,设计采用玻璃回流工艺制备埋入无源元件型玻璃基板。该设计充分利用基板内部空间,释放更多表面空间应用于3D集成,显著缩小封装体积。接着,本论文对埋入型基板设计思路进行实验验证。实验结果表明,所制备埋入玻璃基板元件的线宽为50-200um,厚度200um,可制备深宽比2.5的微结构。玻璃回流工艺利用高温熔融玻璃无孔洞包覆微结构,可大批量、低成本地制备埋入型玻璃基板,元件厚度高至上百微米,有效拓宽信号通路,减小电阻,而传统表面微加工工艺制备的元件最厚为20-30um。然后,本论文对埋入型基板设计思路进行HFSS仿真验证。仿真结果表明,采用导电TGV实现共面波导的3D互连结构损耗较低,可应用于实际生产。电感厚度增加可降低回波损耗和插入损耗,大幅度提高品质因数,小幅度减小有效电感,而玻璃回流工艺制备的埋入玻璃基板电感厚度可高至上百微米,验证了该工艺和该设计思路的实际应用价值。以高掺杂硅作为电感材料损耗较大,品质因数较低,不适合应用于实际生产。以铜作为电感材料电磁性能优良,不同结构电感具有不同范围的品质因数、有效电感和频率。随着厚度增加,电感品质因数增加率减小,到达一定厚度后存在品质因数滚降现象,而有效电感持续缓慢减小,因此,厚度作用范围并非无穷大。最后,本论文对设计、实验和仿真进行总结概括,并提出新的研究思路。
[Abstract]:System-level, miniaturization and low-cost integrated packaging is a major trend in microelectromechanical system (Micro-electro-mechanical System,) packaging, and packaging substrate technology provides support, protection and electrical interconnection for the system. It is a three-dimensional (Three-dimensional,) technology. The key technology of system-level MEMS encapsulation is referred to as 3 D. Embedding passive components into the packaging substrate is an important way to further reduce the packaging volume of MEMS systems. In the system-level MEMS packaging substrate, glass has the advantages of low thermal expansion coefficient, large optical bandwidth, high resistivity, gas tightness, moisture resistance, chemical stability and low cost. However, the processing of glass is difficult and the existing substrate process is difficult to be directly applied. Therefore, it is urgent to develop the complete set of MEMS packaging glass substrate processing technology and design method. Based on the thermoforming technology, this paper presents a novel fabrication technique of embedded passive element MEMS packaging glass substrate, and studies its design method. Firstly, the conductive path, resistance, capacitance, inductance, filter and so on are embedded in the glass substrate, and the passive element glass substrate is fabricated by glass reflux process. The design makes full use of the inner space of the substrate, freezes more surface space for 3D integration, and significantly reduces the packaging volume. Then, the design idea of embedded substrates is verified experimentally in this paper. The experimental results show that the linewidth and thickness of the embedded glass substrate elements are 50-200 um. and the thickness of the embedded glass substrate elements is 200um. the microstructure with the aspect ratio of 2.5 can be prepared. Glass reflux process can be used to fabricate embedded glass substrates in large quantities and low cost by using high temperature melting glass without holes to cover microstructures. The thickness of embedded glass substrates is as high as hundreds of microns, which effectively broadens the signal path and reduces the resistance. The thickness of the components prepared by the traditional surface micromachining process is 20-30 uma. Then, the design idea of embedded substrates is verified by HFSS simulation. The simulation results show that using conductive TGV to realize 3D interconnect structure of coplanar waveguide has low loss and can be used in practical production. With the increase of inductance thickness, the return loss and insertion loss can be reduced, the quality factor can be greatly improved, and the effective inductance can be reduced by a small margin, while the thickness of the embedded glass substrate inductor prepared by glass reflux process can be as high as hundreds of microns. The practical application value of the process and the design idea is verified. High doped silicon is not suitable for practical production because of its high loss and low quality factor. Copper as inductor has excellent electromagnetic properties. Inductors with different structure have different quality factors, effective inductors and frequencies. With the increase of the thickness, the increase rate of the inductance quality factor decreases, and when the thickness reaches a certain thickness, there exists the phenomenon of the quality factor rolling down, while the effective inductor continues to decrease slowly, so the action range of the thickness is not infinite. Finally, this paper summarizes the design, experiment and simulation, and puts forward new research ideas.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN405

【相似文献】