Advanced flip chip encapsulation: transfer molding process for simultaneous underfilling and postencapsulation

The process development for four flip chip molding compounds was based on material characterization by DSC, DMA and TMA. It was shown that the materials tested do allow reliable flip chip molding. Materials properties concerning processability and reliability are promising. There is strong potential of the technology for the increasing market of flip chip packages as certain types of BGA's and, with further miniaturization, CSP's. As these packages incorporate typically single dies, the transfer mold process can be adapted without major changes to existing equipment. Even for future developments such as one chip flip chip SIP's using advanced IC thinning and assembly methods, the flip chip molding underfill process is a successful vision for reliable encapsulation.