600mm x 600mm Fan-Out Panel Level Package (FOPLP) as an Alternative to Lead-Frame-Free Quad Flat No Lead (QFN) Package

The leadframe in a traditional Quad Flat No-Lead (QFN) is the most integral part of the package. In a QFN, the leadframe and die are typically electrically connected using copper or gold bond wires. The mold compound widely used to achieve electrical insulation, assists in corrosion resistance, reliability, and durability in the package.The global semiconductor lead frame market which was projected to have CAGR of 6.9% from 2022 to 2029 was severely impacted during COVID-19 and only exhibited growth of 1.7% in 2020 as compared to 2019. Consequently, post-pandemic sales have risen sharply by 15.8% due to rising consumer demands in electronic device usage and network subscriptions. Shortages and supply chain disruptions have adversely affected the leadframe market in addition to rising prices of raw materials which have prompted manufacturers to look for alternatives.This paper presents an alternative to the traditional QFN package, which is a redistribution layer (RDL) based Land Grid Array (LGA) process, utilizing a Fan-Out Panel Level Packaging (FOPLP) process on a 600mm x 600mm panel. The FOPLP is a Chip First Fan-out (FO) process that enables multiple FO platforms without the use of leadframes or wire bonds for die to lead connection. This process simplifies factory operations with a common Bill of Materials (BOM) across all QFNs, provides wettable flanks for automotive requirements, and eliminates the need for tie bars which are an inherent flaw in traditional leadframe processing. The specific FOPLP process utilized for these QFNs is a molded direct contact structure which does not require polyimide and thus eliminates vias and capture pads on all Fan-Out build up layers.FOPLP electrical connections are achieved with Cu redistribution layers (RDL) and Cu studs. For our evaluation, a 600mm x 600mm FO panel was utilized. The test vehicle attributes are 40 Leads, 5mm x 5mm, 850um nominal thickness and 400um pad pitch. In this example, 16 strips measuring 70mm x 250mm are created on the 600mm x 600mm panel to be drop-in compatible with existing backend QFN testing equipment. Other strip sizes and die sizes are also possible with the leadframe-free QFN Fan-Out package as the electrical connections from chip to lead are built with laser direct imaging.We will review process flow differences between traditional QFN and the leadframe-free QFN strip built using 600mm x 600mm FOPLP technology, supply chain differences, warpage and fan-out ratio, wettable flanks for automotive requirements, assembly yield and open/short (OS) test results. Lastly, we will present the Component Level Reliability (CLR) of the leadframe-free RDL based Land Grid Array (LGA) package.