Methods for placing substrates in contact with molten solder

Abstract

Methods and devices for placing a semiconductor wafer or other substrate in contact with solder are described. A wave soldering apparatus includes a solder bath, a nozzle for producing a solder wave, and a jig for orienting a substrate in a substantially vertical orientation and placing the substrate in contact with a cascading solder wave. In another wave soldering apparatus, a jig orients a semiconductor wafer in a substantially horizontal orientation in contact with the solder wave. Another soldering apparatus includes a tank comprising molten solder and a fixture configured to orient one or more semiconductor wafers in a substantially vertical orientation. Methods of placing semiconductor wafers or other substrates in contact with solder using the devices of the present invention are also disclosed.

1 . A method of placing a substrate in contact with molten solder, comprising: 
 placing at least one substrate adjacent to a solder bath having molten solder therein; and    directing the molten solder to an exterior of the solder bath and in contact with that at least one substrate.    
   
   
       2 . The method of  claim 1 , further comprising placing the at least one substrate adjacent to a preheating device for preheating the at least one substrate prior to placing the at least one substrate adjacent to a solder bath.  
   
   
       3 . The method of  claim 1 , wherein directing molten solder to an exterior of the solder bath comprises directing molten solder to an exterior with at least one of a solder nozzle and a solder wave guide.  
   
   
       4 . The method of  claim 1 , further comprising recapturing the molten solder after the molten solder has contacted the at least one substrate.  
   
   
       5 . The method of  claim 4 , wherein recapturing comprises cleaning the molten solder and returning the molten solder to the solder bath.  
   
   
       6 . A method of forming a solder bump on a substrate, comprising: 
 placing a substrate having a mask layer on a surface thereof and at least one opening exposing at least a portion of the surface therethrough in contact with molten solder to fill the at least one opening and contact the exposed portion of the surface of the substrate;    substantially solidifying the molten solder within the at least one opening; and    removing the mask layer.    
   
   
       7 . The method of  claim 6 , further comprising forming at least one solder ball from the substantially solidified solder.  
   
   
       8 . A method of placing a semiconductor wafer in contact with molten solder, comprising: 
 moving at least one semiconductor wafer in a vertical direction; and    immersing the at least one semiconductor wafer in a solder pot having molten solder therein.    
   
   
       9 . The method of  claim 8 , further comprising moving the at least one semiconductor wafer in a horizontal direction while immersing the at least one semiconductor wafer in the solder pot.  
   
   
       10 . The method of  claim 8 , further comprising preheating the at least one semiconductor wafer prior to immersing the at least one semiconductor wafer in the solder pot.  
   
   
       11 . The method of  claim 8 , wherein immersing the at least one semiconductor wafer in a solder pot having molten solder comprises immersing the at least one semiconductor wafer to a select depth of the molten solder.  
   
   
       12 . The method of  claim 8 , wherein immersing the at least one semiconductor wafer in a solder pot having molten solder comprises completely immersing the at least one semiconductor wafer in the molten solder.  
   
   
       13 . A method of placing a semiconductor wafer in contact with molten solder, comprising: 
 producing a molten solder wave; and    moving a semiconductor wafer in a substantially horizontal direction and in contact with the molten solder wave.    
   
   
       14 . The method of  claim 13 , wherein producing a molten solder wave comprises producing a molten solder wave in a substantially horizontal direction opposite the direction of movement of the semiconductor wafer.  
   
   
       15 . The method of  claim 13 , further comprising forming at least one opening in the semiconductor wafer and coating the at least one opening with a material layer before movement thereof in the substantially horizontal direction.  
   
   
       16 . The method of  claim 15 , wherein coating the at least one opening with a material layer comprises coating the at least one opening with at least one of a copper material and a nickel material.  
   
   
       17 . A method of filling an opening in a semiconductor wafer with molten solder, comprising: 
 contacting at least one opening in at least one semiconductor wafer with molten solder; and    displacing air in the at least one opening during the contacting.    
   
   
       18 . The method of  claim 17 , wherein displacing air comprises displacing air by placing the at least one semiconductor wafer in at least one of a substantially vertical orientation and a substantially vertical orientation at an acute angle to the vertical.  
   
   
       19 . The method of  claim 17 , wherein displacing air comprises displacing air by vibrating the at least one semiconductor wafer with a vibrator.  
   
   
       20 . The method of  claim 17 , wherein displacing air comprises displacing air by moving the at least one semiconductor wafer in a direction substantially traverse to a plane of the at least one semiconductor wafer.