Title :
Electron Attachment: A New Approach to H 2 Fluxless Solder Reflow for Wafer Bumping
Author :
Dong, C. Christine ; Patrick, Richard E. ; Karwacki, Eugene J.
Author_Institution :
Air Products & Chem. Inc., Allentown
Abstract :
Wafer bumping, via fluxless solder reflow, can be performed using electron attachment (EA) with nonflammable mixtures of hydrogen (= 4 vol%) in nitrogen. The EA process facilitates dissociation of molecular hydrogen at ambient pressure and a temperature significantly lower than that of thermal dissociation. Our studies suggest that the EA process promotes the formation of atomic hydrogen anions, which reduce solder oxides and facilitate fluxless solder reflows at temperatures close to the solder melting point.
Keywords :
dissociation; electron attachment; hydrogen; integrated circuit manufacture; manufacturing processes; nitrogen; reflow soldering; wafer bonding; atomic hydrogen anions; electron attachment; fluxless solder reflow; molecular hydrogen; nitrogen; nonflammable mixtures; solder melting point; solder oxides; thermal dissociation; wafer bumping; Adhesives; Assembly; Electron emission; Furnaces; Hydrogen; Nitrogen; Packaging; Printing; Temperature; Thermal degradation; Electric field effects; electron attachment; electron emission; fluxless solder reflow; hydrogen; wafer bumping; wafer-scale integration;
Journal_Title :
Advanced Packaging, IEEE Transactions on
DOI :
10.1109/TADVP.2007.901581
