An Alternative Packaging Solution in Achieving Moisture Sensitivity Level One (1) for Small Outline Integrated Circuit (SOIC) Automotive Packages

In response to the need in the semiconductor industry to have a higher moisture sensitivity level (MSL) satisfying the no delamination criteria in all interfaces for automotive devices with a reasonable cost are the main objectives in this study. To attain these tasks, knowledge of the material components and a system in the evaluation process are the key to the success of this program. Different evaluation stages were initially defined and executed depending on bill-of-material (BOM) combination and complexities. Activities will also include process refinement, material selection, leadframe design improvement and surface enhancements. Initially, all existing critical process parameter conditions were identified and optimized to ensure a delamination-free package at time zero or after assembly after which moisture soaking is done at different conditions to identify and verify MSL capability. Once found incapable for no-delamination criteria, the change in mold compound material, leadframe design enhancement, and surface roughening will be introduced. For an SOIC package with the biggest silicon die and paddle size identified as the initial qualification test vehicle using a bare copper with spot silver type of leadframe, it was found out that with the optimized process parameter conditions and with the right mold compound can already achieve MSL 1 and even after 500 temperature cycles without any form of delamination in all regions - no need for further leadframe design enhancements, surface roughening treatments and additional process for surface activation. With this result on this specific package type, additional cost adders were avoided. Likewise, this solution will be extended to other package types with different surface finish for Pre-Plated Frames (PPFs) or Nickel-Palladium-Gold (NiPdAu) to check for process consistency and material compatibility.