Temporary chip attach using injection molded solder

Abstract

An improved method for performing an improved Temporary Chip Attach utilizing an Injection Molded Solder (IMS) process to allow efficient testing of die for creating a Known Good Die Bank. The IMS is applied to the testing substrate to form a column on the substrate. The die to be tested can then be attached to the IMS column with C4 solder. A slight reflow is then applied to the die, allowing some of the C4 to melt, and form an electrical connection with the corresponding IMS column. After testing, the die can be removed along with the C4 from the IMS column or permanently attached the substrate by performing a full reflow of the C4.

1 - 19 . (canceled) 
   
   
       20 . A structure for attaching a chip to a substrate, comprising:
 a bottom end of an injection molded solder column disposed on a substrate, the solder column being of a first solder having a high melting temperature;   a chip mounted onto an opposite top end of the injection molded solder column with a second solder having a lower melting temperature than the first solder; and   said second solder disposed about a side wall of the injection molded solder column so as to form a joint between the substrate and the side wall of the injection molded solder column.   
   
   
       21 . The structure of  claim 20  wherein the ring of a high temperature third solder is disposed on the substrate to form an outer region disposed about and spaced from the side wall of the injection molded solder column so as to prevent the low temperature second solder to flow across the substrate beyond the outer region.