The development of a folded 3D flexible package module based on flexible substrate

Increasingly aggressive requirements of active devices have challenged the physical limits of conventional packaging technologies. Bandwidth-intensive consumer and enterprise applications have precipitated an insatiable demand for ever-increasing density, functionality, and portability requirements of active devices. Such aggressive requirements, which have challenged the viability of conventional packaging technologies, have prompted researchers and engineers to contemplate suitable alternatives to placate such escalating demands. An innovative solution that is stimulating increasing interest is 3D flexible substrate packaging technology in part because of its high degree of scalability in a compact form-factor. However, this particular packaging topology has yet to mature into a mainstream solution in the industrial environment due to its prohibitive implementation costs. This paper proposes a practical, streamlined methodology of designing, fabricating and testing folded 3D flexible package modules that address both manufacturing costs and time-to-market sensitivities. Detailed in this paper is a pedagogical example of the proposed methodology that depicts the design optimization, fabrication, and characterization of daisy-chained chips incorporated into a 3D flexible package topology on flexible substrates. Electrical and pertinent reliability test results demonstrate the viability of the proposed methodology for folded 3D flexible package technology.