ナノスプリング層が熱変形を吸収する高信頼パワー半導体実装構造

摘要

A highly reliable joint structure for a power-semiconductor device was developed. In this structure, a die has a nano-spring layer on its surface and this layer is bonded to a metallic circuit by soldering. The nano-spring layer is a structure composed of multiple nanoscale springs made by the glancing angle deposition method. Thermal stress in the structure is reduced because the nano-spring layer absorbs the difference of the thermal deformations between the die and the metallic circuit. In this study, a manufacturing method for a nano-spring layer made of copper and aluminum was developed and the mechanical characteristics and thermal characteristics of the nano-spring were measured. In addition, a manufacturing process for a power semiconductor device by using a die with the nano-spring layer was demonstrated. This demonstration confirmed that the manufacturing process can be carried out in the same manner as that using a conventional die and successfully manufactures a joint structure composed of a nano-spring layer.