Multirow gull-wing package for microelecronic devices

Abstract

A microelectronic device, in a multirow gull-wing chip scale package, has a die connected to intermediate pads by wire bonds. The intermediate pads are free of photolithographically-defined structures. An encapsulation material at least partially surrounds the die and the wire bonds, and contacts the intermediate pads. Inner gull-wing leads and outer gull-wing leads, located outside of the encapsulation material, are attached to the intermediate pads. The gull-wing leads have external attachment surfaces opposite from the intermediate pads. The external attachment surfaces of the outer gull-wing leads are located outside of the external attachment surfaces of the inner gull-wing leads. The microelectronic device is formed by mounting the die on a carrier, forming the intermediate pads without using a photolithographic process, and forming the wire bonds. The encapsulation material is formed, and the carrier is subsequently removed, exposing the intermediate pads. The gull-wing leads are formed on the intermediate pads.

What is claimed is: 
     
         1 . A microelectronic device, comprising:
 a first die;   intermediate pads,   wire bonds connecting the first die to the intermediate pads;   an encapsulation material surrounding the wire bonds, at least partially surrounding the first die and contacting the first die, and contacting the intermediate pads;   inner gull-wing leads contacting the intermediate pads, wherein:
 the inner gull-wing leads are located outside of the encapsulation material; 
 each of the inner gull-wing leads has a first portion which contacts the corresponding intermediate pad, a second portion continuous with the first portion and extending away from the intermediate pad, and a third portion continuous with the second portion, opposite from the first portion; and 
   outer gull-wing leads contacting the intermediate pads, wherein:
 the outer gull-wing leads are located outside of the encapsulation material; 
 each of the outer gull-wing leads has a first portion which contacts the corresponding intermediate pad, a second portion continuous with the first portion and extending away from the intermediate pad, and a third portion continuous with the second portion, opposite from the first portion; 
   
     
     
         2 . The microelectronic device of  claim 1 , wherein the intermediate pads are free of photolithographically-defined structures. 
     
     
         3 . The microelectronic device of  claim 1 , wherein the third portion of the inner gull-wing leads include an external attachment surface. 
     
     
         4 . The microelectronic device of  claim 1 , wherein the first portion of the inner gull-wing leads extends laterally in a first direction from a boundary with the second portion, wherein the first direction is parallel to a surface of the encapsulation material containing the intermediate pads. 
     
     
         5 . The microelectronic device of  claim 1 , wherein the third portion of the inner gull-wing leads extends laterally in a second direction, opposite from the first direction, from a boundary with the second portion, wherein the first direction is parallel to the surface of the encapsulation material containing the intermediate pads. 
     
     
         6 . The microelectronic device of  claim 1 , wherein the third portion of the inner gull-wing leads is not coplanar with the first portion, being offset by the second portion of the inner gull-wing leads; 
     
     
         7 . The microelectronic device of  claim 1 , wherein the third portion of the outer gull-wing leads includes an external attachment surface. 
     
     
         8 . The microelectronic device of  claim 1 , wherein the first portion of the outer gull-wing leads extends laterally in a first direction from a boundary with the second portion, wherein the first direction is parallel to a surface of the encapsulation material containing the intermediate pads. 
     
     
         9 . The microelectronic device of  claim 1 , wherein the third portion of the outer gull-wing leads extends laterally in a second direction, opposite from the first direction, from a boundary with the second portion of the outer gull-wing leads, wherein the first direction is parallel to the surface of the encapsulation material containing the intermediate pads. 
     
     
         10 . The microelectronic device of  claim 1 , wherein the third portion of the outer gull-wing leads is not coplanar with the first portion, being offset by the second portion. 
     
     
         11 . The microelectronic device of  claim 1 , wherein external attachment surfaces of the outer gull-wing leads are located outside of the external attachment surfaces of the inner gull-wing leads, wherein the external attachment surface of each outer gull-wing lead is located farther from a center of the first die than the external attachment surface of an inner gull-wing lead located adjacent to the outer gull-wing lead. 
     
     
         12 . The microelectronic device of  claim 1 , wherein each of the intermediate pads includes a plurality of wire stud bonds. 
     
     
         13 . The microelectronic device of  claim 1 , wherein each of the intermediate pads includes plated metal, wherein the plated metal conforms to contours of electrically conductive elements of the intermediate pads contacting the plated metal. 
     
     
         14 . The microelectronic device of  claim 1 , wherein each of the intermediate pads includes a preformed metal pad. 
     
     
         15 . The microelectronic device of  claim 1 , wherein each of the intermediate pads includes a supplementary metal pad, wherein the supplementary metal pad is continuous across the intermediate pad containing the supplementary metal pad. 
     
     
         16 . The microelectronic device of  claim 1 , wherein each of the intermediate pads includes a plurality of ribbon stitch bond strips. 
     
     
         17 . The microelectronic device of  claim 1 , further including an external component attached to at least one of the inner gull-wing leads or at least one of the outer gull-wing leads, wherein the external component is located outside of the encapsulation material. 
     
     
         18 . The microelectronic device of  claim 1 , wherein the inner gull-wing leads and the outer gull-wing leads are both located on two opposite sides of the microelectronic device. 
     
     
         19 . The microelectronic device of  claim 1 , wherein the inner gull-wing leads and the outer gull-wing leads are both located on four sides of the microelectronic device. 
     
     
         20 . The microelectronic device of  claim 1 , wherein the combined external attachment surfaces extend past the encapsulation material in all directions parallel to a surface of the encapsulation material containing the intermediate pads.