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Laser ablation of thin films on LTCC

Proceedings - 2014 47th International Symposium on Microelectronics, IMAPS 2014

Girardi, M.A.; Peterson, K.A.; Vianco, Paul T.; Grondin, R.; Wieliczka, D.

Direct Digital Manufacturing techniques such as laser ablation are proposed for the fabrication of lower cost, miniaturized, and lightweight integrated assemblies with high performance requirements. This paper investigates the laser ablation of a Ti/Cu/Pt/Au thin film metal stack on fired low temperature cofired ceramic (LTCC) surfaces using a 355 nm Nd.YAG diode pumped laser ablation system. It further investigates laser ablation applications using unfil ed, or 'green', LTCC materials: (1) through one layer of a laminated stack of unfiled LTCC tape to a buried thick film conductor ground plane, and (2) in unfiled Au thick films. The UV laser power profile and part fixturing were optimized to address defects such as LTCC microcracking, thin film adhesion failures, and redeposition of Cu and Pt. An alternate design approach to minimize ablation time was tested for efficiency in manufacture. Multichip Modules (MCM) were tested for solder ability', solder leach resistance, and wire bondabilify. Scanning election microscopy (SEM) as well as cross sections and microanalytical techniques were used in this study.

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TYPE Conference Poster YEAR 2014
ScopusOSTIDOI

Accelerated aging of Sn-Pb and Pb-free solder joints on hybrid microcircuit assemblies

IBSC 2012 - Proceedings of the 5th International Brazing and Soldering Conference

Vianco, Paul T.; Kilgo, Alice C.; Wroblewski, Brian W.; Zender, Gary L.; Guerrero, E.

The development of Pb-free solutions for the highreliability electronics community necessitates the consideration of hybrid microcircuit (HMC) products. This study used a test vehicle that included both plastic and ceramic packages as well as leaded and area-array solder joints on an alumina substrate. The conductor was a Ag-Pd thick film layer. The shear strength was measured for interconnections made with 63Sn-37Pb (wt.%, abbreviated Sn-Pb) and 95.5Sn-3.0Ag-0.5Cu (Sn-Ag-Cu) solders as a function of isothermal aging, thermal cycling, and thermal shock environments. The area-array packages indicated that solder joint fatigue was not altered significantly in a forward compatibility situation (i.e., Sn-Pb balls and a Sn-Ag-Cu assembly process). Local CTE mismatch fatigue strains are important for solder joints connecting ceramic area array packages to ceramic substrates. The gull-wing lead, SOT plastic package solder joints assembled with the Sn-Ag-Cu solder exhibit a greater strength loss under temperature cycling than did the corresponding Sn-Pb interconnections. Thermal shock is more detrimental to Sn-Pb HMC solder joints than are the equivalent number of thermal cycles. Copyright 2012 ASM International® All rights reserved.

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TYPE Conference YEAR 2012
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Results 51–75 of 171
Results 51–75 of 171