Method for making a circuit plate

Abstract

A method for making a circuit plate includes: forming first holes in an insulating layer; forming a conductive layer on the insulating layer such that a portion of the conductive layer fills the first holes; grinding the conductive layer such that the portion of the conductive layer remains in the first holes to form a pattern of conductive traces; forming a dielectric protective layer that covers the insulating layer and the conductive traces; forming a pattern of second holes in the protective layer such that a portion of each of the conductive traces is accessible through a respective one of the second holes; and forming conductive bumps that are respectively connected to the conductive traces.

1 . A circuit plate comprising; a substrate having a dielectric portion that has a planar circuit-forming surface; an insulating layer formed on the circuit-forming surface and formed with a pattern of first holes; a pattern of conductive traces formed on said circuit-forming surface within said first holes, respectively; a protective layer formed on said insulating layer and formed with a plurality of second holes such that each of said conductive traces is accessible through a respective one of said second holes; and a pattern of conductive bumps, each of which extends into a respective one of said second holes to connect electrically with a respective one of said conductive traces and each of which protrudes outwardly from the respective one of said second holes.  
   
   
       2 . The circuit plate of  claim 1 , wherein said conductive traces are made from a conductive paste.  
   
   
       3 . The circuit plate of  claim 2 , further comprising a pattern of metal traces, each of which is formed on and covers a respective one of said conductive traces, each of said conductive bumps being formed on a respective one of said metal traces.  
   
   
       4 . The circuit plate of  claim 1 , wherein each of said conductive traces includes at least one metal film that is made from a first metal selected from the group consisting of Ni, Au, Cu, and Al.  
   
   
       5 . The circuit plate of  claim 4 , further comprising a pattern of metal traces, each of which is formed on and covers a respective one of said conductive traces, each of said conductive bumps being formed on a respective one of said metal traces.  
   
   
       6 . The circuit plate of  claim 5 , wherein each of said metal traces includes at least one metal film that is made from a second metal selected from the group consisting of Ni, Au, Cu, and Al.