Stability Observations and Surface Analysis of Air Fired Nickel Thick Film Conductors

The results from an investigation of the properties of air fired Nickel thick film produced with conductive paste ESL 2554 on 96% Al2O3 substrates are described. The analysis of the possible causes of instability of this thick film material has been done using the methods of surface analysis. The picture of the film surface structure obtained as a result of surface analysis shows a non-isotropic distribution of the metal and glass phase. For a firing peak temperature of 650℃ there is little nickel present at the film surface, and this could be the main cause of the high instability and low adhesion observed. To obtain a stable film the maximum firing peak temperature has been established at 580℃. This has been confirmed by comparing the surface analysis results from films prepared at 650℃ and 580℃ peak temperatures.