This work aims to fabricate a large-area ceramic substrate for the application of probe cards.
Mullite (M) and cordierite (C), which both have a low thermal expansion coefficient, excellent resistance to thermal
shock, and high durability, were selected as starting powders. The
mullite-cordierite composites were produced through different composition ratios of starting powders (M:C = 100:0, M:C = 90:10, M:C = 70:30, M:C = 50:50, M:C = 30:70, and M:C = 0:100). The effects of composition ratio and sintering temperature on the density, porosity, thermal expansion coefficient, and flexural strength of the
mullite-cordierite composite pellets were investigated. The results showed that the
mullite-cordierite composite pellet containing 70 wt%
mullite and 30 wt% cordierite sintered at 1350 °C performed exceptionally well. Based on these findings, a large-area
mullite-cordierite composite substrate with a diameter of 320 mm for use in
semiconductor probe cards was successfully fabricated. Additionally, the changes in sheet resistance and flexural strength were measured to determine the effect of the environmental tests on the large-area substrate such as damp heat and thermal
shock. The results indicated that the
mullite-cordierite composite substrate was extremely reliable and durable.