Methods of fabricating dual anode, flat panel electrophoretic displays

Claim 1

A method of completing fabrication of an electrophoretic display after a plurality of cathode conductor lines indicative of an X matrix have been formed on a planar glass sheet, comprising the steps of: coating the cathode conductor lines with a first insulating layer of photoresist, coating the first insulating layer with a first layer of silicon dioxide, coating a first layer of metal on said layer of silicon dioxide, coating said first layer of metal with a second layer of photoresist, coating said second layer of photoresist with a second layer of silicon dioxide, coating said second layer of silicon dioxide with a second layer of metal capable of being etched by a different etchant than said first, coating said second layer of metal with a third layer of metal capable of being etched by a different etchant from said first and second layer of metal, coating said third layer of metal with a fourth layer of metal capable of being etched by a different etchant than said first, second and third layers of metal, coating said fourth layer of metal with a third layer of photoresist, treating said fourth layer of photoresist to photolithographically form a matrix of lines transverse to said cathode conductor lines and thereafter selectively etching each layer of material until channels separate each of the lines of said matrix wherein there are first and second metal structures insulated from each other and from the cathode structure, coating the treated structure with a layer of silicon dioxide, removing said layer of silicon dioxide as coating said fourth metal layer with said fourth metal layer.

Claim 2

A method of completing fabrication of an electrophoretic display after a plurality of cathode conductor lines indicative of an X matrix have been formed on a planar glass sheet, comprising the steps of: coating the cathode conductor lines with a first insulating layer of photoresist, coating the first insulating layer with a first layer of silicon dioxide, coating a first layer of metal on said layer of silicon dioxide, coating said first layer of metal with a second layer of photoresist, coating said second layer of photoresist with a second layer of silicon dioxide, coating said second layer of silicon dioxide with a second layer of metal capable of being etched by a different etchant than said first, coating said second layer of metal with a third layer of metal capable of being etched by a different etchant from said first and second layer of metal, coating said third layer of metal with a fourth layer of metal capable of being etched by a different etchant than said first, second and third layers of metal, coating said fourth layer of metal with a third layer of photoresist, treating said fourth layer of photoresist to photolithographically form a matrix of lines transverse to said cathode conductor lines and thereafter selectively etching each layer of material until channels separate each of the lines of said matrix wherein there are first and second metal structures insulated from each other and from the cathode structure, coating the treated structure with a layer of silicon dioxide, removing said layer of silicon dioxide as coating said fourth metal layer with said fourth metal layer.

Claim 12

The method according to claim wherein the steps of coating with a photoresist insulating layer includes spinning said photoresist on said layer.

Claim 15

A method for fabricating an electrophoretic display of the type having an X-Y matrix for grid and cathode operation, comprising the steps of: depositing a first thin layer of a conductive metal on a carrier plate of glass, etching said layer to form a line pattern indicative of an X cathode matrix, depositing a first insulating layer of a photoresist resin on said X cathode matrix, depositing a first layer of silicon dioxide on said first layer of photoresist resin, depositing a second layer of a conductive metal on said layer of silicon dioxide, depositing a second insulating layer of a photoresist resin on said second metal layer, exposing said second layer of photoresist with a Y grid matrix mask, developing said photoresist according to said Y grid mask, etching said second layer of said conductive metal to form said Y grid matrix, removing the remainder of said second layer of photoresist, etching said layer of silicon dioxide with said etched second layer of conductive metal serving as a mask, depositing a third layer of photoresist resin on said etched second layer, depositing a second layer of silicon dioxide on said third layer of photoresist, depositing a first anode metal layer on said layer of silicon dioxide, depositing a second different anode metal layer on said first anode metal layer, depositing a fourth layer of a photoresist resin on said second different metal layer, treating said fourth layer of photoresist to photolithographically form an anode matrix of lines parallel to said Y grid matrix and perpendicular to said X cathode matrix, etching said first and second anode layers, covering said structure with a thin layer of silicon dioxide and etching away said second layer of anode metal leaving said first anode layer to provide an additional matrix designated as an anode matrix for said display.

Claim 16

A method for fabricating an electrophoretic display of the type having an X-Y matrix for grid and cathode operation, comprising the steps of: depositing a first thin layer of a conductive metal on a carrier plate of glass, etching said layer to form a line pattern indicative of an X cathode matrix, depositing a first insulating layer of a photoresist resin on said X cathode matrix, depositing a first layer of silicon dioxide on said first layer of photoresist resin, depositing a second layer of a conductive metal on said layer of silicon dioxide, depositing a second insulating layer of a photoresist resin on said second metal layer, exposing said second layer of photoresist with a Y grid matrix mask, developing said photoresist according to said Y grid mask, etching said second layer of said conductive metal to form said Y grid matrix, removing the remainder of said second layer of photoresist, etching said layer of silicon dioxide with said etched second layer of conductive metal serving as a mask, depositing a third layer of photoresist resin on said etched second layer, depositing a second layer of silicon dioxide on said third layer of photoresist, depositing a first anode metal layer on said layer of silicon dioxide, depositing a second different anode metal layer on said first anode metal layer, depositing a fourth layer of a photoresist resin on said second different metal layer, treating said fourth layer of photoresist to photolithographically form an anode matrix of lines parallel to said Y grid matrix and perpendicular to said X cathode matrix, etching said first and second anode layers, covering said structure with a thin layer of silicon dioxide and etching away said second layer of anode metal leaving said first anode layer to provide an additional matrix designated as an anode matrix for said display.