Method for forming three-dimensional circuitization and circuits formed

Abstract

A method for forming three-dimensional circuitization in a substrate is provided for forming conductive traces and via contacts. In the method, a substrate formed of a substantially insulating material is first provided, grooves and apertures in a top surface of and through the substrate are then formed, followed by filling the grooves and apertures with an electrically conductive material such as a solder. The method can be carried out at a low cost to produce high quality circuit substrates by utilizing an injection molded solder technique or a molten solder screening technique to fill the grooves and the apertures. The grooves and the apertures in the substrate may be formed by a variety of techniques such as chemical etching, physical machining and hot stamping.

1 . A method for forming conductive elements in a substrate comprising the steps of: 
 providing a substrate of a substantially electrically insulating material,    forming grooves and apertures in a top surface of and through said substrate, and    filling said grooves and apertures with an electrically conductive material.    
     
     
         2 . A method for forming conductive elements in a substrate according to  claim 1  further comprising the step of forming said grooves and apertures by a technique selected from the group consisting of chemical etching, physical machining and hot stamping.  
     
     
         3 . A method for forming conductive elements in a substrate according to  claim 1 , wherein said grooves and apertures formed are grooves for line traces and apertures for plugs.  
     
     
         4 . A method for forming, conductive elements in a substrate according to  claim 1 , wherein said substrate is formed of a polymeric material.  
     
     
         5 . A method for forming conductive elements in a substrate according to  claim 1  wherein said electrically conductive material is a solder.  
     
     
         6 . A method for forming conductive elements in a substrate according to  claim 1 , wherein said electrically conductive material is a lead based solder.  
     
     
         7 . A method for forming conductive elements in a substrate according to  claim 1  further comprising the step of cooling said electrically conductive material until it solidifies.  
     
     
         8 . A method for forming conductive elements in a substrate according to  claim 1  further comprising the step of forming a passivation layer over said substrate and said grooves and apertures filled with electrically conductive material.  
     
     
         9 . A method for forming conductive elements in a substrate according to  claim 8 , wherein said passivation layer is formed of a dielectric material.  
     
     
         10 . A method for forming conductive elements in a substrate according to  claim 1  further comprising the step of forming line traces and via contacts in said insulating substrate by a molten solder screening technique.  
     
     
         11 . A method for forming conductive elements in a substrate according to  claim 1  further comprising the step of forming via contacts that provide electrical communication between conductive regions in said insulating substrate.  
     
     
         12 . A method for forming conductive elements in a substrate according to  claim 1  further comprising the step of forming via contacts that provide electrical communication between conductive regions in said insulating substrate.  
     
     
         13 . A method for forming a three-dimensional circuit in a substrate comprising the steps of: 
 providing an insulating substrate,    forming at least two surface indentations in said insulating substrate, and    filling said at last two surface indentations with an electrically conductive metal.    
     
     
         14 . A method for forming a three-dimensional circuit in a substrate according to  claim 13 , wherein said insulating substrate is fabricated of a polymeric material.  
     
     
         15 . A method for forming a three-dimensional circuit in a substrate according to  claim 13 , wherein said at least two surface indentations formed comprises a groove and an aperture.  
     
     
         16 . A method for forming a three-dimensional circuit in a substrate according to  claim 13  further comprising the step of forming a line trace and a via contact in said insulating substrate.  
     
     
         17 . A method for forming a three-dimensional circuit in a substrate according to  claim 13  further comprising the step of forming, a via contact for providing electrical communication between two line traces.  
     
     
         18 . A method for forming a three-dimensional circuit in a substrate according to  claim 13  further comprising the step of providing electrical communication between two conductive regions by said at least two surface indentations filled with said electrically conductive metal.  
     
     
         19 . A method for forming a three-dimensional circuit in a substrate according to  claim 13  further comprising the step of electrically connecting two conductive regions by a conductive trace formed in one of said at least two surface indentations.  
     
