Fabrication and characterization of nickel-gold plateble LTCC substrates based on borosilicate glass/Al 2 O 3 system

Borosilicate glass with the additions of Al 2 O 3 (40~55%) composites were sintered at 850°C. Different qualitative and quantitative instruments were used to employ the influence mechanism of the different Al 2 O 3 contents on the properties of the composites. Composites with 45wt% Al 2 O 3 sintered at 850°C presented great performance: the bulk density of 2.51 g/cm 3 , the dielectric constant of 5.27 and the dielectric loss of 0.0027 at 1 MHz, the thermal expansion coefficient of 5.79*10 −6 ppm/°C, the flexural strength of 142.5MPa and the weight loss of 2.78 mg/cm 2 after soaking in 1 mol/L nitric acid Solution. The composite could meet the shrinkage requirement of Ag electrodes and could not possibly react with Ag electrodes any more. The metallized substrate can withstand the electroless nickel immersion gold process.