High Density RDL Technologies for Panel Level Packaging of Embedded DiesAuthors: Lars Boettcher, S. Kosmider, F. Schein, R. Kahle and A. Ostmann
Company: Fraunhofer Institute for Reliability and Microintegration (IZM), Technical University of Berlin
Date Published: 9/22/2019 Conference: SMTA International
This paper will show the development of 5µm L/S RDL routing density and chips with 50µm bump pitch. Here, the 6x6 mm² dies are symmetrically embedded into an organic laminate matrix. A PCB core (100µm thickness) with very low coefficient of thermal expansion (CTE) containing laser cut cavities is used, acting as a frame layer. Besides mechanical and handling stability, the usage of such a frame offers the advantage of pre-integrating additional features like local fiducials, through vias or power lines by conventional PCB processes. Within that frame, the dies are embedded by lamination of an organic build-up film with 25µm thickness equal to bump height. The chip contacts are then opened without the need of any micro via formation. Here a strong focus is set on RIE etching of the polymer material.
Highly accurate measurement of the real die position is essential for the following processing. The formation of the redistribution layer (RDL) is done in a semi-additive process (SAP) utilizing sputtering technique and direct imaging (LDI). To achieve the fine pitch demands, an adaptive imaging process is applied. Therefore, a newly developed LDI machine is used to write structures in a 7µm photoresist. This exposure also combines the measurement data of the real die position and the adaption of the exposure artwork, in order to achieve highest registration quality.
panel level packaging, adaptive imaging, direct imaging, 3D system in package, IC substrate
Members download articles for free:
Not a member yet?
What else do you get when you join SMTA? Read about all of the benefits that go along with membership.
Notice: Sharing of articles is restricted to just your immediate work group. Downloaded papers should not be stored on an external network or shared on the internet.