Design structure for final via designs for chip stress reduction
View Patent ↗A design structure to provide a package for a semiconductor chip that minimizes the stresses and strains that arise from differential thermal expansion in chip to substrate or chip to card interconnections. An improved set of design structure vias above the final copper metallization level that mitigate shocks during semiconductor assembly and testing. Other embodiments include design structures having varying micro-mechanical support structures that further minimize stress and strain in the semiconductor package.
1. A semiconductor package comprising:
at least one ball limiting metallurgy layer;
at least one final passivation layer having at least one final passivation layer via wherein the at least one final passivation layer via has a diameter,
wherein the final passivation layer is below the ball limiting metallurgy layer;
at least one aluminum layer in a via in a hard dielectric passivation layer;
said aluminum layer having at least one projection wherein a portion of the final passivation layer is above the at least one projection and a portion of the final passivation layer is below the at least one projection;
said via in a hard dielectric passivation layer having a smaller diameter than the final passivation layer via diameter;
at least one last metallization copper layer below the aluminum layer;
at least one via below the last metallization copper layer with a reduced stress and stain in the semiconductor package.