Constitutive modeling of moulding compounds [electronic packaging applications]

Basic thermo-mechanical property estimation of a 3D-crosslinked epoxy/SiO2 interface using molecular modelling

“…small batch (novosf5), which has been excluded from the averaging procedure; it is suspected that insufficient 3D-connectivity leads to this obvious deviation. The averaged value of 4.26 GPa for the Young's modulus is in reasonable agreement with first experimental estimates from dynamic mechanical analysis (DMA) at 1 Hz of 2.03 GPa [16] or values found in the literature [12]. The elastic moduli are calculated from geometry-optimized (i.e.…”

“…However, the complex composition of most industrially used encapsulation compounds is a safely guarded secret. For this investigation, the model epoxy system Epoxy Phenol Novolac (EPN) was chosen, which is similar to industrially used chip-encapsulation moulding compounds [12,13]. The epoxy resin and the Bisphenol-A hardener are depicted in Fig.…”

Reliability modelling for packages in flexible end-products

“…For the Copper leadframe a stiffness of 123GPa, a Poison ratio of 0.35, and a CTE of 16.3 ppm/ºC is used. For the epoxy used, such as die-attach and moulding compound, dedicated DMA tests are performed to obtain the linear viscoelastic properties [11]. For inlay materials, such as paper, polyurethane, dedicated tensile tests are performed to obtain isotropic material properties.…”

Influence of matrix viscoelastic properties on thermal conductivity of TCA – Numerical approach

“…where G and K denote the shear and bulk relaxation modulus, which are time t and temperature T dependent, e eff V is the effective volumetric strain contribution [3,4].…”

“…In order to apply numerical simulation it is required to have an appropriate description of the thermal and mechanical behavior of polymers. Most often polymers are described by cure dependent or independent linear viscoelastic model [3,5]. Having this model, which parameters in fact can be measured experimentally, it is possible to simulate the stress and strain field caused by polymer curing and shrinkage phenomena and finally assess the thermal conductance accordingly.…”