Analysis of mechanical properties of LTCC substrates

Abstract

In this paper we describe the most commonly used methods for analysis the mechanical properties of 3 types LTCC substrates (DuPont 951, DuPont 9K7, MuRata) based on three- and four-point bending as well as Dynamic Mechanical Analysis (DMA). The results of analysis show that the four-point bend test indicates a distribution of stress in the substrate with more accuracy and points to the tendency of the fracture-toughness state in the material. The three-point bend test achieves higher flexural strength of tested substrates. The re-firing process applied to the LTCC type 951 increases the flexural strength by 10 %. Extension of the duration of the firing process from 4 h to 26.5 h causes increasing the flexural strength by 100 %. This work proves that the Murata has the best homogeneity and the LTCC type 9K7 has the greatest predisposition to brittle fracture at a distance of lower supports of 32 mm. The sintering process' conditions of the ceramics have the significant influence to the shrinkage of the all tested ceramics' types. DMA analyses of the ceramics within the elasticity range confirm the described behavior of fracture-toughness state realized by classic test methods.