The effects of substrate composition on thick film circuit reliability
Abstract
The saturation solubility of AlSiMag 614 (96% Al2O3) substrates in thick film resistor glass was determined as a function of temperature. These results were combined with dissolution rate studies in order to test various kinetic models. The viscosity of the resistor glass was measured as a function of amount of dissolved AlSiMag 614 substrate from the softening point to the annealing point of the glasses. The isothermal viscosity was found to increase by a factor of 20 with 10 w/o dissolved substrate relative to the standard lead borosilicate glass. The affects of the minor constitutients (4%) in the AlSiMag 614 substrate composition on viscosity and surface tension of the glasses was determined to be small. The sheet resistance, temperature dependence of resistance, and the current noise were measured for thick film resistors as a function of the amount of substrate dissolved in the resistor for various firing temperatures at constant firing time, and for various firing times at 800 C. Large variations in these three properties were observed, and the changes were qualitatively correlated with changes in viscosity of the glass. The microstructure development and charge transport models used to correlate the results indicate a retardation of microstructure development in the resistors as the amount of dissolved substrate increases.
- Publication:
-
Final Report
- Pub Date:
- February 1979
- Bibcode:
- 1979puwl.reptQ....V
- Keywords:
-
- Ceramics;
- Circuit Reliability;
- Resistors;
- Solid Solutions;
- Solubility;
- Thick Films;
- Aluminum Oxides;
- Electrical Resistivity;
- Magnesium Compounds;
- Temperature Gradients;
- Viscosity;
- Electronics and Electrical Engineering