     
         20 . A method for forming a three-dimensional circuit in a substrate according to  claim 13  further comprising the step of electrically connecting two conductive regions by a via contact formed in said at least two surface indentations.  
     
     
         21 . A method for forming a three-dimensional circuit in a substrate according to  claim 13  further comprising the step of filling said at least two surface indentations by a molten solder screening technique.  
     
     
         22 . A method for forming a three-dimensional circuit in a substrate according to  claim 13  further comprising the step of filling said at least two surface indentations with a solder material.  
     
     
         23 . An electronic substrate comprising: 
 a substrate formed of a substantially insulating material,    at least one surface groove in said substrate filled with a conductive metal, and    at least one aperture in said substrate filled with said conductive metal providing electrical communication to said at least one surface grove.    
     
     
         24 . An electronic substrate according to  claim 23  further comprising a passivation layer overlaying said substrate, said surface groove and said aperture.  
     
     
         25 . An electronic substrate according to  claim 24 , wherein said passivation layer is formed of a dielectric material.  
     
     
         26 . An electronic substrate according to  claim 23  further comprising at least one line trace formed in said at least one surface groove and at least one via contact formed in said at least one aperture.  
     
     
         27 . A method for forming a chip-scale package for direct chip attach comprising the steps of: 
 providing an IC chip having a plurality of conductive pads formed in an active surface,    attaching a pliable film having a plurality of apertures formed therein positioned corresponding to locations of said plurality of conductive pads to said active surface of said IC chip,    filling said plurality of apertures with an electrically conductive material forming a plurality of electrically conductive columns for making electrically contacts with said plurality of conductive pads, and    forming a plurality of solder balls on said pliable film each in electrical communication with one of said plurality of electrically conductive columns.    
     
     
         28 . A method for forming a chip-scale package for direct chip attach according to  claim 27 , wherein said IC chip is unitary with a semiconductor wafer.  
     
     
         29 . A method for forming a chip-scale package for direct chip attach according to  claim 27 , wherein said pliable film is a polymeric-based film.  
     
     
         30 . A method for forming a chip-scale package for direct chip attach according to  claim 27 , wherein said pliable film is made of a material selected from the group consisting of polyimide, polyamide, polyester and PTFE.  
     
     
         31 . A method for forming a chip-scale package for direct chip attach according to  claim 27  further comprising the step of filling said plurality of apertures with a high melting point solder material.  
     
     
         32 . A method for forming a chip-scale package for direct chip attach according to  claim 27  further comprising the step of filling said plurality of apertures with a solder such as 97/3 Pb/Sn.  
     
     
         33 . A method for forming a chip-scale package for direct chip attach according to  claim 27  further comprising the step of forming said plurality of solder balls on said pliable film by a technique selected from solder injection molding, solder ball preform placement and solder paste screening.  
     
     
         34 . A method for forming a chip-scale package for direct chip attach according to  claim 27  further comprising the step of forming said plurality of solder balls in an eutectic Pb/Sn solder.  
     
     
         35 . A method for forming a wafer-level package for flip chip attachment comprising the steps of: 
 providing an IC chip in a wafer having a plurality of conductive pads formed in an active surface,    attaching a pliable film having a plurality of apertures formed therein positioned corresponding to locations of said plurality of conductive pads on said active surface of said IC chip,    filling said plurality of apertures with an electrically conductive material forming a plurality of electrically conductive columns for making electrical contacts with said plurality of conductive pads,    forming a plurality of conductive runners on top of said pliable film each in electrical communication with one of said plurality of electrically conductive columns, and    forming a plurality of solder balls each on one of said plurality of conductive runners in electrical communication with one of said plurality of conductive pads on said IC chip through one of said plurality of electrically conductive columns.    
     
     
         36 . A method for forming a wafer-level package for flip chip attachment according to  claim 35 , wherein said pliable film is a polymeric-based film selected from the group consisting of a polyimide film, a polyamide film, a polyester film and a PTFE film.  
     
