CHEMICAL DURABILITY OF LEAD-OXIDE-BASED, THICK-FILM BINDER CLASSES

Lead-oxide-bearing glasses are incompatible with aluminum nitride meta llizations, and federal legislation is recommending their replacement in thick-film electronics and labeling. To evaluate alternatives, the benchmark chemical durabilities of the lead borosilicate and lead alum inate thick-film binder glasses have been determined. Aluminum oxide ( Al2O3) benefits water durability moderately, acid durability substanti ally, and basic durability indistinguishably. The rate of attack in wa ter is approximately two orders of magnitude greater than for soda-lim e glass. The thermal contractions of the glasses are compatible. An ap parent, spontaneous phase separation in the Al2O3-free glass is suppre ssed by Al2O3 that is included as a batch component.