Issue link: https://iconnect007.uberflip.com/i/1183414
NOVEMBER 2019 I DESIGN007 MAGAZINE 71 the process temperatures of the entire package assembly process (bumped die mounting and/ or wire-bond processing and encapsulation). Technical Challenges A number of 2.5D interposer-based prod- ucts have already materialized, but there are several technical challenges that need to be addressed: cost-effective through-silicon-via (TSV) and through-glass-via (TGV) formation, thin wafer and panel handling solutions, ther- mal management, and the lack of a broad 2.5D infrastructure network. Although 2.5D pack- age technology has reached a level of matu- rity, a number of issues remain that must be considered: selecting the specific material and methodology to be utilized, semiconductor procurement and die quality, and the area re- quired for single or multiple die mounting and interconnect. Key Planning Issues for 2.5D Packaging Assembly process methodologies will vary a great deal. Issues that will need to be resolved before beginning the development process in- clude: • Selecting suitable semiconductors for multiple die packaging • Establishing reliable sources for semiconductor elements • Specifying physical and environmental operating conditions • Defining package design constraints and process protocols • Stipulating electrical test method and post-assembly inspection criteria Conclusion Semiconductor packaging methodology will continue to evolve, and market analysts project a fairly steady growth in semiconductor package applications requiring the 2.5D interposer ele- ments. Although very difficult to predict, new semiconductor package innovations and solu- tions will likely continue to emerge. DESIGN007 Vern Solberg is an independent techni- cal consultant based in Saratoga, California, specializing in SMT and microelectronics design and manu- facturing technology. To read past columns or contact Solberg, click here. Table 1: 2.5D interposer design guidelines.