Method to create flexible connections for integrated circuits

Abstract

A method of producing flexible interconnections for integrated circuits, and, in particular, the forming of flexible or compliant interconnections preferably by a laser-assisted chemical vapor deposition process in semiconductor or glass substrate-based carriers which are employed for mounting and packaging multiple integrated circuit chips and selectively, other devices in the technology.

1 . A semiconductor package assembly comprising a substrate and at least one integrated circuit chip mounted on said substrate, an at least one flexible interconnect forming a compliant electrical connection between said substrate and said at least one integrated circuit chip. 
   
   
       2 . A method of fabricating a compliant probe substrate, comprising of a substrate and said at least one flexible interconnect forming a compliant probe lead (interconnect). 
   
   
       3 . A compliant probe substrate as claimed in  claim 2 , wherein a substrate is made of semiconductor, ceramic, organometallic materials in a passive form or having active or passive components assembled onto it. 
   
   
       4 . A compliant probe substrate as claimed in  claim 3 , wherein the compliant interconnect or the tip of it comprises of mechanically and electrically durable and/or physically abrasive materials. 
   
   
       5 . A semiconductor package assembly as claimed in  claim 1 , wherein said compliant flexible interconnect is constituted of a material deposited by laser-assisted chemical vapor deposition (LCVD). 
   
   
       6 . A semiconductor package assembly as claimed in  claim 1 , wherein said compliant flexible interconnect comprises a generally upright C-shaped member extending between facing surfaces of said substrate and said at least one integrated circuit chip. 
   
   
       7 . A semiconductor package assembly as claimed in  claim 6 , wherein a tip of said C-shaped member, which supports said at least one integrated circuit chip is provided with a solder wettable metallurgical material. 
   
   
       8 . A semiconductor package assembly as claimed in  claim 7 , wherein said solder wettable metallurgical material comprises an Ni adhesion layer and solder wettable gold (Au). 
   
   
       9 . A semiconductor package assembly as claimed in  claim 6 , wherein a plurality of said C-shaped members are spaced in x-y planar dimensions at varied spacings from a neutral point so as to compensate for differences in coefficients of expansion between said substrate and said at least one integrated circuit chip encountered responsive to heat generated during operation of said semiconductor package assembly. 
   
   
       10 . A semiconductor package assembly as claimed in  claim 8 , wherein said adhesion layer and said solder wettable metallurgical material are deposited by laser-assisted chemical vapor deposition. 
   
   
       11 . A semiconductor package assembly as claimed in  claim 8 , wherein said adhesion layer and said solder wettable metallurgical material are deposited through selective surface plating. 
   
   
       12 . A semiconductor package assembly as claimed in  claim 8 , wherein said adhesion layer and said solder wettable metallurgical material are surrounded by an insulator for maintaining the solder within the flexible interconnect tip. 
   
   
       13 . A method of forming flexible electrical interconnects for a semiconductor package assembly, comprising providing a substrate and at least one integrated circuit chip mounted on said substrate, and interposing at least one said flexible interconnect between said substrate and said at least one chip to form a compliant electrical connection between said substrate and said at least one integrated circuit chip. 
   
   
       14 . A method as claimed in  claim 13 , wherein said compliant flexible interconnect is constituted of a material deposited by laser-assisted chemical vapor deposition (LCVD). 
   
   
       15 . A method as claimed in  claim 14 , wherein said complaint flexible interconnect comprises a spirally shaped member produced by an optical system in operative conjunction with said LCVD process. 
   
   
       16 . A method as claimed in  claim 15 , wherein said spirally-shaped complaint flexible interconnect is formed on a motor-driven goniometer arrangement in conjunction with a focused laser beam projected through said optical system and LCVD. 
   
   
       17 . A method as claimed in  claim 13 , wherein said compliant flexible interconnect comprises a generally upright C-shaped member extending between facing surfaces of said substrate and said at least one integrated circuit chip. 
   
   
       18 . A method as claimed in  claim 17 , wherein a tip of said C-shaped member, which supports said at least one integrated circuit chip is provided with a solder wettable metallurgical material. 
   
   
       19 . A method as claimed in  claim 18 , wherein said solder wettable metallurgical material comprises an Ni adhesion layer and solder wettable gold (Au). 
   
   
       20 . A method as claimed in  claim 17 , wherein a plurality of said C-shaped members are spaced in x-y planar dimensions at varied spacings from a neutral point so as to compensate for differences in coefficients of expansion between said substrate and said at least one integrated circuit chip encountered responsive to heat generated during operation of said semiconductor package assembly. 
   
   
       21 . A method as claimed in  claim 19 , wherein said adhesion layer and said solder wettable metallurgical material are deposited by laser-assisted chemical vapor deposition. 
   
   
       22 . A method as claimed in  claim 19 , wherein said adhesion layer and said solder wettable metallurgical material are deposited through selective surface plating. 
   
   
       23 . A method as claimed in  claim 19 , wherein said adhesion layer and said solder wettable metallurgical material are surrounded by an insulator for maintaining the solder within the flexible interconnect tip.