06358627 is referenced by 106 patents.

An integrated circuit assembly has pads of a chip electrically connected to pads of a substrate with rolling metal balls. A pliable material bonds the balls in movable contact with pads of the chip and substrate. Because the balls are relatively free to move, thermal expansion differences that would ordinarily cause enormous stresses in the attached joints of the prior art, simply cause rolling of the balls of the present invention, avoiding thermal stress altogether. Reliability of the connections is substantially improved as compared with C4 solder bumps, and chips can be safely directly mounted to such substrates as PC boards, despite substantial thermal mismatch.

Title
Rolling ball connector
Application Number
9/768112
Publication Number
6358627 (B2)
Application Date
January 23, 2001
Publication Date
March 19, 2002
Inventor
Jerzy M Zalesinski
Essex Junction
NY, US
William R Tonti
Essex Junction
NY, US
Mark V Pierson
Binghamton
NY, US
John U Knickerbocker
Hopewell Junction
NY, US
Wayne J Howell
Williston
VT, US
Wayne F Ellis
Jericho
VT, US
Thomas E Dinan
San Jose
CA, US
William T Chen
Endicott
NY, US
Claude L Bertin
South Burlington
VT, US
Joseph A Benenati
Hopewell Junction
NY, US
Agent
Robert A Walsh
US
Assignee
International Business Machines Corporation
NY, US
IPC
H01L 21/44
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