Mechanism study of femtosecond laser induced selective metallization (FLISM) on glass surfaces

We investigate the mechanism of selective metallization on glass surfaces with the assistance of femtosecond laser irradiation followed by electroless plating. Irradiation of femtosecond laser makes it possible to selectively deposit copper microstructures in the irradiated area on glass surfaces coated with silver nitrate films. The energy-dispersive X-ray (EDX) analyses reveal that silver atoms are produced on the surface of grooves formed by laser ablation, which serve as catalysis seeds for subsequent electroless copper plating.     

多次金属化烧结的初步探讨

通过二/三次金属化烧结实验,对提高陶瓷金属化质量进行初步探讨.     

Interest of NH3 and N2 plasmas for polymer surface treatment before “electroless” metallization

The electroless metallization of polymers needs an activation of their surface which consists of palladium chemisorption. In this study, the effect of surface treatments of polystyrene and polyamide substrates by reactive gas plasmas (O₂, NH₃, N₂) has been followed by XPS analysis. According to the functional groups grafted on the surface, specific chemisorption reactions can occur. The latter have been highlighted through a comparative investigation of two activation processes, viz. a conventional way using successively SnCl₂ and PdCl₂ solutions and a new procedure, developed by the authors, using only a PdCl₂ solution. This work shows that this simplified process can be extended to any polymer whose surface is grafted with nitrogenated functions.     

Effect of substrate metallization on interfacial reactions and reliability of Sn-Zn-Bi solder joints

The scope of this paper covers a comprehensive study of the lead-free Sn-Zn-Bi solder system, on Cu, electrolytic Ni/Au and electroless Ni(P)/Au surface finishes. This includes a study of the shear properties, intermetallic compounds at the substrate-ball interface and dissolution of the under bump metallization. The Sn-8Zn-3Bi (wt.%) solder/Cu system exhibited a low shear load with thick IMCs formation at the interface. The dissolution of the Cu layer in the Sn-Zn-3Bi solder is higher than that of the other two Ni metallizations. It was found that the formation of a thick Ni-Zn intermetallic compound (IMC) layer at the solder interface of the electrolytic Ni bond pad reduced the mechanical strength of the joints during high temperature long time liquid state annealing. The solder ball shear-load for the Ni(P) system during extended reflow increased with an increase of reflow time. No spalling was noticed at the interface of the Sn-Zn-3Bi solder/Ni(P) system. Sn-8Zn-3Bi solder with electroless Ni(P) metallization appeared as a good combination in soldering technology.     

陶瓷四边引线扁平外壳工艺研究

陶瓷四边引线扁平外壳具有体积小、重量轻、封装密度高、热电性能好、适合表面安装的特点,可广泛用于各种大规模集成电路封装,如ECL及CMOS门阵列电路等。文中叙述了CQFP陶瓷四边引线扁平外壳工艺研究中的关键工艺技术,如：金属浆料的配制工艺技术、大版精细印刷工艺技术、大腔体层压工艺技术、细引线拉力强度工艺技术等,以及今后努力的方向。     

高密度互连印制电路板孔金属化研究和进展

孔金属化互连是印制电路板(PCB)高密度集成的核心制程之一,化学镀铜和电子电镀铜是实现孔金属化的关键技术.本文介绍HDI-PCB的概念和制作流程;综述化学镀铜和电子电镀铜孔金属化互连的研究和进展,包括溶液组成和操作条件的影响,添加剂及其相互作用机理,以及盲孔填充和通孔孔壁加厚机制;展望高密度互连印制电路板电子电镀基础研...     

Electromigration study in SnAg3.8Cu0.7 solder joints on Ti/Cr-Cu/Cu under-bump metallization

This paper investigates the electromigration-induced failures of SnAg3.8Cu0.7 flip-chip solder joints. An under-bump metallization (UBM) of a Ti/Cr-Cu/Cu trilayer was deposited on the chip side, and a Cu/Ni(P)/Au pad was deposited on the BT board side. Electromigration damages were observed in the bumps under a current density of 2×10⁴ A/cm² and 1×10⁴ A/cm² at 100°C and 150°C. The failures were found to be at the cathode/chip side, and the current crowding effect played an important role in the failures. Copper atoms were found to move in the direction of the electron flow to form intermetallic compounds (IMCs) at the interface of solder and pad metallization as a result of current stressing.     

Effects of substrate metallization of solder/under-bump metallization interfacial reactions in flip-chip packages during multiple reflow cycles

The effects of various elements of substrate metallization, namely, Au, Ni, and P, on the solder/under-bump metallization (UBM), (Al/Ni(V)/Cu) interfacial reactions in flip-chip packages during multiple reflow processes were systematically investigated. It was found that Au and P had negligible effects on the liquid-solid interfacial reactions. However, Ni in the substrate metallization greatly accelerated the interfacial reactions at chip side and degraded the thermal stability of the UBM through formation of a (Cu,Ni)₆Sn₅ ternary compound at the solder/UBM interface. This phenomenon can be explained in terms of enhanced grain-boundary grooving on (Cu,Ni)₆Sn₅ in the molten solder during the reflow process. This could eventually cause the rapid spalling of an intermetallic compound (IMC) from the solder/UBM interface and early failure of the packages. Our results showed that formation of multicomponent intermetallics, such as (Cu,Ni)₆Sn₅ or (Ni,Cu)₃Sn₄, at the solder/UBM interface is detrimental to the solder-joint reliability.     

针封封接技术的再探讨

为提高针封封接质量,在改进金属化膏剂、金属化烧结方式、涂膏方法、封接工艺等方面进行探讨.     

低价位生产特陶材料和经济金属化技术

叙述了低价生产特陶材料和经济金属化的重要性和生产技术，主要包括高压绝缘子瓷，低含量Al2O3瓷以及经济金属化技术等，文中对纳米金属化技术的前景也作了某些评价。