Testing-for-manufacturing (TFM) for ultra-thin IPD on InFO

Abstract

The Integrated Fan Out (InFO) technology can accom-plish package miniaturization and successfully achieve “More than Moore's Law.” Its substrate-free technology also brings great cost-effective attraction to mobile and wearable applications. Ultra-thin integrated passive devices (IPDs) with high capacitance density can further shrink the InFO size and boost the bandwidth. Although the cost for the IPD in the InFO package is negligible, failed IPDs can shut down the whole InFO package. This would cause an entire mobile system loss about 104 times of cost penalty. Thus the quality of each IPD chip must be ensured before surface-mounted on the InFO, and applying the final testing (FT) of the IPD is necessary. In this paper, we propose a novel optical positioning FT system combined with testing-for-manufacturing (TFM) methodology for the ultra-thin IPD chips testing. For validation of the novel comprehensive FT solution in the volume production domain, ultra-thin and ultra-small-area IPD chips with several millions sample sizes have passed through the FT system.