DocumentCode :
1287158
Title :
Development of 25- \\mu{\\rm m} -Pitch Microbumps for 3-D Chip Stacking
Author :
Yu, Aibin ; Kumar, Aditya ; Ho, Soon Wee ; Yin, Hnin Wai ; Lau, John H. ; Su, Nandar ; Houe, Khong Chee ; Ching, Jong Ming ; Kripesh, Vaidyanathan ; Chen, Scott ; Chan, Chien-Feng ; Chao, Chun-Chieh ; Chiu, Chi-Hsin ; Chan, Chang-Yueh ; Chang, Chin-Huang
Author_Institution :
Inst. of Microelectron., Agency for Sci., Singapore, Singapore
Volume :
2
Issue :
11
fYear :
2012
Firstpage :
1777
Lastpage :
1785
Abstract :
The development of ultrafine-pitch microbumps and the thermal compression bonding (TCB) process for advanced 3-D stacking technology are discussed in this paper. Microbumps, consisting of Cu pillars and thin Sn caps with a pitch of 25 μm, are fabricated on an Si chip by the electroplating method. Total thickness of the Cu pillar and the Sn cap is 10 μm. Electroless nickel and immersion gold pads with a total thickness of 4 μm are fabricated on an Si carrier. TCB of the Si chip and the Si carrier is conducted on an FC150 flip-chip bonder, and a good joining with higher than 10-MPa die shear strength is achieved. After bonding, the bond line thickness between the Si chip and the Si carrier is filled with the selected capillary underfill material. Void-free underfilling is achieved with underfill materials which have a fine filler size. Ninety percent of the bonded samples can pass the thermal cycling test (-40/+125°C) with 1000 cycles and the highly accelerated temperature/humidity stress test (130°C , 85% RH) for 96 h.
Keywords :
bonding processes; electroplating; elemental semiconductors; fine-pitch technology; flip-chip devices; gold; nickel; silicon; stacking; 3D chip stacking; Cu; Cu pillars; FC150 flip-chip bonder; Ni; Si; Si chip; accelerated temperature/humidity stress test; capillary underfill material; electroless nickel; electroplating method; immersion gold pads; size 4 mum; temperature 130 degC; thermal compression bonding; thermal cycling test; thin Sn caps; time 96 h; ultrafine-pitch microbumps; void-free underfilling; Bonding; Nickel; Passivation; Silicon; Stacking; Stress; Tin; Cu pillar; electroless nickel/immersion gold (ENIG); interconnects; microbump; stacking;
fLanguage :
English
Journal_Title :
Components, Packaging and Manufacturing Technology, IEEE Transactions on
Publisher :
ieee
ISSN :
2156-3950
Type :
jour
DOI :
10.1109/TCPMT.2012.2203130
Filename :
6305526
Link To Document :
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