Method of forming a packaged semiconductor device using ganged conductive connective assembly and structure

Abstract

A packaged semiconductor device has a die attach pad and leads disposed proximate to the die attach pad. Each lead has a lead bottom surface and a lead end surface. A semiconductor device attached adjacent to a top surface of the die attach pad, and a conductive clip is attached to the semiconductor device and at least one of the leads. The conductive clip comprises a first tie bar extending from a first side surface of the conductive clip. A package body encapsulates the semiconductor device, the conductive clip, portions of the leads, at least a portion of the first tie bar, and at least a portion of the die attach pad. Each lead end surface is exposed in a side surface of the package body, and an end surface of the first tie bar is exposed in a first side surface of the package body. A conductive layer is disposed on each lead end surface but is not disposed on the end surface of the first tie bar.

What is claimed is: 
     
         1 . A method of forming packaged semiconductor devices, comprising:
 providing a first conductive frame having joined conductive portions;   attaching semiconductor components to the first conductive frame;   providing a second conductive frame comprising interconnected conductive clips;   attaching the second conductive frame to the first conductive frame to provide a first sub-assembly, wherein the interconnected conductive clips are coupled to the first conductive frame;   encapsulating the first sub-assembly with an encapsulant to provide an encapsulated sub-assembly; and   separating the encapsulated sub-assembly to provide the packaged semiconductor devices, wherein the step of separating disconnects the interconnected conductive clips from the second conductive frame.   
     
     
         2 . The method of  claim 1 , further comprising:
 removing the joined conductive portions of the first conductive frame to form conductive flank surfaces disposed on side surfaces of the encapsulated sub-assembly; and   forming a conductive layer onto the conductive flank surfaces after the step of removing the joined conductive portions, wherein:
 the step of separating comprises providing each of the packaged semiconductor devices having portions of the conductive flank surfaces covered by the conductive layer. 
   
     
     
         3 . The method of  claim 2 , wherein:
 forming the conductive layer comprises:
 electroplating the conductive layer onto the conductive flank surfaces using the interconnected conductive clips to pass current through portions of the first conductive frame. 
   
     
     
         4 . The method of  claim 2 , wherein:
 providing the first conductive frame comprises providing:
 a first die pad; 
 a second die pad spaced apart from the first die pad; 
 a first lead disposed proximate to the first die pad; and 
 a second lead disposed proximate to the second die pad, wherein the first lead is adjoined to one of the second lead or the second die pad to provide one of the joined conductive portions; 
 a first one of the semiconductor components attached to the first die pad; and 
 a second one of the semiconductor components attached to the second die pad; 
   attaching the second conductive frame to the first conductive frame comprises:
 attaching a first one of the conductive clips to the first one of the semiconductor components and the first lead; and 
 attaching a second one of the conductive clips to the second one of the semiconductor components and the second lead; 
   encapsulating comprises leaving at least portions of the first conductive frame exposed from the encapsulated sub-assembly; and   removing comprises removing the one of the joined conductive portions to expose a flank surface of the first lead.   
     
     
         5 . The method of  claim 4 , wherein:
 providing the first conductive frame comprises providing the first lead physically connected to the second die pad within the first conductive frame such that the one joined conductive portion is interposed between the first lead and the second die pad.   
     
     
         6 . The method of  claim 4 , wherein:
 forming the conductive layer comprises:
 forming the conductive layer on bottom surfaces of the first die pad, the second die pad, the first lead, and the second lead. 
   
     
     
         7 . The method of  claim 2 , wherein:
 separating comprises providing the packaged semiconductor devices each having a distal end portion of the second conductive frame structure exposed to the outside of the encapsulating layer, and wherein the distal end portion is absent the conductive layer.   
     
     
         8 . The method of  claim 2 , wherein:
 removing the joined conductive portions comprises partially sawing into the encapsulated sub-assembly to completely remove the joined conductive portions.   
     
     
         9 . The method of  claim 2 , wherein:
 forming the conductive layer comprises forming a solderable material covering approximately 100% of the conductive flank surfaces.   
     
     
         10 . The method of  claim 1 , wherein:
 attaching the second conductive frame to the first conductive frame comprises attaching each of the interconnected conductive clips to a respective semiconductor component and to a respective part of the first conductive frame.   
     
     
         11 . A method of forming packaged semiconductor devices, comprising:
 providing a first conductive frame;   attaching semiconductor components to the first conductive frame;   providing a second conductive frame comprising a first clip interconnected to a second clip;   attaching the second conductive frame to the first conductive frame to provide a first sub-assembly;   encapsulating the first sub-assembly with an encapsulant to provide an encapsulated sub-assembly; and   separating the encapsulated sub-assembly to provide the packaged semiconductor devices, wherein the step of separating disconnects the first clip from the second clip.   
     
     
         12 . The method of  claim 11 , wherein:
 providing the first conductive frame comprises providing joined conductive portions; and   the method further comprises:
 removing the joined conductive portions of the first conductive frame to form conductive flank surfaces disposed on side surfaces of the encapsulated sub-assembly; and 
 forming a conductive layer over the conductive flank surfaces after the step of removing the joined conductive portions. 
   
     
     
         13 . The method of  claim 12 , wherein
 providing the joined conductive portions comprises providing a first lead connected to a first die pad.   
     
     
         14 . The method of  claim 11 , wherein:
 providing the second conductive frame comprises:
 providing the first clip physically interconnected to a first part of the second conductive frame with a first tie bar; and 
 providing the second clip physically interconnected to second part of the second conductive frame with a second tie bar. 
   
     
     
         15 . The method of  claim 11 , wherein attaching the second conductive frame comprises:
 attaching the first clip to the first conductive fame.   
     
     
         16 . The method of  claim 15 , wherein attaching the first clip comprises:
 attaching the first clip to a first semiconductor component.   
     
     
         17 . An encapsulated sub-assembly of semiconductor components, comprising:
 a first sub-assembly comprising:
 a first conductive frame having leads; 
 semiconductor components attached to the first conductive frame; and 
 a second conductive frame comprising conductive clips interconnected with tie bars, each conductive clip comprising a bonding portion connected to at least two leads; and 
   a package body structure comprising an encapsulating layer covering at least portions of the first sub-assembly.   
     
     
         18 . The encapsulated sub-assembly of  claim 17 , wherein:
 the leads comprise conductive flank surfaces exposed from side surfaces of the encapsulating layer; and   the encapsulated sub-assembly further comprises a conductive layer disposed at least adjacent to the conductive flank surfaces, wherein   
     
     
         19 . The encapsulated sub-assembly of  claim 17 , wherein:
 each conductive clip further comprises a die attach portion attached to one of the semiconductor components.   
     
     
         20 . The encapsulated sub-assembly of  claim 19 , wherein:
 the tie bars are attached to the die attach portion of each conducive clip and the second conductive fame.