Extended Temperature Cycling of Plastic and Ceramic I/C´s with Thermal Shock Preconditioning

The purpose of this investigation was to determine if liquid-liquid thermal shock preconditioning would affect subsequent longterm temperature cycling performance of ceramic and/or plastic dual-in-line packaged devices or ceramic or metal flat packages. Three levels of preconditioning were investigated, each followed by three levels of temperature cycling to form a 3×3 balanced matrix, analyzed by an Analysis of Variance. Fifteen cycles of preconditioning were used (as required to process Class A 38510 parts), followed by up to 3,000 cycles of temperature cycling. This investigation showed that there was no significant thermal-shock/temperature cycling interactions, but that a wide range of life response was observed between and within package types. This experiment increases our knowledge of device behavior when subjected to extended temperature cycling and allows, direct comparisons between plastic and ceramic dual-in-line packages. End of life was observed for several of the samples. The results indicated that there was no significant interaction between the levels of preconditioning used and the subsequent extended temperature cycling used, regardless of package type or material used. For DC electrical failures, there was no independent effect due to temperature cycling, nor independent effect due to thermal shock preconditioning for any of the package types. There was a very strong independent effect due to thermal shock with respect to both indicated and confirmed fine leak failures within the black ceramic dual-in-line packages only. The white ceramic sidebraze package passed all leak testing without a single hermeticity failure.