薄膜金属化LTCC基板的薄膜阻碍层对共晶焊的影响

讨论了LTCC工在板薄膜金属化技术中,有效阻碍层的选择对基板共晶焊的影响。实验结果表明,Ti/Ni是一种高可靠性的阻碍层,而且Ti/Ni/Au也是一种较理想的LTCC基板薄膜金属化结构。     

基于LTCC基板BCB/Cu薄膜混合多层互连技术研究

针对微系统小型化集成对高性能成膜基板需求,研究了基于LTCC基板的BCB/Cu薄膜多层互连关键技术及过程控制要求。提出一种高可靠"T"型界面互连方式的薄膜磁控溅射Cr/Cu/Cr和Cr/Pd/Au复合膜层结构及其制备方法。研究了LTCC基板收缩率偏差、LTCC-薄膜界面缺陷及粗糙度、BCB介质膜固化应力、介质膜金属化的应力等因素对厚薄膜混合基板质量的影响。制备的12层厚薄膜混合基板(10层LTCC基板,2层薄膜布线) 60片,100%全部通过GJB2438 C.2.7成膜基片评价考核要求,相比LTCC基板,布线密度提高4倍,尺寸缩小40%。     

LTCC工艺技术研究

叙述了LTCC技术的起源、特点及未来发展趋势.介绍了LTCC产品的种类、优越性及广阔的应用领域,对LTCC工艺技术中高精度金属化印刷技术和陶瓷高温共烧技术进行了深入研究,剖析了影响金属化印刷精度、导体表面粗糙度、LTCC基板翘曲度和陶瓷强度的工艺因素.并分析了如何根据产品布线特点来设计和优化印刷工艺参数、如何根据基板结构特点来设计和优化排胶曲线.通过大量的工艺试验和数据测试,结果表明,印刷压力影响金属化导体精度和表面粗糙度、烧结曲线排胶段升温速率影响LTCC基板翘曲度和陶瓷强度.     

LTCC基板上薄膜多层布线工艺技术

LTCC基板上薄膜多层布线工艺是MCM-C/D多芯片组件的关键技术。它可以充分利用LTCC布线层数多、可实现无源元件埋置于基板内层、薄膜细线条等优点,从而使芯片等元器件能够在基板上更加有效地实现高密度的组装互连。文章介绍了LTCC基板上薄膜多层布线工艺技术,通过对导带形成技术、通孔柱形成技术和聚酰亚胺介质膜技术的研究,解决了在LTCC基板上薄膜多层布线中介质膜"龟裂",通孔接触电阻大、断路,对导带的保护以及电镀前的基片处理等工艺难题。     

一种LTCC基板上薄膜多层布线技术

LTCC基板上薄膜多层布线工艺是MCM—C／D多芯片组件的关键技术,它可以充分利用LTCC布线层数多、可实现无源元件埋置于基板内层、薄膜细线条精确等优点,从而使芯片等元器件能够在基板上更加有效地实现高密度的组装互连。本文介绍了在LTCC基板上薄膜多层布线工艺技术,通过对导带形成技术、通孔柱形成技术和聚酰亚胺介质膜技术的研究,解决了在LTCC基板上薄膜多层布线的工艺难题。     

薄膜金属化低温共烧陶瓷基板的阻碍层对共晶焊的影响

讨论了低温共烧陶瓷基板薄膜金属化技术中,有效阻碍层的选择对基板共晶焊的剪切强度、互连阻抗、可焊性的影响。试验结果表明,Ti / Ni是一种高可靠性的阻碍层,且Ti / Ni / Au也是一种较理想的低温共烧陶瓷基板薄膜金属化结构。     

低温共烧陶瓷多层基板精细互连技术

微电子技术和封装工艺的发展使超大规模集成电路(VLSI)的密度越来越高,而高密度低温共烧陶瓷(LTCC)基板的制作依赖于基板内部导体的精细互连技术.为了满足LTCC多层基板高密度互连的工艺要求,必须使基板微通孔的直径及导线线宽缩小到100 μm以内.基于此,首先介绍了LTCC生瓷带层的微通孔形成与填充工艺,以及所形成的微通孔的特点;利用厚膜丝网印刷技术形成精细导线,分析了影响印刷质量的工艺参数;最后简要介绍了薄膜光刻等新技术.通过应用上述几种先进的精细互连工艺技术,极大地提高了LTCC多层基板的互连密度.     

基于BCB的薄膜多层基板在毫米波T/R组件中的应用

基于BCB的薄膜多层基板具有优异的高频特性,是毫米波频段多芯片组件集成封装的重要途径。研究了BCB薄膜多层基板在Ka波段相控阵雷达T/R组件中应用的可行性,首先与LTCC基板对比验证了BCB微带线的传输特性,然后研制了功率分配/合成器、穿墙过渡等关键微波无源电路,最后设计了八通道的无源组件进行微波性能测试评估,结果表明基于BCB的薄膜多层基板能够满足应用需要。     

基于LTCC基板的薄膜微带线制作技术

本文对厚、薄膜多层互连基板的发展进行了简单的分析，对基于LTCC基板的薄膜50Ω微带线的设计、制造、测试进行了介绍。结果表明LTCC基板表面实施薄膜工艺与厚膜工艺相比有利于获得更好的微波一致性。     

