Method and apparatus for balling and assembling ball grid array and chip scale array packages

Abstract

A method and apparatus are provided for attaching conductive materials to a substrate and for attaching a semiconductor chip to a substrate. A pallet is provided with pockets to hold the conductive materials, the substrate is placed over the pallet, and the semiconductor chip is placed over the substrate. The assembled semiconductor package is then placed in a heating oven or reflowed and the conductive materials and semiconductor chip are simultaneously attached to the substrate. Also provided is a stencil for varying the pockets into which the conductive materials are placed. In uses involving the stencil, a pallet with a full array of pockets is used and a stencil with holes corresponding to the desired pattern of application of the conductive materials is placed over the pallet. When the conductive materials are applied over the stencil, they fill only those pockets in the pallet that correspond to the desired pattern of application.

What is claimed is:  
     
         1 . An apparatus for attaching conductive materials to conductive pads on a substrate, comprising: 
 a plate having pockets arranged in a pattern so that one group of the pockets align respectively with the conductive pads of one substrate, and so that at least one other group of the pockets align respectively with the conductive pads of at least one other substrate having conductive pad locations different than conductive pad locations on the one substrate.    
     
     
         2 . The apparatus of  claim 1 , further comprising means for placing the conductive materials in an appropriate group of the pockets.  
     
     
         3 . The apparatus of  claim 1 , further comprising a heating device for heating the conductive materials to attach the conductive materials permanently to the conductive pads.  
     
     
         4 . The apparatus of  claim 1 , wherein the heating device is a heating oven.  
     
     
         5 . An apparatus for attaching conductive materials to conductive pads on a semiconductor substrate, comprising: 
 a pallet having pockets arranged in a pattern so that one group of the pockets align respectively with the conductive pads on one semiconductor substrate, and so that at least one other group of the pockets align respectively with the conductive pads of at least one other semiconductor substrate having conductive pad locations different than conductive pad locations on the one semiconductor substrate.    
     
     
         6 . The apparatus of  claim 5 , wherein the pockets extend partially into the pallet.  
     
     
         7 . The apparatus of  claim 5 , further comprising: 
 a pick-and-place mechanism for aligning the semiconductor substrate with the pallet and placing the semiconductor substrate onto the pallet; and    a heating device for heating the conductive materials so that they attach permanently to the conductive pads.    
     
     
         8 . An apparatus for attaching conductive materials to conductive pads on one side of a semiconductor substrate having other conductive pads on another side thereof, and for attaching a semiconductor chip to the other side of the semiconductor substrate, the semiconductor chip having solder bumps on one side to complement and connect with the other conductive pads on the other side of the semiconductor substrate, the apparatus comprising: 
 a pallet having pockets to receive the conductive materials;    a pick-and-place mechanism for aligning and placing the semiconductor substrate onto the pallet so that at least a portion of the pockets on the pallet are aligned respectively with the conductive pads on the one side of the semiconductor substrate, and for aligning and placing the semiconductor chip onto the semiconductor substrate so that the solder bumps on the one side of the semiconductor chip are aligned respectively with the other conductive pads on the other side of the semiconductor substrate; and    a heating device for simultaneously heating the pallet, conductive materials, semiconductor substrate, and semiconductor chip so that the conductive materials attach permanently to the conductive pads on the one side of the semiconductor substrate and the semiconductor chip attaches permanently to the other side of the semiconductor substrate.    
     
     
         9 . The apparatus of  claim 8 , wherein the pockets extend partially into the pallet.  
     
     
         10 . The apparatus of  claim 8 , wherein the pallet has passageways for applying vacuum force to the conductive materials in the pockets. 
 placing at least one marking onto the substrate; and    using the marking on the substrate to align the conductive pads on the other side of the substrate with the solder bumps on the semiconductor chip.    
     
     
         36 . An apparatus for attaching conductive materials to conductive pads on a substrate, comprising: 
 a plate having pockets, at least some of the pockets being located to align respectively with the conductive pads on the substrate so that when the conductive materials are placed into the at least some of the pockets and the substrate is placed onto the plate, the conductive materials contact and attach to the conductive pads on the substrate.    
     
     
         37 . The apparatus of claim  36 , wherein the pockets extend partially into the plate.  
     
     
         38 . The apparatus of claim  36 , wherein the substrate is placed onto the conductive materials in the pockets by a pick-and-place mechanism.  
     
     
         39 . The apparatus of claim  36 , further comprising a heating device for heating the conductive materials so that they attach permanently to the conductive pads.  
     
     
         40 . The apparatus of claim  39 , wherein the heating device is a heating oven.