Measurement of dielectric anisotropy of BPDA-PDA polyimide in multilayer thin-film packages

The measured dielectric anisotropy of BPDA-PDA polyimide, obtained from a specially designed test vehicle, is presented. The multilayer thin-film structure is representative of its actual use in multichip carrier (MCM-D) applications both from the cross sectional dimensions and fabrication sequence point of view. Modeling is performed using finite-element and electromagnetic techniques and the effect of anisotropy on signal propagation and crosstalk are verified through time-domain measurements.<
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