John Lau, Dongkai Shangguan, Todd Castello, Rob Horsley, Joe Smetana, Nick Hoo, Walter Dauksher, Dave Love, Irv Menis and Bob Sullivan
Failure analyses of the lead‐free and SnPb solder joints of high‐density packages such as the plastic ball grid array and the ceramic column grid array soldered on SnCu hot‐air…
Abstract
Failure analyses of the lead‐free and SnPb solder joints of high‐density packages such as the plastic ball grid array and the ceramic column grid array soldered on SnCu hot‐air solder levelling electroless nickel‐immersion gold or NiAu, and organic solderability preservative Entek printed circuit boards are presented. Emphasis is placed on determining the failure locations, failure modes, and intermetallic compound composition for these high‐density packages' solder joints after they have been through 7,500 cycles of temperature cycling. The present results will be compared with those obtained from temperature cycling and finite element analysis.
Details
Keywords
John Lau, Walter Dauksher, Joe Smetana, Rob Horsley, Dongkai Shangguan, Todd Castello, Irv Menis, Dave Love and Bob Sullivan
The lead‐free solder joint reliability of several printed circuit board mounted high‐density packages, when subjected to temperature cycling was investigated by finite element…
Abstract
The lead‐free solder joint reliability of several printed circuit board mounted high‐density packages, when subjected to temperature cycling was investigated by finite element modelling. The packages were a 256‐pin plastic ball grid array (PBGA), a 388‐pin PBGA, and a 1657‐pin ceramic column grid array. Emphasis was placed on the determination of the creep responses (e.g. stress, strain, and strain energy density) of the lead‐free solder joints of these packages.
Details
Keywords
John Lau, Nick Hoo, Rob Horsley, Joe Smetana, Dongkai Shangguan, Walter Dauksher, Dave Love, Irv Menis and Bob Sullivan
Temperature cycling tests, and statistical analysis of the results, for various high‐density packages on printed‐circuit boards with Sn‐Cu hot‐air solder levelling, electroless…
Abstract
Temperature cycling tests, and statistical analysis of the results, for various high‐density packages on printed‐circuit boards with Sn‐Cu hot‐air solder levelling, electroless nickel‐immersion gold, and organic solder preservative finishes are investigated in this study. Emphasis is placed on the determination of the life distribution and reliability of the lead‐free solder joints of these high‐density package assemblies while they are subjected to temperature cycling conditions. A data acquisition system, the relevant failure criterion, and the data extraction method will be presented and examined. The life test data are best fitted to the Weibull distribution. Also, the sample mean, population mean, sample characteristic life, true characteristic life, sample Weibull slope, and true Weibull slope for some of the high‐density packages are provided and discussed. Furthermore, the relationship between the reliability and the confidence limits for a life distribution is established. Finally, the confidence levels for comparing the quality (mean life) of lead‐free solder joints of high‐density packages are determined.
Details
Keywords
Joe Smetana, Rob Horsley, John Lau, Ken Snowdon, Dongkai Shangguan, Jerry Gleason, Irv Memis, Dave Love, Walter Dauksher and Bob Sullivan
The High Density Packaging Users Group conducted a substantial study of the solder joint reliability of high‐density packages using lead‐free solder. The design, material, and…
Abstract
The High Density Packaging Users Group conducted a substantial study of the solder joint reliability of high‐density packages using lead‐free solder. The design, material, and assembly process aspects of the project are addressed in this paper. The components studied include many surface mount technology package types, various lead, and printed circuit board finishes and paste‐in‐hole assembly.
Details
Keywords
Abstract
Details
Keywords
I don’t remember exactly when I began to be interested in music, but my mother and godmother would laughingly recall when they knew I would be musically inclined. Though I was…
Abstract
I don’t remember exactly when I began to be interested in music, but my mother and godmother would laughingly recall when they knew I would be musically inclined. Though I was then in diapers, whenever Tommy Dorsey's recording of Boogie Woogie was played, I would immediately begin to pat my feet. My first conscious memory of reacting to music when I was very young were the times my father would sing little ditties and play his banjo. He could carry a tune, and he played the banjo quite well. His greatest musical feat, however, was as a whistler, and I would try to imitate his whistling style, without success as I grew older. Then too, my siblings and I would sing and recite little nursery rhymes before our parents, and I would compose songs for my sisters to sing. Before he died an early death at 37 my father gave me a mouth harp and a harmonica which I kept for many years; I later misplaced it while in college. I later bought another harmonica which I kept throughout my years in the U.S. Army, my travels throughout Europe, and throughout my years in graduate school. How and why we each possess the talents and skills we have are questions I’ve never fully understood. So I’ve concluded that we just have them, and we’ll never be able to explain it. Throughout this chapter four reference points will be used to explain my exposure to music and my music biculturality: schools, churches, home, and my neighborhood. If I make very few references to whites, it is simply because during my early life my contact with whites was minimal, and white individuals played a minor role in my life, as at home my world centered around my parents and godparents, siblings, and other family members, and neighborhood friends; at school my world was a completely black world. The first white I got to know outside of my early work experiences was the white Presiding Bishop of the Reformed Episcopal Church who visited St. John's Episcopal Church at least six or seven times a year.