1. Chipping-induced fracture investigation of glass interposer with dielectric coatings.
- Author
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Lee, Chang-Chun, Chuang, Jui-Chang, Lee, Chien-Han, and Cheng, Hsien-Chie
- Abstract
In wafer dicing operations, several chipping effects involving breakage or micro-cracks were often observed along the cut line of the glass interposer, mainly due to its brittle and hard material characteristics. When the interposer is further subjected to thermal loading in the subsequent packaging process and environmental stressing conditions, these micro-cracks or breakages may continue to grow or propagate throughout the interposer until the structure ruptures, leading to reliability issues. To seek a resolution of the reliability enhancement, a better and clearer comprehension of the fracture physics and mechanisms is crucial. Thus, the study aims at investigating the fracture behaviors of glass interposers, provided by a local leading carrier supplier, under an accelerated thermal cycling (ATC) condition through numerical simulation and experimental testing. Focus is placed on the influences of the ATC loading on the mode I fracture toughness or stress intensity factor of the glass interposers, and more importantly, a design guideline is provided for improved fracture resistance or reliability. The study starts by evaluating the ultimate strength and critical fracture toughness of various glasses used in the interposer. In the thermal-mechanical numerical analysis, a 2D plane strain finite element analysis (FEA) technique is proposed. The proposed technique is benchmarked with the widely applied local fine mesh global simulation. Furthermore, to conduct fracture analysis, the virtual crack closure technique incorporating the degenerated element is employed. The calculated results are compared with each other and with the critical fracture toughness obtained from the experiments. At last, through parametric computational analysis, the geometry and material parameters most affecting the fracture behaviors are identified, and the optimal combinatorial design of these parameters is obtained. [Display omitted] • A methodology for fracture strength in glass interposers with dielectric coatings for dicing. • A deviation of fracture toughness between FEM and the theoretical solution was 4.3 %. • Factors involving crack length, interfacial crack effects, dielectric's elastic modulus. • Temperature effect is considered in the condition of crack length. • The interfacial crack length has the risk between glass and dielectric, when smaller than 40 μm. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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