Rework of polymeric dielectric electrical interconnect by laser photoablation

Claim 1

A method of disconnecting metallization in an electrical interconnect, comprising the steps of: providing an electrically conductive metallization on portions of a planar substrate; disposing a first layer of ablative photoabsorptive polymeric dielectric on and in contact with the entire top surfaces of said metallization and the substrate regions not covered by said metallization, thereby forming on the entire substrate a first composite wiring layer comprising said metallization and said first polymeric dielectric layer wherein the top surface of said first polymeric dielectric layer is exposed; directing a beam of laser energy having suitable wavelength and sufficient power density at said exposed top surface of said first polymeric dielectric layer so as to ablate said first polymeric dielectric layer in the irradiated areas, thereby exposing a portion of said underlying metallization through an ablated opening in said first polymeric dielectric layer; etching said exposed metallization using said first polymeric dielectric layer alone as an etch mask, thereby electrically disconnecting said metallization in the exposed areas while leaving the remaining first polymeric dielectric layer and disconnected metallization intact; and coating a second polymeric dielectric layer on and in contact with said remaining first polymeric dielectric layer and said disconnected metallization so as to form on the entire substrate a second composite wiring layer comprising said disconnected metallization and said remaining first and said second polymeric dielectric layers.

Claim 2

A method of disconnecting metallization in an electrical interconnect, comprising the steps of: providing an electrically conductive metallization on portions of a planar substrate; disposing a first layer of ablative photoabsorptive polymeric dielectric on and in contact with the entire top surfaces of said metallization and the substrate regions not covered by said metallization, thereby forming on the entire substrate a first composite wiring layer comprising said metallization and said first polymeric dielectric layer wherein the top surface of said first polymeric dielectric layer is exposed; directing a beam of laser energy having suitable wavelength and sufficient power density at said exposed top surface of said first polymeric dielectric layer so as to ablate said first polymeric dielectric layer in the irradiated areas, thereby exposing a portion of said underlying metallization through an ablated opening in said first polymeric dielectric layer; etching said exposed metallization using said first polymeric dielectric layer alone as an etch mask, thereby electrically disconnecting said metallization in the exposed areas while leaving the remaining first polymeric dielectric layer and disconnected metallization intact; and coating a second polymeric dielectric layer on and in contact with said remaining first polymeric dielectric layer and said disconnected metallization so as to form on the entire substrate a second composite wiring layer comprising said disconnected metallization and said remaining first and said second polymeric dielectric layers.

Claim 22

A method as recited in claims 1, 15, 16, 17, 18, 19 or 20 wherein said method consists essentially of said steps.

Claim 24

A method of disconnecting copper in a polymeric dielectric layer of an electrical interconnect and then surrounding the disconnected copper with a composite polymeric dielectric layer so as to rework the electrical interconnect, comprising the steps of: providing copper on portions of a planar polymeric dielectric substrate; disposing a first thin layer of ablative photoabsorptive polymeric dielectric on and in contact with the entire top surfaces of said copper and said polymeric dielectric substrate regions not covered by said copper, thereby forming on the entire polymeric dielectric substrate a first composite wiring layer consisting essentially of said copper and said first polymeric dielectric layer wherein the top surface of said first polymeric dielectric layer is exposed; directing an excimer laser beam having suitable wavelength and sufficient power density at said exposed top surface of said first polymeric dielectric layer so as to ablate said first polymeric dielectric layer in the irradiated areas, thereby exposing a portion of said underlying copper through an ablated opening in said first polymeric dielectric layer; etching said exposed copper using said first polymeric dielectric layer alone as an etch mask, thereby electrically disconnecting said copper in the exposed areas while leaving the remaining first polymeric dielectric layer and disconnected copper intact; and coating a second polymeric dielectric layer on and in contact with said remaining first polymeric dielectric layer and said disconnected copper so as to form on the entire polymeric dielectric substrate a second composite wiring layer consisting essentially of said disconnected copper and said remaining first and said second polymeric dielectric layers.

Claim 25

A method of disconnecting copper in a polymeric dielectric layer of an electrical interconnect and then surrounding the disconnected copper with a composite polymeric dielectric layer so as to rework the electrical interconnect, comprising the steps of: providing copper on portions of a planar polymeric dielectric substrate; disposing a first thin layer of ablative photoabsorptive polymeric dielectric on and in contact with the entire top surfaces of said copper and said polymeric dielectric substrate regions not covered by said copper, thereby forming on the entire polymeric dielectric substrate a first composite wiring layer consisting essentially of said copper and said first polymeric dielectric layer wherein the top surface of said first polymeric dielectric layer is exposed; directing an excimer laser beam having suitable wavelength and sufficient power density at said exposed top surface of said first polymeric dielectric layer so as to ablate said first polymeric dielectric layer in the irradiated areas, thereby exposing a portion of said underlying copper through an ablated opening in said first polymeric dielectric layer; etching said exposed copper using said first polymeric dielectric layer alone as an etch mask, thereby electrically disconnecting said copper in the exposed areas while leaving the remaining first polymeric dielectric layer and disconnected copper intact; and coating a second polymeric dielectric layer on and in contact with said remaining first polymeric dielectric layer and said disconnected copper so as to form on the entire polymeric dielectric substrate a second composite wiring layer consisting essentially of said disconnected copper and said remaining first and said second polymeric dielectric layers.