Pulse Reverse Electroplating for Copper Filling in High Aspect Ratio Through Glass Vias for Advanced Packaging

Heterogenous integration enables increased functional density by integration of multiple chips or components into a single package. This integration leads to an increase of the overall package size and is a challenge for the dimensional stability of the package. One potential solution to this challenge is the application of new materials like glass to provide unparalleled flatness and dimensional stability. Inclusion-free filling of high aspect ratio (HAR) through glass vias (TGVs) is crucial for significantly enhancing the performance and reliability of advanced electronic packaging. This study explores the application of pulse reverse electroplating (PRE) to achieve defect-free copper electroplating in HAR TGVs. Defect-free filling of HAR TGVs is vital for the performance and reliability of advanced electronic devices. Addressing this issue directly impacts the efficiency and longevity of the packaging products. The PRE technique, which utilizes alternating current pulses combined with advanced DC electroplating processes, effectively mitigates the formation of inclusions and voids, ensuring excellent bridging and superconformal filling even in challenging structures. The study examines more complex PRE techniques to achieve conformal filling for small features in interposer-like structures. Our study shows that these methods can provide inclusion-free filling for certain through hole dimensions, as verified by x-ray investigations. The data demonstrates PRE’s potential to enhance structural integrity and improve thermal and electrical conductivity. Future research will focus on refining these processes to accommodate diverse structure dimensions, further enhancing their reliability and versatility. By refining the techniques and exploring new combinations of electroplating methods, including testing new in-house synthesized molecules with tailored electrochemical performance, we aim to further enhance the versatility and reliability of HAR TGV filling processes to meet the evolving demands of advanced electronic packaging.