Selective Laser Modification for Stress Mitigation and Warpage Reduction in Advanced 3DIC and Optoelectronic Packaging
Journal
IEEE Transactions on Components, Packaging and Manufacturing Technology
Journal Volume
16
Journal Issue
4
Start Page
917
End Page
921
ISSN
2156-3985
2156-3950
Date Issued
2026-02-16
Author(s)
Kao, Yu-Lin
Abstract
Selective laser scanning enables spatially localized tuning of polyimide (PI) thermomechanical properties to mitigate thermally induced stress and warpage in advancedd 3DIC and optoelectronic packaging, without changing the global material selection. Laserprocessed PI films are characterized and the resulting property changes are incorporated into a 2D planestrain finiteelement model. The representative coupon/model has an inplane span of 10 mm and a total thickness of 50 μm (47 μm Si with 3 μm PI). Local modification is applied only in 1 mm corner patches to target highstress regions, while the remaining PI remains pristine. Using a minimalconstraint (freewarpage) boundary condition and meshobjective evaluation metrics (warpage and nearcorner areaaveraged stress), the localized modification reduces warpage and mitigates stress concentration; solder fatigue trends are assessed via inelastic strainenergy density per cycle (Darveaux).
Subjects
advanced packaging
co-packaged optics (CPO)
finite element method (FEM)
laser modification
polyimide
thermomechanical stress
warpage
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Type
journal article