Method of making printed circuit board with varying depth conductive holes adapted for receiving pinned electrical components

Abstract

A method of making a printed circuit board in which openings of different length are formed using a cover atop one of the openings to prevent dielectric material from an interim layer of heat-deformable dielectric material from entering the opening when the sub-composite having the opening therein is bonded to a second sub-composite. The bonded sub-composites are then provided with a second opening which extends there-through, this second opening being longer than the first. Pins of an electrical component may then be inserted within the first and second openings of different length.

1 . A method of making a multilayered printed circuit board (PCB), said method comprising: 
 providing a first sub-composite including at least one dielectric layer and at least one opening therein having first and second opposing open end portions and extending substantially through said at least one dielectric layer;    positioning a cover on said first opposing open end portion of said at least one opening;    aligning said first sub-composite having said at least one opening therein having said cover on said first opposing open end portion with a second sub-composite including at least one dielectric layer such that said cover faces said second sub-composite;    positioning a layer of heat-deformable dielectric material between said first and second sub-composites; and    bonding said first and second sub-composites and said layer of heat-deformable dielectric material together using heat and/or pressure sufficient to deform said layer of heat-deformable material, said cover on said first open end portion of said at least one opening preventing said dielectric material of said layer of heat-deformable dielectric material from entering said at least one opening.    
     
     
         2 . The method of  claim 1  further including forming a second opening within said first and second sub-composites when said sub-composites are bonded, said second opening extending substantially through said first and second sub-composites and being longer than said at least one opening.  
     
     
         3 . The method of  claim 2  wherein said forming of said second opening within said first and second sub-composites is accomplished using a laser.  
     
     
         4 . The method of  claim 2  wherein said at least one opening is provided as a first conductive thru-hole prior to said positioning of said cover, said method further including providing a conductive material on the internal walls of said second opening to form at least a second conductive thru-hole within said bonded first and second sub-composites.  
     
     
         5 . The method of  claim 4  further including providing an electrical component having at least two pins extending there-from and inserting a first of said pins within said first conductive thru-hole and a second of said pins within said at least one second conductive thru-hole to form an electrical assembly.  
     
     
         6 . The method of  claim 5  further including positioning said electrical assembly within a housing to form an information handling system.  
     
     
         7 . The method of  claim 5  wherein said providing said conductive material on said internal walls of said second opening is accomplished using an electroplating operation.  
     
     
         8 . The method of  claim 1  further including providing each of said first and second sub-composites with at least one electrically conductive layer therein.  
     
     
         9 . The method of  claim 8  further including forming circuitry as at least part of said electrically conductive layers.  
     
     
         10 . The method of  claim 1  wherein said positioning of said cover on said first opposing open end portion of said at least one opening is accomplished using solder-mask material.  
     
     
         11 . The method of  claim 10  wherein said solder-mask material is provided in the form of a continuous layer and positioned on said first sub-composite, selected portions of said continuous layer of said solder-mask material thereafter being removed such that only the remaining portion thereof covers said at least one opening.  
     
     
         12 . The method of  claim 1  wherein said bonding of said first and second sub-composites and said layer dielectric material together using said heat and/or pressure sufficient to deform said layer of heat-deformable material is accomplished using a lamination process.  
     
     
         13 . The method of  claim 1  further including providing an opening with said layer of heat-deformable dielectric material and aligning said opening within said layer of heat-deformable material with said at least one opening within said first sub-composite and said cover positioned on said first opposing open end portion of said at least one opening during said bonding of said first and second sub-composites.