TABLE OF CONTENTS Soldering & Surface Mount Technology
16/2 [2004] 3 4
Abstracts & keywords
Emerald Group Publishing Limited
[ISSN 0954 0911]
W.J.Plumbridge
Keywords Reliability, Reliability management, Solders, Modelling
The decision to move to lead-free solders has been made, but processing and performance challenges remain. This paper considers the transition in terms of performance, with particular emphasis on long term, high reliability applications. Comparison of key mechanical properties indicates generally beneficial outcomes of the transition to lead-free alloys, although there is a lack of understanding surrounding^ anomalous observations, such as the effects of the bismuth. The lower melting point of Sn-Zn-Bi alloys, together with their comparable mechanical properties, provide further impetus to address their shortcomings during processing. Some lead-free alloys, such as Sn-0.5Cu, are susceptible to tin-pest formation following prolonged exposure below 13 C, and this possibility remains for the more concentrated Sn-3.8Ag-0.7Cu alloy.
Eric C.C.Yan, S.W.Ricky Lee and X.Huang
Keywords Product reliability, Solders, Shear strength, Semiconductor technology
This paper presents an experimental study to assess the reliability of solder ball attachment to the bond pads of PBGA substrate for various plating schemes. The basic structure of the under bump metallisation is Cu/Ni/Au. Three different kinds of electroless plating solutions are used to deposit the Ni layer, namely, Ni-B, Ni-P (5 per cent), and Ni-P (10 per cent). Also, conventional electrolytic Ni/Au plating is performed to provide a...
