Single mask screening process and structure produced thereby

Abstract

A process of forming a multi-layer feature on a ceramic or organic article in which first and second layers of paste are sequentially screened through a screening mask wherein the screening mask has not been moved between screening steps. A structure produced by this process is also disclosed.

What is claimed is:  
     
         1 . A method of forming a multi-layer feature on an electronic substrate article, the method comprising the steps of: 
 a. placing a screening mask having at least one aperture over the electronic substrate article;    b. screening a first paste through the at least one aperture of the screening mask to form a first layer of the multi-layer feature;    c. screening a second paste through the same at least one aperture of the same screening mask used in the first screening step and onto the first paste to form a second layer of the multi-layer feature in alignment with the first layer of the multi-layer feature, wherein the screening mask has not been moved between the two screening steps; and    d. removing the screening mask.    
     
     
         2 . The method of    claim 1    further comprising the step of heating the multi-layer feature.  
     
     
         3 . The method of    claim 1    wherein in the first screening step, the paste only partially fills the at least one aperture of the screening mask.  
     
     
         4 . The method of    claim 3    wherein in the second screening step, the paste fills the remainder of the at least one aperture of the screening mask.  
     
     
         5 . The method of    claim 1    wherein the first paste is wet when the second paste is screened onto it.  
     
     
         6 . The method of    claim 1    wherein the first and second pastes are metal-containing pastes.  
     
     
         7 . The method of    claim 1    wherein the first and second pastes are insulative pastes.  
     
     
         8 . The method of    claim 1    wherein one of the first and second pastes is a metal-containing paste and the other of the first and second pastes is an insulative paste.  
     
     
         9 . The method of    claim 1    wherein the electronic substrate article is an organic article.  
     
     
         10 . The method of    claim 2    wherein the electronic substrate article is an organic article, the first and second pastes comprise solder and the step of heating the multi-layer feature causes reflow of the solder layers.  
     
     
         11 . The method of    claim 2    wherein the electronic substrate article is a ceramic substrate and the step of heating causes sintering of the multi-layer feature.  
     
     
         12 . The method of    claim 11    wherein the ceramic substrate is a ceramic greensheet and the method further comprises, prior to the step of heating: screening a paste onto at least a second ceramic greensheet to form a wiring feature; 
 removing the screening mask; and  
 stacking and laminating the ceramic greensheets.  
 
     
     
         13 . The method of    claim 11    wherein the ceramic substrate is a ceramic greensheet laminate.  
     
     
         14 . The method of    claim 11    wherein the ceramic substrate is a sintered ceramic substrate.  
     
     
         15 . The method of    claim 1    wherein the screening mask is a metal mask.  
     
     
         16 . The method of claim I wherein the screening mask is that used in silk screen printing.  
     
     
         17 . The method of    claim 1    wherein the first and second steps of screening are by extrusion screening.  
     
     
         18 . The method of    claim 1    wherein the first and second steps of screening are by silk screen printing.  
     
     
         19 . The method of    claim 1    wherein the multi-layer feature is a termination pad.  
     
     
         20 . The method of    claim 1    wherein the multi-layer feature is a wiring line.  
     
     
         21 . The method of    claim 1    wherein the multi-layer feature is part of a capacitor.  
     
     
         22 . A multi-layer feature structure on an electronic substrate article comprising: 
 an electronic substrate article; and    a multi-layer feature structure comprising:    a first portion adjacent to the electronic substrate article; and    a second portion having a bottom and a periphery wherein the first portion contacts the bottom, and surrounds the periphery of, the second portion so that the second portion is captured by the first portion.    
     
     
         23 . The multi-layer feature structure of    claim 22    wherein the multi-layer feature is a termination pad.  
     
     
         24 . The multi-layer feature structure of    claim 22    wherein the multi-layer feature is a wiring line.  
     
     
         25 . The multi-layer feature structure of    claim 22    wherein the multi-layer feature is part of a capacitor.  
     
     
         26 . The multi-layer feature structure of    claim 22    wherein the electronic substrate article is an organic substrate.  
     
     
         27 . The multi-layer feature structure of    claim 22    wherein the electronic substrate article is a ceramic greensheet.  
     
     
         28 . The multi-layer feature structure of    claim 22    wherein the electronic substrate article is a ceramic greensheet laminate.  
     
     
         29 . The multi-layer feature structure of    claim 22    wherein the electronic substrate article is a sintered ceramic substrate.