Title :
Investigation of void-free electroplating method on copper column based solder bump for flip-chip interconnections
Author_Institution :
Corporate R&D Center, Toshiba Corp., Kanagawa, Japan
Abstract :
A void-free copper electroplating method on copper column based solder bump for flip-chip interconnection enabling reduction of the copper column void defects in the solder bump was investigated. The surface energy of the resist mask surface, which affects the wettability of the electroplating solution, was investigated by applying a surface modification technique with ultraviolet (UV) radiation treatment and oxygen plasma treatment. Also, the surface tension of electroplating solution was evaluated by employing an interfacial activator. Both the UV radiation treatment and the oxygen plasma treatment were found to increase the wettability on the electroplating resist surfaces and decrease the number of bubbles causing void defects in the solder bump. In addition, the interfacial activator decreased the number of bubbles and prevented the copper column void defects completely.
Keywords :
bubbles; electroplating; flip-chip devices; integrated circuit interconnections; plasma materials processing; solders; surface treatment; voids (solid); Cu; electroplating solution; flip-chip interconnections; interfacial activator; oxygen plasma treatment; resist surfaces; solder bump; surface energy; surface modification; surface tension; ultraviolet radiation treatment; void defects; void-free electroplating; wettability property; Capacitive sensors; Copper; Encapsulation; Large scale integration; Plasma applications; Resins; Resists; Surface tension; Surface treatment; Telephony;
Conference_Titel :
Electronics Materials and Packaging, 2005. EMAP 2005. International Symposium on
Print_ISBN :
1-4244-0107-0
DOI :
10.1109/EMAP.2005.1598245
