Mechanical -laser structure on printed circuit board and carrier

Abstract

A mechanical-laser structure on a printed circuit board and a carrier. A method for fabricating the mechanical-laser structure includes the following steps. A substrate is provided. A first through hole is formed in the substrate by mechanical drilling An epoxy plug is formed within the first through hole. A conductive layer is formed on the substrate by compression. The conductive layer is patterned to form conducting wires and exposes the epoxy plug. A micro via is formed within the epoxy plug by laser drilling.

What is claimed is:  
     
         1 . A method for fabricating a mechanical-laser structure on a printed circuit board and a carrier, the method comprising: 
 providing a substrate;    forming a first through hole in the substrate by mechanical drilling;    forming a plug within the first through hole;    forming a first conductive layer on the substrate and the plug;    patterning the first conductive layer to form conducting wires, wherein the plug is exposed; and    forming a second through hole in the plug by a laser for laser drilling, wherein a diameter of the second through hole is narrower than the first through hole.    
     
     
         2 . The method of    claim 1   , wherein the method further comprises forming a second conductive layer on a sidewall of the first through hole before forming the plug within the first through hole.  
     
     
         3 . The method of    claim 2   , wherein the step of forming the second conductive layer includes electroplating.  
     
     
         4 . The method of    claim 1   , wherein a conductive material fills the second through hole after forming the second through hole.  
     
     
         5 . The method of    claim 1   , wherein a third conductive layer is formed on a sidewall of the second through hole after forming the second through hole.  
     
     
         6 . The method of    claim 5   , wherein the step of forming the third conductive layer includes electroplating.  
     
     
         7 . The method of    claim 1   , wherein the laser used for forming the second through hole includes carbon dioxide laser.  
     
     
         8 . The method of    claim 1   , wherein the laser used for forming the second through hole includes Yttrium-Aluminum-Garnet laser.  
     
     
         9 . A mechanical-laser structure, the structure comprising: 
 a substrate having at least a first through hole; and    a plug within the first through hole, wherein a second through hole is formed in the plug, and a diameter of the second through hole is narrower than the first through hole.    
     
     
         10 . The structure of    claim 9   , wherein the plug includes epoxy.  
     
     
         11 . The structure of    claim 9   , wherein a first conductive layer is formed on the substrate and exposes a portion of the second through hole.  
     
     
         12 . The structure of    claim 11   , wherein a second conductive layer, which is coupled with the first conductive layer, is located on a sidewall of the second through hole.  
     
     
         13 . The structure of    claim 11   , wherein the conductive layer comprises a patterned circuit layer.  
     
     
         14 . A substrate having a mechanical-laser structure, the structure comprising: 
 a central layer having at least a first through hole;    a first conducting wire on the central layer, wherein the first through hole is uncovered;    a first conductive layer on a sidewall of the first through hole, wherein the first conducting wire is coupled with the first conductive layer;    an insulation layer enclosing over the substrate including the first conducting wire, wherein the insulation layer also fills the first through hole to form a plug, and a second through hole whose diameter is narrower than the first through hole is formed within the plug;    a second conducting wire on the insulation layer, wherein a portion of the second through hole remains exposed; and    a second conductive layer on a sidewall of the second through hole, wherein the second conducting wire is coupled with the second conductive layer.    
     
     
         15 . The structure of    claim 14   , wherein the insulation layer includes epoxy.  
     
     
         16 . The structure of    claim 14   , wherein the central layer is formed by alternately stacking a plurality of patterned third conductive layers and a plurality of insulation layers.  
     
     
         17 . The structure of    claim 16   , wherein some of the third conductive layers are coupled with the first conductive layer.  
     
     
         18 . The structure of    claim 14   , wherein a blind hole is formed in the insulation layer, and a fourth conductive layer which is coupled with the first conducting wire and the second wire is formed in the blind hole.