Evaluation of low cure temperature dielectric materials for EMWLP and TSV

This paper presents the evaluation results of low temperature cure dielectrics in terms of process ability, adhesion to Si, SiN, Cu RDL and mold compound substrates. Minimum via opening of 10µm without residue was achieved for 5µm dielectric film thickness. Adhesion tests results were conducted based on JEDEC standards for MSL1 and unbiased HAST testing and they demonstrated that the low temperature cure dielectric materials have good adhesion on Si, SiN, Cu RDL and mold compound surfaces. Dielectric materials also showed good adhesion in multi layer coatings (2 layer). Fabricated test vehicles, each using one of the dielectric material, were subjected to ball shear tests at the solder UBM. Ball shear results showed good adhesion of the dielectric materials onto the UBM metal pads.