Method of making microelectronic packages including electrically and/or thermally conductive element

Abstract

A method of manufacturing a plurality of microelectronic packages including electrically and/or thermally conductive elements. The method includes providing a support structure having a plurality of protrusions and depressions extending outwardly from the support. A conductive element is then mated to the support structure in a male-to-female relationship. The depressions formed in the support structure and conductive element are used to house a microelectronic element such as a semiconductor chip. A substrate is provided so as to cover substantially each depression located in the conductive element. Leads interconnect contacts to the chip to terminals on the substrate. A curable encapsulant material may be deposited into the depression so as to protect and support the leads and the microelectronic element. Additionally, the curable encapsulant material forms part of the exterior of a single resulting chip package once the assembly is diced and cut into individual packages.

1 . A method of making a microelectronic assembly, comprising: 
 (a) providing a plurality of microelectronic packages;    (b) providing a support having a plurality of recesses, the support carrying a conductive element having a plurality of depressions, at least some of the depressions being disposed in a recess;    (c) assembling the conductive element with the microelectronic packages;    (d) removing the support after said assembling step; and    (e) severing the conductive element between the depressions to form individual conductive members for each microelectronic package.    
     
     
         2 . The method of  claim 1 , wherein the support comprises a mandrel having a plurality of recesses corresponding to the depressions in the conductive element.  
     
     
         3 . The method of  claim 2 , wherein the step of providing a support comprises depositing a conductive material on a surface of the support.  
     
     
         4 . The method of  claim 3 , wherein the surface of the support comprises a material that does not adhere to the conductive material.  
     
     
         5 . The method of  claim 4 , wherein the support comprises a material selected from the group consisting of molybdenum, steel, brass, and chromium.  
     
     
         6 . The method of  claim 5 , wherein the conductive material comprises a material selected from the group consisting of copper, nickel, and gold.  
     
     
         7 . The method of  claim 2 , wherein the step of providing the support comprises providing a metal mandrel with recesses.  
     
     
         8 . The method of  claim 2 , wherein the recesses have a depth of about the depth of the package.  
     
     
         9 . The method of  claim 1 , further comprising attaching bonding material to the conductive element.  
     
     
         10 . The method of  claim 9 , further comprising attaching the conductive element to connection pads of another microelectronic element using the bonding material.  
     
     
         11 . The method of  claim 1 , wherein each of said plurality of package comprises a semiconductor chip attached to a dielectric layer having terminal structures thereon and leads connecting to the chip and the terminal structures.  
     
     
         12 . The method of  claim 1 , further comprising introducing a flowable material into said depressions.  
     
     
         13 . The method of  claim 12 , wherein the conductive element defines bottom walls and side walls protruding forwardly from said bottom walls so that said walls cooperatively define said depressions, said side walls defining at least one pathway extending between adjacent ones of said depressions, said step of introducing a flowable material being performed so that said flowable material passes between at least some adjacent depressions through said pathways.  
     
     
         14 . The method of  claim 13 , wherein each said package includes a semiconductor chip having an operating frequency and each said pathway has dimensions less than the wavelength of electromagnetic radiation at said operating frequency.  
     
     
         15 . The method of  claim 13 , wherein said side walls are hollow and define wall spaces open to a rear wall of said conductive element, said at least one pathway communicating with said wall spaces, said step of removing said support being performed before said step of introducing said flowable material into said depressions, the method further comprising provided a rear covering layer overlying said rear walls of said depressions so that said rear covering layer blocks flow of said flowable material from said wall spaces onto exterior surfaces of said bottom walls.  
     
     
         16 . The method of  claim 12  wherein said step of introducing said flowable material is performed before said step of removing said support.