Advanced Techniques for Short Defect Repair to Improve Yield in Packaging Architectures

Heterogeneous integration with new 2.5 and 3D packaging architectures brings greater overall system performance but can result in large and sophisticated multi-die units where every defect can dramatically affect yield, translating to high scrap cost. This paper examines short defect shaping technology, specifically focusing on the challenges encountered when repairing small line/space (L/S) defects. The method is expected to result in significant scrap cost savings and consequently improve yield. The technology employs advanced algorithms for fine L/S ablation with minimal substrate penetration, targeting repairs down to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2/2 \mu \mathrm{m}$</tex>. System stability, spot size, and laser jitter are critical for precision. Integrated optical 3D measurements and real-time feedback ensure accurate ablation without substrate damage. The results demonstrate successful ablation of fine line spaces down to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2/2 \mu \mathrm{m}$</tex>, confirming the technology's effectiveness in maintaining reliability and performance in advanced packaging units.