     
         37 . A method for forming a wafer-level package for flip chip attachment according to  claim 35  further comprising the step of filling said plurality of apertures with a high melting point solder material.  
     
     
         38 . A method for forming a wafer-level package for flip chip attachment according to  claim 35 , wherein said step of filling said plurality of apertures with an electrically conductive material being carried out by a screen printing or a solder injection molding technique.  
     
     
         39 . A method for forming a wafer-level package for flip chip attachment according to  claim 35  further comprising the step of forming said plurality of solder balls on said pliable film by a technique selected from the group consisting of solder injection molding, solder ball preform placement and solder paste screening.  
     
     
         40 . A method for forming a wafer-level package for flip chip attachment according to  claim 35  further comprising the step of forming said plurality of solder balls in a solder such as eutectic Pb/Sn.  
     
     
         41 . A method for forming a wafer-level package for flip chip attachment according to  claim 35  further comprising the steps of: 
 severing said IC chip from said wafer, and  
 encapsulating said IC chip in a molding compound exposing said plurality of solder balls.  
 
     
     
         42 . A method for forming an IC chip/leadframe package comprising the steps of: 
 providing an IC chip having a plurality of conductive pads in an active surface,    providing a leadframe equipped with a plurality of lead fingers for making electrical connections with said IC chip,    attaching an electrically insulating film to said active surface of the IC chip and said plurality of lead fingers, said electrically insulating film having a plurality of apertures therethrough exposing said plurality of conductive pads and said plurality of lead fingers,    filling said plurality of apertures with an electrically conductive material making electrical connection with said plurality of conductive pads and forming a plurality of conductive runners on top of said electrically insulating film such that each runner electrically connecting a conductive pad to a lead finger, and    encapsulating said IC chip and said plurality of lead fingers in a molding compound.    
     
     
         43 . A method for forming an IC chip/leadframe package according to  claim 42 , wherein said electrically insulating film is a polymeric-based film selected from the group consisting of a polyimide film, a polyamide film, a polyester film and a PTFE film.  
     
     
         44 . A method for forming an IC chip/leadframe package according to  claim 42  further comprising the step of providing said leadframe in a metal comprises copper.  
     
     
         45 . A method for forming an IC chip/leadframe package according to  claim 42  further comprising the step of filling said plurality of apertures with a high melting point solder material.  
     
     
         46 . A method for forming an IC chip/leadframe package according to  claim 42  further comprising the step of filling said plurality of apertures with an electrically conductive material by a solder injection molding or a screen printing technique.  
     
     
         47 . A method for forming a chip-on-flex package comprising the steps of: 
 providing an IC chip having a plurality of conductive pads in an active surface,    providing a flexible film equipped with a plurality of apertures and a plurality of thin film wiring on a top surface, and    filling said plurality of apertures with an electrically conductive material when a bottom surface of said flexible film is positioned juxtaposed to said active surface of said IC chip such that a plurality of conductive runners are formed on said top surface of the flexible film and a plurality of conductive columns are formed in said plurality of apertures for providing electrical communication between said plurality of conductive pads on the IC chip and said plurality of thin film wiring on the flexible film.    
     
     
         48 . A method for forming a chip-on-flex package according to  claim 47  further comprising the step of providing said flexible film in a flexible circuitry.  
     
     
         49 . A method for forming a chip-on-flex package according to  claim 47  further comprising the step of providing a pre-amp chip for use in a disk drive application.  
     
     
         50 . A method for forming a chip-on-flex package according to  claim 47  further comprising the step of filling said plurality of apertures with a solder material that comprises lead.  
     
     
         51 . A method for forming a chip-on-flex package according to  claim 47  further comprising the step of filling said plurality of apertures by a solder injection molding or a screen printing technique.  
     
     
         52 . A method for forming a chip-on-flex package according to  claim 47  further comprising the step of providing said flexible film made of a material selected from the group consisting of polyimide, polyamide, polyester and PTFE.