The High‐temperature Wettability and Crystallization of Blended Glass Determine the Sintering of Dielectric Paste

ABSTRACT The dielectric layer in thick‐film dielectric paste acts as an insulating barrier between the conductor and the substrate, and also affects the degree of densification during the sintering process, thereby directly determining the stability and reliability of the device. This study has proposed a technical approach for blending two Ca‐Al‐Si glass systems with high and low melting points, which aims to enhance the comprehensive performance of the dielectric layer through the complementary properties of the two glasses. By comparing the differences between single‐glass and composite‐glass formulations in terms of structure, thermal properties, crystallization behavior, and high‐temperature wettability, this study has investigated the impact of these factors on the dielectric layer during the sintering process. The results indicated that when the ratio of mixed glass frits was 1:1, the wettability with the stainless steel substrate was better at high temperatures. And the maximum volume shrinkage rate (48.41%) was reached during the sintering process. This was primarily attributed to the low‐melting‐point glass softening and spreading first at medium temperatures, which effectively improved the wettability of the glass on the stainless steel substrate. High‐melting‐point glass maintains the structural framework at high temperatures, preventing excessive flow and shrinkage, and delaying excessive crystallization. The two types of glass fill the pores and promote the densification of the dielectric layer, while exhibiting appropriate crystallization behavior to ensure the impact resistance and stability of the dielectric layer. Ultimately, the electrical performance parameters, such as the insulation resistance and breakdown voltage of the dielectric layer, were improved.