Li-Yin Gao

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Equiaxed copper (EG Cu), copper with columnar nanotwinned grains (C-NT Cu), and copper with mixed equiaxed and columnar grains (MG Cu) were electroplated on pads and redistributed layers (RDLs) with different dimensions. When the diameters of pads increased from 40 μm to 105 μm, the flatness of pads decreased from 34.5% to 24.0%. And the flatness gradually deteriorated from 16.5 % to 34.4 % with the increase of RDL width from 8 μm to 20 μm.

Equiaxed copper (EG Cu), copper with columnar nanotwinned grains (C-NT Cu), and copper with mixed equiaxed and columnar grains (MG Cu) were electroplated on pads and redistributed layers (RDLs) with different dimensions. When the diameters of pads increased from 40 μm to 105 μm, the flatness of pads decreased from 34.5% to 24.0%. And the flatness gradually deteriorated from 16.5 % to 34.4 % with the increase of RDL width from 8 μm to 20 μm.