LTCC表面金属化的可焊性研究

采用还原气氛焊接,研究了LTCC基板的表面金属化工艺对In-Sn、Pb-Sn和Au-Sn焊料可焊性的影响。结果表明厚膜烧结的PdAg导体可焊性较差,In-Sn和Pb-Sn焊料在其表面分别出现了不润湿和溶蚀现象。通过对LTCC基板表面导体进行电镀改性,Cu/Ni/Au镀层提高了Pb-Sn和Au-Sn焊料的可焊性,而Cu/Ni/Sn镀层则提高了In-Sn和Pb-Sn焊料的可焊性。最后,对提高可焊性的因素进行了讨论。     

大尺寸LTCC焊接组件热变形特性的仿真研究

为了研究不同封装条件对低温共烧陶瓷(LTCC)基板封装焊接后残余热应力的影响,该文针对不同温变载荷下LTCC基板的热应力变形进行了仿真计算和实验测试,结果显示仿真计算与实验测试结果具有较好的一致性,验证了数值仿真用于LTCC基板封装焊接后残余热应力仿真的可行性。在此基础上对零膨胀合金底板和硅铝合金封装条件下3种典型工作温度对应的LTCC基板的热应力进行了仿真计算。结果表明,封装焊接后LTCC基板两侧边缘应力集中,中间残余应力小,呈翘曲状态,采用硅铝合金封装焊接的热应力小于零膨胀合金封装。     

混合导体LTCC基板可靠性研究

从混合导体LTCC基板的微观结构,导体的附着力,导体键合强度,多层互连导带电阻以及基板绝缘电阻等方面,对混合导体LTCC基板的可靠性进行了分析研究。结果表明:基板内部的银导体不存在迁移现象,导体的附着力、键合强度以及基板的绝缘电阻等性能均比较理想。     

LTCC基板共烧平整度工艺研究

LTCC共烧工艺是基板加工的重要环节,有很多因素会影响产品加工进程。一般来说,从设计上要预先充分考虑,以避免负面因素影响基板共烧效果。介绍了LTCC基板/低温共烧陶瓷基板技术及共烧致密化技术的机理,阐述了LTCC平整度重要性及改善基板表面平整度工艺的优化过程。通过综合比较版图优化前后的内层金属含量、不同尺寸样品加工、结构设计等因素,经过多重试验验证,结果表明,版图优化措施切实可行,可有效提高LTCC基板共烧平整度。     

On sputtered thin-films of chrome,nitrided chrome and nickel-chromium

Sputter deposited thin-film chromium, chromium-nitride and nickel-chromium have been evaluated for use in resistor fabrication. Some of the data obtained is qualitatively similar to that obtained in thin-film investigation, however, from a practical point of view the data contained herein is of a quantitative nature and might prove useful to those involved in thin-film resistor manufacture (results were obtained on a commercially available system). Relatively little data has been reported on reactively sputtered chromium in argon/nitrogen mixtures. The data presented here indicate that although not suitable for resistor fabrication, reactively sputtered chrome may be useful as thin-film thermistors.     

Terahertz MMICs and Antenna-in-Package Technology at 300 GHz for KIOSK Download System

Toward the realization of ultra-fast wireless communications systems, the inherent broad bandwidth of the terahertz (THz) band is attracting attention, especially for short-range instant download applications. In this paper, we present our recent progress on InP-based THz MMICs and packaging techniques based on low-temperature co-fibered ceramic (LTCC) technology. The transmitter MMICs are based on 80-nm InP-based high electron mobility transistors (HEMTs). Using the transmitter packaged in an E-plane split-block waveguide and compact lens receiver packaged in LTCC multilayered substrates, we tested wireless data transmission up to 27 Gbps with the simple amplitude key shifting (ASK) modulation scheme. We also present several THz antenna-in-packaging solutions based on substrate integrated waveguide (SIW) technology. A vertical hollow (VH) SIW was applied to a compact medium-gain SIW antenna and low-loss interconnection integrated in LTCC multi-layer substrates. The size of the LTCC antennas with 15-dBi gain is less than 0.1 cm³. For feeding the antenna, we investigated an LTCC-integrated transition and polyimide transition to LTCC VH SIWs. These transitions exhibit around 1-dB estimated loss at 300 GHz and more than 35 GHz bandwidth with 10-dB return loss. The proposed package solutions make antennas and interconnections easy to integrate in a compact LTCC package with an MMIC chip for practical applications.     

A Cr—Ag—Au metalization system

A comprehensive study of a Cr-Ag-Au metalization system, as well as a comparison with an aluminum system, is described. The Cr-Ag-Au metalization system, which can be deposited in a conventional evaporator with relatively little increase in processing complexity, has the desirable characteristics of aluminum metalization. It can be patterned more easily than equivalent thicknesses of aluminum. The Cr-Ag-Au has excellent storage characteristics at 300°C and has a much longer mean time to failure than does aluminum under high current density-high temperature stress. In addition, measurements show that with the use of an enhancement diffusion the Cr-Ag-Au produces as good as or better contact to p- and n-type silicon than does aluminum. Finally, the absence of significant metalization-oxide interaction makes Cr-Ag-Au useful for MOS devices and the ease with which contact is made between layers of this metalization indicates a number of applications for Cr-Ag-Au in multilayered devices.     

High-Tc superconducting coplanar waveguidefilter

Coplanar waveguide (CPW) low-pass filters made of YBa₂Cu₃O_7-δ (YBCO) on LaAlO₃ substrates, with dimensions suited for integrated circuits, were fabricated and packaged. A complete filter gives a true idea of the advantages and difficulties in replacing thin-film metal with a high-temperature superconductor in a practical circuit. Measured insertion losses in liquid nitrogen were superior to the loss of a similar thin-film copper filter throughout the 0- to 9.5-GHz passband. These results demonstrate the performance of fully patterned YBCO in a practical CPW structure after sealing in a hermetic package