Author :
Kawahara, Toshimi
Author_Institution :
Fujitsu Labs. Ltd., Kawasaki, Japan
fDate :
5/1/2000 12:00:00 AM
Abstract :
SuperCSP is fabricated by building up the interposer with high reliability encapsulant on the chip by wafer level packaging technology. New encapsulation technology enables real chip-sized package from a package perspective. It is also a known good encapsulated die (KGED) from a die perspective. The reasons why board level reliability of SuperCSP is good regardless of extremely low bump-standoff height are as follows. (1) The C.T.E of encapsulant for SuperCSP is close to that of motherboard, so that the encapsulant layer effectively reduces stress occurring in the solder interconnecting portion. (2) Encapsulant with high adhesive strength reinforces and fixes the delicate connecting portion of chip and post, and also does not allow its deformation. (3) Connecting portion of solder ball and post has a strong structure and can tolerate the stress because solder balls catch hold of the whole surface of metal posts, which stick out from the encapsulant and have a mound like structure
Keywords :
chip scale packaging; encapsulation; integrated circuit reliability; soldering; SuperCSP; adhesive strength; bump-standoff height; high reliability encapsulant; known good encapsulated die; mound like structure; solder balls; solder interconnecting portion; wafer level packaging technology; Adhesive strength; Electrodes; Encapsulation; Joining processes; Resists; Semiconductor device packaging; Stress; Trademarks; Transfer molding; Wafer scale integration;
Journal_Title :
Advanced Packaging, IEEE Transactions on
DOI :
10.1109/6040.846637