RDL’s (Redistributed Layers)

RDL’s (Redistribution Layers) is a key technology for 3D/2.5D IC integration and also for Fan-in & Fan-out (FOWLP) in advanced wafer-level packaging.

They can be fabricated in two ways.

  1. RDL fabrication with polymers as the passivation layer

  2. RDL fabrication with Cu damascene process

RDL fabrication with polymers as the passivation layer

RDL fabrication with polymers as the passivation layer

RDL fabrication with Cu damascene process

Single Damascene process

Single Damascene process
Single Damascene process
Double Damascene process

Double Damascene process

Process is similar to single damascene process.

Here Via and trenches are created first and then Cu deposition is done.