# Prediction of the Crack Front Shape of the Corner Interface Crack
In a significant study, [PERSON] (1991) conducted an extensive 3D analysis, focusing on a bimaterial plate featuring a central crack. A notable discovery was the characterization of the stress distribution around the crack tip by an asymptotic bimaterial K-field, which was confined to a small fraction of the plate's thickness, emphasizing the localized nature of the stress effects. Furthermore, authors have shown that the phase angles exhibit strong dependency on the bimaterial properties, with significant anti-plane mode deformations, particularly near the crack front and in close proximity to the free surface [12]. Expanding on this, [PERSON] and [PERSON] (1992) delved into a 3D finite element (FE) analysis of the crack growth and decohesion in a compliant thin film bonded to a rigid substrate. They indicated that in scenarios without decohesion, the stress intensity factor (SIF) along the leading edge of the crack reached a steady state when the crack length was approximately twice the film thickness. This phenomenon resulted in a nearly parabolic crack front along the leading edge [13]. In a complementary study, [PERSON] and [PERSON] (1993) conducted a detailed investigation to understand the intricate 3D field existing at a crack front within the bimaterial interface. They revealed a singular field at the crack tip and emphasized how material property mismatch along the interface induced a 3D strip along the bimaterial interface ahead of the crack tip [14]. Building on this, [PERSON] et al. (1998) contributed by deriving the novel domain integrals that allowed for the accurate extraction of mixed-mode SIFs along curved, three -dimensional bimaterial interface cracks. The results, including the SIFs and phase angles, exhibited excellent agreement with analytical solutions, validating the effectiveness and accuracy of the proposed approach [15]. [PERSON] and [PERSON] (1999) and (2001) have considered the three-dimensional interface cracking in electronic packages, which appears due to the thermal cycling and/or moisture diffusion, originating at edges and corners, where there is the high stress concentration. Authors concluded that the 3D fracture results cannot be anticipated based only on the 2D calculations [16; 17]. In a notable contribution to the field, [PERSON] (2006) derived the 3D asymptotic stress field in the proximity of a bimaterial penny-shaped interfacial discontinuity, employing the eigenfunction expansion method, and considering five distinct discontinuity-surface boundary conditions. He concluded that the interpretation of the macroscopic analysis should be viewed as a preliminary approximation when attempting to comprehend the intricate microscopic state of stress near the circumferential front of a bimaterial interfacial penny-shaped anti-crack [18]. Building on [PERSON]'s pioneering work, [PERSON], [PERSON], and [PERSON] (2006) introduced an innovative computational technique utilizing enriched crack tip elements, which were engineered to model the asymptotic behavior of interface crack tips. The analysis covered various bimaterial combinations under uniform remote tension and thermal loading [19]. In a related advancement, [PERSON], [PERSON], and [PERSON] (2007) presented an efficient numerical method for calculating the SIFs associated with the 3D interface cracks between dissimilar anisotropic materials, using the M\({}_{1}\) integral, obtained through the moving least-square method, and was implemented as a post-processing technique following Finite Element Method (FEM) simulations. The research displayed the method's superior accuracy when compared to the direct extrapolation (DE) method [20]. The work of [PERSON] and [PERSON] (2009) delves into a profound exploration of the influence of initial delamination shapes on the mechanics of 3D interfacial delamination within the IC packages, considering the three distinct front shapes, concave, straight, and convex.