Structure and properties of low-melting Bi2O3-B2O3-MnO-CuO glasses for conductive silver paste

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2023-11, Vol.129 (11), Article 810
• Main Authors: He, Longqing, Luo, Zhiwei, Liang, Haozhang, Ma, Nanshan, Liu, Xinyu, Zhou, Ziyou, Lu, Anxian
• Format: Article
• Language: English
• Subjects: Applied physics; Bismuth trioxide; Boron oxides; Characterization and Evaluation of Materials; Condensed Matter Physics; Dissolution; Glass transition temperature; Lead free; Machines; Manganese oxides; Manufacturing; Materials science; Molar volume; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Silicon substrates; Silver; Surfaces and Interfaces; Thermal expansion; Thin Films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-023-07087-x

In this work, the 30Bi 2 O 3 -38B 2 O 3 -3SiO 2 -5Al 2 O 3 -(24-x)MnO-xCuO (x = 6, 10, 14, 18, 22 mol%) lead-free bismuth borate glasses were prepared by the melt-quenching method. The effects of CuO substitution for MnO on the structure and properties of the bismuth borate glass were investigated. As the CuO content increases from 6 to 22 mol%, the density of the glass gradually increases while the molar volume shows an opposite trend. The FTIR spectra show that [BiO 3 ], [BiO 6 ], [BO 3 ], and [BO 4 ] are the main structural units in the bismuth borate glass network. The vibrations of both [BiO 3 ] and [BO 4 ] units are enhanced with the increasing CuO content. With the increase of CuO content, the glass transition temperature ( T g ) decreases from 438 to 417 ℃ and the softening temperature ( T f ) decreases from 470 to 452 ℃. The thermal expansion coefficient ( CTE ) decreases from 7.875 to 7.702 × 10 –6 /℃ in the temperature range of 30–300 ℃, which is between the thermal expansion coefficients of Ag (19 × 10 –6 /℃) and silicon substrates (2.5 × 10 –6 /℃). In addition, the HF resistance of the bismuth borate glasses gradually improves as the CuO content increases, with a minimum dissolution rate of 14.27 × 10 –3  g cm −2  min −1 . The NaOH resistance of the bismuth borate glasses initially decreases and then remains stable, with a maximum dissolution rate of 14.66 × 10 –3  g cm −2  min −1 . The results revealed that the investigated Bi 2 O 3 -B 2 O 3 -MnO-CuO glass can be used as a suitable alternative to lead-based glass for conductive silver paste.