Thermomechanical stress analysis of laminated thick-film multilayer substrates

As an increasing number of polymer dielectric layers were laminated, the ma ximum bow values were measured layer by layer using a laser profilometry du ring thermal cycling. In the lamination process, a polymeric film is overla id on a silicon substrate using a polymeric adhesive. Since the lamination process uses relatively thick polymer films, the classical stress analyses assuming infinitesimally thin films, are no longer effective. In this lette r, a simple model based on the composite beam theory is presented to analyz e the experimental results, and compared with the well-known Stoney's formu la. The thermomechanical behavior of the laminated multilayer polymer films on a silicon substrate was better described by the proposed model, while a n error as much as 30% was involved using Stoney's formula. The model can b e applied for the design and fabrication of multilayer multichip module sub strates. (C) 1999 American Institute of Physics. [S0003-6951(99)03623-2].