Title :
A new flip-chip technology for high-density packaging
Author :
Smith, Donald L. ; Alimonda, Andrew S.
Author_Institution :
Xerox Palo Alto Res. Center, CA, USA
Abstract :
We have used sputter-deposition and standard lithography to fabricate arrays of cantilevered metal micro-springs on 80 μm pitch, and we have obtained 100% electrical contact to 200-pad chips bonded face-down against them. Four-point resistance is 0.38 Ω for Mo-Cr springs on Al pads. Since the contacts themselves are not bonded and since the springs have high elastic compliance, this technology is very resistant to mechanical shock and stress, can accommodate large nonplanarity in mating surfaces, facilitates replacement of bad chips, and could be used for wafer-scale probing
Keywords :
contact resistance; flip-chip devices; integrated circuit packaging; lithography; sputter deposition; 0.38 ohm; 80 micron; Al; Mo-Cr; array fabrication; cantilevered metal micro-spring; elastic compliance; electrical contact; flip-chip technology; four-point resistance; high-density packaging; lithography; mechanical shock; nonplanarity; sputter deposition; stress; wafer-scale probing; Contacts; Dielectric substrates; Electric shock; Fingers; Lithography; Packaging; Springs; Sputtering; Tensile stress; Wafer bonding;
Conference_Titel :
Electronic Components and Technology Conference, 1996. Proceedings., 46th
Conference_Location :
Orlando, FL
Print_ISBN :
0-7803-3286-5
DOI :
10.1109/ECTC.1996.550814
