We investigated the interaction between screen printed and fired layers consisting of either PbO or Bi2O3 and ceramic substrates: alluminia and berylia; It was found that PbO interacts with aluminia via two main processes viz. a reaction between PbO and Al2O3 grains which induces the formation of Pb2Al2O5, and an interdiffusion process involving Pb and the intergranular amorphous phase in the substrate. Until PbO is not exhausted, the penetration depth of Pb in the ceramic is diffusion limited with an activation energy of 1.20 ± 0.05 e V. Berylia exhibit similar effects but no Be-bearing compound was observed. Very different results were found with Bi2O3 layers, where the reaction products are invariably crystalline in nature: e.g. Bi2O3 polymorphic phases (BeO substrates), Al4Bi2O9 (99%-alumina), Bi12SiO20(96%-alumina)
Interactions between bismuth oxide and ceramic substrates for thick film technology
Bersani, Massimo
1998-01-01
Abstract
We investigated the interaction between screen printed and fired layers consisting of either PbO or Bi2O3 and ceramic substrates: alluminia and berylia; It was found that PbO interacts with aluminia via two main processes viz. a reaction between PbO and Al2O3 grains which induces the formation of Pb2Al2O5, and an interdiffusion process involving Pb and the intergranular amorphous phase in the substrate. Until PbO is not exhausted, the penetration depth of Pb in the ceramic is diffusion limited with an activation energy of 1.20 ± 0.05 e V. Berylia exhibit similar effects but no Be-bearing compound was observed. Very different results were found with Bi2O3 layers, where the reaction products are invariably crystalline in nature: e.g. Bi2O3 polymorphic phases (BeO substrates), Al4Bi2O9 (99%-alumina), Bi12SiO20(96%-alumina)I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
