Fan-Out Panel Level Package with Fine Pitch Pattern

Abstract

As the industry moves Beyond Moore, there has been much efforts for the next-generation of packaging, among which Fan-out wafer-level-package is getting significant attention with its high-degree heterogeneous integration capability, small form factor. As fan-out package steps on mass production stage, Panel level package (PLP) is emerging as the most cost-effective technology featuring a large and efficient working area for a varied unit size and array, while commercialization of PLP needs to address some of significant technical challenges in particular by facing RDL formation with fine pitch pattern for specific applications. Here, we report on the fine line/space with an emphasis upon the development of new technology possibly needed at ever demanding set application (i.e. 2.5D organic interposer) requiring the most fine ones. The proposed process has demonstrated its fine pattern capability with good line shape below 2/2 line and space. Panel warpage behaviors were compared between organic and glass carriers when mulit RDLs had been formed. In case of RDL first processes, the panel warpage with rigid carriers such as thick glass were less than that with organic ones throughout an entire RDL process including dielectric coating, photolithography, copper metal plating and other wet processes, while the surface flatness on which pattern would be formed were showing no distinct difference.