Circuit-and-heat-dissipation assembly and method of making the same

Abstract

Disclosed herein is a circuit-and-heat-dissipation assembly which includes: a heat sink including a heat absorbing base and a heat dissipating element, the heat absorbing base having a circuit-forming surface and an element-forming surface, the heat dissipating element protruding from the element-forming surface for dissipating heat conducted from the heat absorbing base into an ambient environment; an insulator layer formed on the circuit-forming surface; and a patterned circuit formed on the insulator layer and having an electroless plating layer which has a patterned catalyst seed layer comprising an active metal and formed on the insulator layer, and a reduced metal layer formed on the catalyst seed layer. Also disclosed herein is a method of making the circuit-and-heat-dissipation assembly.

What is claimed is: 
     
         1 . A method of making a circuit-and-heat-dissipation assembly, comprising:
 preparing a heat sink that includes a heat absorbing base and a heat dissipating element, the heat absorbing base having a circuit-forming surface and an element-forming surface, the heat dissipating element protruding from the element-forming surface for dissipating heat conducted from the heat absorbing base into an ambient environment;   forming an insulator layer on the circuit-forming surface; and   forming a patterned circuit on the insulator layer,   wherein the patterned circuit is formed on the insulator layer by forming a patterned electroless plating layer on the insulator layer using electroless plating techniques, and   wherein the patterned electroless plating layer is formed on the insulator layer by: forming a catalyst seed layer comprising an active metal on the insulator layer; and forming a reduced metal layer on the catalyst seed layer by reducing metal ions through the catalyst seed layer.   
     
     
         2 . The method as claimed in  claim 1 , wherein the catalyst seed layer is a patterned catalyst seed layer. 
     
     
         3 . The method as claimed in  claim 1 , wherein the catalyst seed layer is a non-patterned catalyst seed layer and is subjected to patterning. 
     
     
         4 . The method as claimed in  claim 1 , wherein a patterned electroplating layer is formed on the electroless plating layer using electroplating techniques. 
     
     
         5 . The method as claimed in  claim 2 , wherein the patterned catalyst seed layer is formed on the insulator layer by:
 covering the insulator layer with a patterned mask, the patterned mask being formed with a pattern of through-holes that corresponds to a pattern of the patterned catalyst seed layer; and   applying an ink containing the active metal onto the patterned mask to fill the through-holes with the ink.   
     
     
         6 . The method as claimed in  claim 5 , wherein the pattern of the patterned mask is formed by laser ablation techniques. 
     
     
         7 . The method as claimed in  claim 5 , wherein the circuit-forming surface of the heat absorbing base is curved in shape, the patterned mask being flexible and conforming to the circuit-forming surface when covering the insulator layer. 
     
     
         8 . The method as claimed in  claim 1 , further comprising:
 forming at least one hole in the insulator layer, such that the hole exposes a contact region of the circuit-forming surface and that the hole is aligned with a gap defined by two soldering ends of a pair of conductive lines of the patterned circuit; and   forming a heat dissipating block on the contact region, such that the heat dissipating block extends from the contact region through the hole in the insulator layer and into the gap.   
     
     
         9 . The method as claimed in  claim 1 , wherein the heat dissipating element is in the form of fins. 
     
     
         10 . The method as claimed in  claim 1 , wherein the reduced metal layer is formed on the catalyst seed layer by reducing the metal ions in an electroless plating bath through the catalyst seed layer.