Redistribution Layer Recess for Probe Pad Optical Identification

The space between bond pad and probe pad is segmented by forming a recess, dividing the continuous surface into distinct regions. This segmentation creates a visual boundary that helps test devices differentiate between adjacent pads, improving identification precision without adding complex optical layers.

Instead of applying an optical identification layer across the entire surface, the recess is formed only in the specific local region between bond pad and probe pad. This localized modification provides identification functionality exactly where needed, maintaining simplicity elsewhere while improving test precision.

The identification function is extracted from the optical identification layer concept and implemented through a simple recess structure. By removing the need for additional optical materials and layers, the solution achieves pad identification through geometric modification alone, reducing device complexity while maintaining test precision.

Instead of adding a new optical identification layer, the invention uses the recess to create an optical contrast that copies the identification function. The recess acts as a shadow or visual marker that test devices can detect, providing the same identification capability without the complexity of additional layers.