06189208 is referenced by 66 patents and cites 56 patents.

The invention provides a flip chip mounting process in which a layer of electrically insulating adhesive paste is applied on a substrate having bond pads, covering the bond pads with the adhesive. Electrically conductive polymer bumps are formed on bond pads of a flip chip to be bonded to the substrate, and the polymer bumps are at least partially hardened. The bond pads of the flip chip are then aligned with the bond pads of the substrate, and the at least partially hardened polymer bumps are pushed through the adhesive on the substrate to contact directly and bond the polymer bumps to the bond pads of the substrate. This process results in direct electrical and mechanical bonding of the polymer bumps between the chip and substrate bond pads, even though the adhesive film was applied on the substrate in a manner that covered the substrate bond pads. The polymer bumps displace the adhesive as they are pushed through it and expand laterally on the substrate bond pads. As a result, the area around the polymer bumps between the chip and the substrate is filled with the adhesive, in the manner of an underfill, whereby a separate, post-bond underfill process is not required.

Title
Flip chip mounting technique
Application Number
9/378847
Publication Number
6189208 (B1)
Application Date
August 23, 1999
Publication Date
February 20, 2001
Inventor
Minoru Wada
Ina-machi
US
Toshihiro Mori
Moriyama
US
Masanori Akita
Otsu
US
Koji Ito
Otsu
US
Richard H Estes
Hollis
NH, US
Agent
Theresa A Lober
US
Assignee
Toray Engineering Co
US
Polymer Flip Chip
MA, US
IPC
H05K 3/34
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