Bonding Characteristics of Underfilled Ball Grid Array Packaging

Abstract

In recent years, ball grid array (BGA) package has been widely used in the portable electronic device, which can offer miniaturization and increased functional density. Thus, the failure chances of package under shock and vibration environments have been increased. In this work, we investigate the effect of underfill properties on bonding characteristics of underfilled BGA packaging. Three kinds of underfill materials with different additive content were formulated. Dynamic mechanical analysis (DMA), tensile test and shear test were conducted to examine the material properties of underfill resin such as the storage modulus (EA), glass transition temperature (T g ), mechanical and adhesion strength. In addition, the three-point bending test was conducted for underfilled BGA assemblies to investigate the mechanical reliability of BGA interconnects. The results indicate that the underfill resin should have a proper T g to ensure the mechanical properties, and modulus of toughness of underfill resin acts as an important factor rather than mechanical strength and EA (Stiffness) to ensure the mechanical reliability of BGA assembly.

Evaluation of thermal fatigue crack propagation in underfill resin materials for electronic packages

“…The growth of such fatigue cracks may degrade the connection reliability. [2][3][4] Therefore, it is important to fully understand the fatigue crack growth characteristics of underfill resin materials under thermal cycle loading.…”

“…However, when thermal stress is applied repeatedly, fatigue cracks may be initiated in underfill resin materials. The growth of such fatigue cracks may degrade the connection reliability 2–4 . Therefore, it is important to fully understand the fatigue crack growth characteristics of underfill resin materials under thermal cycle loading.…”